NTES serves up new lighting for Bolton Arena's tennis facilities
To remain a world-class tennis centre, the Bolton Arena Sports Village in Greater Manchester must provide state-of-the-art facilities.
Its status as the Lawn Tennis Association's regional development centre meant that the 15-year-old fluorescent tube lighting at its eight indoor tennis courts had to be upgraded. Not only was the lighting energy inefficient, but the lux levels couldn't be adjusted for different events.
Bolton-based NT Electrical Solutions (NTES) was appointed to install the new high-level lighting after tendering for the job, but finding the most appropriate high-level lights proved challenging.
"There isn't much on the market for high-level light fittings, particularly
where the lux level for tennis courts is guaranteed," says Justin Plimley at NTES. "But then lighting manufacturer Luceco contacted us because we'd previously worked with them, and they recommended their Luxbay ULTRA."
The LuxbayULTRAis ahighperformance specialist LED luminaire designed for high-level applications. The lights are housed in aluminium and have polycarbonate lenses with specially designed lens optics to ensure installation points are maximised. Crucially, the lights have five light settings that can be controlled remotely via a phone app, enabling tailored control oflight on each court.
Bolton Arena wanted three different lighting scenes: 300 lux in the morning for the cleaners, 500 lux for general
tennis use and 800 lux for championship tennis events. After the lights were installed, the lux levels were set using a computer-controlled light meter.
Plimley says installing lights 15 m above the ground using scissor lifts, and working while the courts were still in use weren't the key challenges. The trickiest bit was the rewiring, which took two weeks.
"The cables sat on top of 600 mm baskets suspended 1 m from the ceiling and we had to run the cables from the courts to the plant rooms [where the distribution boards sit], which are located outside the arena's perimeter on the third floor," says Plimley. "This was very difficult to do but it all went well, and the new lighting produces a much cleaner light on the courts, which looks great."
DDN'TAEAD THISMAG DUASHORTCUT
TOTHEBESTBITS
7 OVERTD VDU,PAUL
...
NICEIC Technical Director
Paul Collins looks at how you can boost the success of T Levels, improve your team's mental health and make the most of assessment and CPD
24 RACK 'EMUP
This one is all about clever compartments
As
33
The big issues affecting the industry, including changes to standards
38
Our helpline heroes answer your questions
66
An assortment of facts, stats and stories to spark your interest
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All rights reserved. This publication (and any part thereof) may not be reproduced, transmitted or stored in any format without the prior written permission of the publisher. Think Publishing Ltd accepts no liability for the accuracy of the contents or any opinions expressed herein.
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highest quality and environmental standards. Both the magazine and the paper wrapper are fully recyclable.
Welcome to the summer issue of Connections magazine. This issue is packed with inspiring stories, insightful perspectives and technical articles from our industry experts to help you navigate the opportunities and challenges facing our industry.
If we want our industry to have a strong future, it's crucial to attract young talent to address the skills gap. And that's where T Levels come in. Having been on the advisory board for the design ofT Levels, I'm excited about their potential to bridge the sector's skills shortage. While some existing technical qualifications will lose funding in September 2024, there will be a wide range of21 T Levels available, which will help attract more young talent into the industry. The key to their success lies in employer participation. During their work placements, T Level learners can apply their knowledge in a real-world setting. By offering work placements, you can help build a pipeline of
qualified electricians for years to come. Read more on page 27.
Of course, running a successful electrical business extends beyond having the technical knowledge and skills to carry out the work. You also need to be able to navigate conflict and have difficult conversations. On page 12, we have practical advice on these issues. And on page 10, there's the inspiring story of Carl Lucas, an apprentice who shares his experience of overcoming mental health challenges with Danny Dyer on his Channel 4 show How to Be a Man. The EIC offers valuable mental health resources to those facing challenges in the sector. To show my support, I'm cycling 54 miles in a sponsored ride this September. Wish me luck!
Lastly, make sure you're logging CPD activity for everyone employed by your business. This magazine is packed with information that you can record as CPD, with more details on how to do this on page 18. You can also find CPD templates on our website and at the bottom of our regular newsletters.
I hope this issue provides you with plenty of material to help you stay informed, and to prepare you for a successful summer season.
Paul Collins Technical Director, NICEIC
Q: How did ATI get into boxing?
A: We were finding some of our 45 staff either had, in the past, or were currently having mental health issues. We offered some employees help through talking therapies, but only one person took that up. We found people were closed off to opening up in this way, so we tried boxing training.
We approached the West London Boxing Academy and Darren Harrison from Hurricane Training UK regarding some sessions, while they were in the
process of setting up a foundation called 'Everyone's fighting something' to help people with mental health issues. We thought using their coaching and training could be a good way to help the team.
We also thought it was a good way of getting people together to maybe talk and share with each other, building relationships through the training and outside work, and to be a support network for each other.
Q: How did you end up on TV?
A: After our first training session at the academy, the TV production company Whitworth Media got wind of what we were doing and asked us to be part of Danny Dyer's How to Be a Man programme.
Q: What was the take-up for boxing training?
A: It's been a success; 12 people trained on the first night, some of
them stuck with it and we have a regular five or six who still train together weekly (funded by ATI) at Hurricane Training.
Q: What have you learned from this intervention?
A: Firstly, it has made us aware, and in being aware we can check in with those who have suffered or are suffering, and hopefully offer them support in a way that works for them.
Q: How has boxing helped your apprentice Carl Lucas?
A: Carl was brave enough to put his hand up and take on the challenge of the white-collar fight, but also to share his struggles with the team. On the face of things, he is a happy, energetic character who you wouldn't think had challenges, so we think he really helped others come forward.
The training journey towards his fight also brought the team closer
together. Everyone was able to be a part of some of the training, and of seeing him grow and the positive impact it had on him. And of course they could be there and watch all the hard work pay off when he won a very tough fight.
Q: What impact has it had on the business?
A: There have been many positives. We think the team really appreciate being at a company that cares, and they're comfortable bringing up these issues now. It's brought a stronger team feel too, which helps out in the field and day-to-day at work. Productivity will always be better if people are happier, feel supported and are working as part of team that is there for each other. And we expect staff retention to be much higher too.
Q: What else are you doing, beyond boxing training?
A: We now do quarterly social events, and we have a team Snowdon trek planned for July, fundraising for a children's charity.
We encourage staff to take on personal challenges, like the London marathon, which we'll support. We feel that anything that gives people a focus and goal will help them mentally, and we support those challenges.
Q: Any advice for other owners of electrical businesses?
A: Having seen the positive results on ATI and those within it, we highly recommend investing some time on your team's wellbeing. Probably the biggest tip would be to stick with it and try different things; people rarely open up straightaway, and no two people will respond in the same way. Also, doing things together can be a much better way of getting people to open up, rather than sat across a table asking them if they're OK.
.WHENTHINGS
PaulThompsonexplores howtodealwithdifficult conversations and de-escalateconflict
We've all been there. Waking up in the morning with a feeling of dread. Today is the day that you're going to have to have that tricky conversation you've been putting off for a while. Unfortunately, there's no avoiding it. The time has come.
Being nervous about a potentially awkward encounter is entirely natural. No one relishes the thought of a 'difficult conversation', but what defines one?
According to NICEIC's Learning and Wellbeing Manager, Danny Mouskovias, it's "any situation where the needs, wants, opinions or perceptions of the parties involved are diverse, and their feelings and emotions are running strong".
It's a definition that points to situations that will be more than familiar to most. Certainly those who tuned in to watch the recent webinar
Mouskovias hosted on NICEIC's THE WIRE reeled off a flurry of instances that they deemed 'difficult'.
Many cropped up time and again, from conversations with clients about deadlines and invoice payments to chats with employees over disciplinary action or redundancy.
So how do you deal with these types of conversation? And how do you de-escalate them if they start to turn ugly?
Keepcalm
"It's important to keep calm and stay in control of your emotions," says Mouskovias. "The emotional side of the brain tends to take over in these situations -that's common in all parties. It's just a human instinct, so it's important to control that side. Without that it's very difficult to reach a settlement that will be positive for all involved."
That's easier said than done. However, the key to gaining control over the emotional side of the brain is to recognise what's happening. Only then is it possible to try to take the heat out of the situation and wait until the emotional
response has died down -on both sides of the discussion.
"As humans, we're unable to make rational decisions until we've got through the emotional response," Mouskovias explains. "We often say things in the heat of an argument and regret it later. That's the emotional side taking control."
He suggests some techniques to get beyond that.
Introducing a pause in the conversation can help to calm the brain's emotional response and kickstart its rational side. Something as simple as suggesting a cup of tea can help provide that break. Or it can be about stepping back and taking time to listen to the other side of the discussion.
"Frustration and conflict arise when we feel we're not being listened to. If you take the time to listen to the opposite side, then that can help switch the brain over from the emotional, combative side to the more rational," Mouskovias explains.
GETUGLV
He advocates the 'LEARN' technique to help reach a level of compromise. This acronym for 'listen, empathise, apologise, reassure, next steps' should enable some level of agreement to be reached.
"The 'apologise' part is sometimes questioned. I'm not suggesting admitting any blame -but to apologise for the way the other party feels and then reassure them that you both want a positive outcome before agreeing on the next steps to take," he says.
Clearcommunication
Avoiding the likelihood of an awkward conversation in the first place would be ideal. This is where clear communication is vital, according to Liz Rivers of mediation specialist IPOS Mediation. i "Disputes often arise when there's ] been a lack of clarity. It's essential to be § clear and honest about everything right from the start of a project, and if things -§, start to go wrong or you make a mistake, ..9 then face up to that as soon as possible. If §s:: you don't avoid an issue when one arises, then you will find people are more willing B ui to understand," she explains.
If you've tried every approach and the relationship has soured to the point that litigation seems inevitable, then bringing in an outside mediator such as Rivers might be the best route. Lawyers are expensive beasts and reaching an agreement before they get involved can work out for the best financially.
But if you're still negotiating the aftermath of a difficult conversation that you haven't de-escalated quite as well as you had hoped, then Mouskovias has some more prosaic advice.
"Have an exit strategy. Know where you've parked your car and how to get away quickly. If you feel unsafe at any point, get out of there," he says.
Tharing trade tips esting hardwa;, ~ur best work can
and showing o . Ythe crowds. One certainly dr~w i~hat has more than electrician doing Just TikTok and another 3 30 000 followers on One of his clips . ' I tagram. This 115,000 on ns 1 2 million views. has had more than •nt king ofTikTok, guy may be the cu;~; competition out but there's somels itrician has racked there ec there.Ano
up 2.6 million hits for a failed prank on his workmate. And another has scored 6.2 million views for his story of how he nearly got electrocuted.
These are huge numbers. And there are a dozen other electricians on the UK social media circuit who could call themselves internet famous. They are proving social media is an efficient way to communicate to the online world. Forget costly online adverts -TikTok, Instagram, Face book and YouTube are an affordable way to market, costing nothing more than an hour or two of video editing. It may be tempting to follow them. But before you dream of becoming the electrical world's answer to Mr Beast (254 million followers on YouTube), there are some rules you should follow.
Abidebytherules
"Social media is a huge advertising platform," says NICEIC's Head of Technical Advice and Practice, Sam Donaghy. "Maybe you want to display your expertise in a certain area, such as floodlighting or fitting solar panels. Or maybe you just want to connect with other electricians who can be enticed to work for your organisation. There are many upsides, but you need to be careful."
The first rule is to follow safety procedures. "Never film for social media when working in a live environment," says Donaghy. "That is an electricity at work regulations statutory requirement. Just the idea of introducing a camera makes me nervous. You will be concentrating on filming, not on keeping yourself safe. Don't risk it."
Another rule is to be professional at all times. Social media is a magnet for tomfoolery -the algorithms reward unusual or extreme behaviour. "It's important to behave professionally when using social media," says NICEIC's Head of Marketing and Communications, Sarah Gammon.
"Remember, how you speak can have a negative or a positive effect on your business brand and therefore your reputation. NICEIC scheme rules have been updated to clarify our stance on the use of social media. These rules stipulate that you must not make use ofNICEIC social media channels, or other social media channels, in a way that is likely to bring NICEIC, an NICEIC scheme or the industry into disrepute."
Some pranks, slating other tradespeople and mixing politics with business may veer close to the mark.
NICEICbranding
Gammon says: "New guidelines for NICEIC-certified businesses on how to use the NICEIC brandmarks explain how to use them to ensure the brand is as strong as possible." The brandmarks and guidelines can be found in your NICE IC customer portal.
She emphasises that with proper usage the NICEIC brandmark is a huge bonus. "Using an NICEIC brandmark on your website, letterhead, social media and other materials shows your customers you're certified and upholding the highest standards. It can help you attract new business and secure existing
"UsinanNICEICbrandmark ... showscustomersou're the higheststandards" SARAHGAMMON
business. Some companies will only employ NICEIC-certified businesses because they know how robust our assessment processes are. Please remember, how you use an NICEIC brandmark reflects on our reputation too, so it's important that you use it correctly and consistently."
Then there's the issue of user comments. One blogger labelled his comment section "the ramblings of the insane" and there's a touch of truth to this. Anonymous commentators, trolls, teenagers and other malcontents love to provoke. Gammon and Donaghy agree that responding to negative comments is rarely advisable. "Would you say this if they were standing in front of you?" asks Gammon. "Comments you make will remain visible long after you made them, and they can reflect negatively or positively on your work and company brand."
Timetoshine
Overall, though, the pros of social media marketing outweigh the cons. A strong Linkedin page reassures potential customers that you are a reputable supplier. A Face book or Instagram page may be a great platform for showcasing your best work, as well as showing the human being behind the tools.
Naturally, one of the best ways for new customers to find you is through the 'find a trusted NICEIC tradesperson' tool. However, developing a social media presence can be a formidable way to build your brand, woo customers and even pass on a tip or two. Following the rules means you'll grow your online presence for the right reasons over the long term.
NICEICis the name in the electrical and building services sector that's trusted by customers across the UK.
Our electrical and renewable technology training courses and qualifications will support your business growth, build your skills, and help you keep up to date with your changing industry.
I ogue trainers offer packages that look attractive to the untrained eye, but leave learners paying thousands of pounds for qualifications that aren't required for qualified electrician status and don't give them the full range of skills they need.
Since the launch of our Rogue Trainers campaign, we've been contacted frequently by people who believed they were training to become a qualified electrician, but sadly found that wasn't the case.
The recent demise of training provider Options Skills has been a wake-up call to the industry, as around 1,500 learners have been left in the lurch after paying thousands of pounds for packages of training courses that promised a fast-track route to qualified status.
It's really important that all aspiring electricians know the correct training routes -and what to avoid. If you have friends or colleagues looking to become
qualified but don't know where to start, please share this advice with them.
1 Take one course at a time. We strongly advise against paying out for expensive training packages that tie you in and contain unnecessary courses or qualifications. If you're considering a package, check carefully what's included. Many contain courses that aren't essential, or are unsuitable for new entrants and aren't required for NICEIC or Electrotechnical Certification Scheme (ECS) card applications. Don't be taken in by terms such as 'professional electrician' or 'full scope electrician'. These aren't official terms and most of these packages contain a mix of knowledge qualifications and other courses that are best taken only once you've qualified.
2 Work-based training is essential. The classroom-based qualifications you'll gain at a college or other training provider
can be a good foundation, but on their own they don't mean you're a qualified electrician. You can't qualify without working in the industry.
3 Avoid hard sells. Most providers want to do the right thing and will happily answer questions. Be wary if you're being pressurised to commit to anything without having time to reflect or check out any claims, especially if you're being asked to enter into a financial agreement. Reputable providers will have detailed information on their websites, including prices.
Our Rogue Trainers video campaign warns against certain training packages and has advice on the qualifications commonly found in these 'bundles' and what they actually provide. Check out the Rogue Trainers website for recognised training routes: roguetrainers.co.uk
NICEIC-certified businesses are required to provide documented evidence of continuingprofessional development[CPD] forall'employed persons',includingsubcontractors,whocarry outelectrotechnicalwork.
he electrotechnical assessment is a key part of your certification with NICEIC. It ensures businesses are meeting the standards required for certification, and have suitable policies, procedures, systems and insurances in place.
During assessments, assessors look for appropriate evidence of CPD. But having a robust CPD framework isn't just about ticking compliance boxes. It shows you're investing in your people, which nurtures and enhances skills, and helps retain employees. We know there's a skills shortage in the industry, and that keeping good staffis more and more challenging. CPD helps you to do that.
CPD also helps ensure your business is keeping up with innovations, which can open up new markets. You might want to widen your portfolio by moving into green technologies such as electric vehicle charging points, solar PV and battery storage. But you can't do this work without staff with the right skills and knowledge.
Theofficeauditiskeytocompliance
During the management systems review stage of the assessment (previously known as the office audit), assessors request to see a record of supervision and training for all 'employed persons' (which means anyone engaged by the business to do electrotechnical work), and this includes relevant CPD records. You must make the records available for your assessor to review on the day of assessment.
Maintaining competence through CPD is a key part of the Electrotechnical Assessment Specification (EAS), and CPD includes formal and informal activities. It's good practice to have a framework for assessing the effectiveness of the CPD your employees and contractors do.
Businesses are also required to hold records ofrelevant qualifications, training (including CPD) and experience. This can be shown through documents such as personnel records, training matrices and contractor records.
We find that most people are doing CPD, but not recording it. It's important to log it for all employed people, including temporary, agency or sub-contracted staff.
NICEIC has produced a CPD record template, or you can create your own CPD recording system. If you're a member of a professional body, you're probably logging your CPD on their portals. The EGA's eCOMS platform also captures CPD.
There's no minimum number of hours of CPD specified. But you must be doing something, and it must be something that takes you forward in your role, so you're not just resting on a qualification you obtained many years ago. It's a key part of development, and CPD should be ongoing throughout your career.
In the past, people have seen CPD as predominantly formal class-based learning, but it can be done in different ways. Informal CPD includes watching an NICEIC webinar, reading an article in Connections magazine, looking at our Pocket Guide app, listening to live Technical Q&As, doing peer-to-peer reviews or shadowing. Formal routes include courses, via e-learning or in the classroom. When you record CPD, it doesn't have to be categorised as formal or informal.
Any activity from which you learn or develop professionally is eligible for CPD, though you should ensure it complements your role and enhances your knowledge and skills. CPD can come from:
Work-based learning
For example, reflecting on experiences at work, considering feedback from colleagues or customers.
Professional activity For example, being involved in a professional body or giving a presentation to work colleagues and the like.
Formal education
For example, going on formal courses or carrying out research when installing a new product or equipment.
Self-directed learning For example, calling the NICEIC technical helpline, reading books or articles, including Connections, or watching NICEIC technical seminars and webinars.
What CPD information should you record?
For each CPD activitY,you need to capture the essentials. Briefly describe what you did Oikejoining a webinar, reading a Connections article or taking an online course). Note the date and how long it took (number ofhours). Then
highlight the key knowledge and skills you gained. Most importantly, explain how this activity contributes to your professional development.
Who's responsible for recording CPD?
The assessed business is responsible for providing records of all relevant qualifications, training (including CPD) and experience for everyone engaged in electrotechnical work in the business.
Is CPD a recognised qualification?
No, CPD isn't itself a
NEXTUP: SUPE~VISION
In thespringl!Ol!4issueof Connections,weexplored the most commonnonconformances. In our autumn l!Ol!4issue,we'lldelveinto supervision.
you can record relevant qualifications as CPD.
What are the benefits of CPD beyond meeting requirements?
CPD equips you and your employees with the latest skills, knowledge, experience and behaviours (or SKEB). However, CPD goes beyond meeting requirements. It builds customer trust and qualification. It's a process of keeps you at the forefront of ongoing learning to stay up to the industry, which helps you date in your field. However, stay competitive.
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ConorMcDonnell
NesbittElectricalandSouthern RegionalCollege
After picking up the bronze medal in Oldham's final and becoming a qualified electrician, Conor McDonnell is now looking forward to expanding his electrical knowledge by taking up the training course prizes offered by NICEIC. "They are there to take and I will. They will give me another string to my bow."
He entered the competition "because I thought it would be a challenge. I wanted to see how far I could go and get my name out there."
McDonnell has also been focusing on making the transition into self-employment.
ThomasTurner
EJParkerTechnicalServicesand JTLTraining
The electrical trade runs strongly through Thomas Turner's family. His brother and father are electricians, and the prestige of getting to the SkillELECTRIC final last year has given him temporary bragging rights at home and stood him in good stead at work too.
"It certainly put me in the good books at work I've been given more responsibility, and my managers are happy to let me get on with the work I have by myself," he says. At the moment, he's happy being on the tools and wants to continue getting as much experience as he can, which includes completing the training course prizes. "There's no point me trying to price anything up ifl don't know how to install it," he adds.
Having qualified as an electrician since the final, Demi Mae Whitehead has been using some of the exposure she gained from the competition to help encourage more women into construction through the trades, and has even been interviewed on BBC Radio Leicester about the industry.
Now, she is focused on gaining as much experience as possible with her current employer, despite harbouring dreams of working for herself at some point.
'Tm really happy on site at the moment. William Davis has been really good to me. It's not too big a company -I feel like I have a voice there, which is really helpful," she says.
As for the final, she adds: "The whole experience was a fantastic learning opportunity. It helped me plan my work better and helped me realise that I can work well under pressure. It also helped me to recognise the positives about mywork."
KevinBoone
Darke&TaylorandXSTraining
For Kevin Boone, even entering the SkillELECTRIC competition at all was something of a gamble. Getting through to the final stage was a massive bonus.
Boone had been a bomb disposal technician in the army for 17 years. "I was struggling to find work after I'd come out of the forces and hadn't secured my current role," he says. "I entered to prove both to myself and others what I was capable of"
That decision certainly seems to have paid dividends. He's another 2023 finalist who is busy mentoring a fresh crop of apprentices hoping to emulate his performance in last year's competition.
Given his experience in his previous career, a move away from site and into a more managerial role looks on the cards, but at the moment he is happy gaining as much on-site experience as possible.
"I have a great relationship with everyone at Darke & Taylorthey've been fantastic with me," he says. "The competition has been a massive profile raise. It put me on the company map and has given me the opportunity to make connections across the wider industry."
BenGillin
LloydMorrisElectricaland JTLTraining
Wrexham-based SkillELECTRIC silver medallist Ben Gillin is keenly aware of the boost doing so well in last year's competition has given him, and is taking up the training opportunities in EV charging and energy storage systems that NICEIC offered as prizes to the finalists. 'Tm looking forward to expanding my understanding in both areas," he says.
"I've been given more responsibility at work. They trust me to run smaller jobs here and there," he says. "Once I finished my apprenticeship, my boss and I talked through my options. For the time being I am focused on gaining as much experience and expertise as possible."
Gillin is a huge advocate of the competition and, although not entering again this year, has been spending time mentoring the next generation of electricians coming off the Lloyd Morris Electrical apprenticeship conveyor belt.
Working alongside his own mentor and former SkillELECTRIC finalist Tom Williamson, Gillin is helping hone the skills of a secondyear apprentice who the two hope will shine in this year's SkillELECTRIC competition.
Thelatesthowlers spottedby vigilantreaders
Joe Bellis at Ellgen Electrical in Liverpool received a call-out in nearby Huyton for an intermittent RCD problem and a burning smell. It turned out to be an inaccessible badjoint found within a stud wall. "We had to drill small holes for a camera to locate the joint before we drilled 4-inch access holes in the wall to access the cables to repair," he explains.
Kelsall McEwen of Greener Building in Scarborough was brought in to find out why this place had no heating. "I found a dead woodlouse trapped between the contacts of the thermostat. Nice easy fix ...but not something I'd seen before." Once he'd removed the woodlouse the thermostat could work again, so the heatingwas back on. "The thermostat is a switch and the woodlouse was blocking the contacts," he adds.
DanKennyofDK
Wired in Greater Manchester came across this when he was carrying out an EICR: "Clearly a C2. Needless to say, the rodent wasn't trained in classical music, but did a very good job at being the conductor." Boom,boom!
Calvin Mansell ofBrightech
Construction in Southampton discovered here that the builder had built a stud wall in front of the original switch, and used twin and earth rather than three core to extend the cabling. "Sleeved brown CPC-we rewired it!"
HIGHSECURITU
Thevanwithcunningcompartmentstopreventtheft
The owner of this VW Transporterwho celebrates his 30th anniversary as an NICEIC-certified business this year -has made good use of its two side doors. He has built himself three compartments, all separate from each other and each accessed from a different door. "If anyone breaks in, they can only get into one compartment," he explains. The van is also fitted with a tracker and immobiliser, and has dead locks on each door.
He made the racking himself in chipboard, having learned what works for him with similar racking in past vans.
He carries out commercial, industrial and domestic work and says: "When I get to site, I usually have what I need to hand."
The false floor he put in creates a space for steps, ladders and long equipment such as lengths of plastic conduit, long spirit levels and metal channels.
The passenger-side compartment houses the power tools he uses frequently, as well as battery drills, hand tools, fixings, cutters, a selection of crimps and a first
aid kit. The boxes from left to right contain junction boxes, saddles, cable plugs and a range of circuit breakers to fit different boards. He uses clear plastic boxes, so he can see what's where.
On the driver's side is equipment that gets used less regularly, such as mains drills, breaking equipment, coring equipment, a vacuum cleaner, and 110V equipment and testers, which get taken out every night. This side also carries safety goggles, ear muffs and high-vis jackets.
At the back he keeps a set of regs books and guides, as well as spare equipment such as sockets, switches, cables, junction boxes and glands -"all sorts that are used on a daily basis".
The size of the shelves is based on what needs to be stored, so everything fits snugly. Despite packing a lot in, he has left enough room in the back -a gap 620 mm wide -to carry appliances such as fridges or washing machines.
There's even room on the right-hand side for a hydraulic trolley jack, "in case I have a puncture with all this weight in the back".
A discussion on all things T Levels featuring key interviewees from this article by clicking here
The BSE T Level is attracting fresh talent into the sector –and your company can help nurture this new generation
By David Adams
ET LEVELS: THE FUTURE OF ELECTRICAL EDUCATION?
lectrical contractors have a key role in the UK’s transition to net zero, but there aren’t enough of them. The UK Trade Skills Index for 2023 says the construction sector will need 104,000 more electricians by 2032, among more than a million skilled workers needed in 11 different construction trades by then.
The best way to address these skills shortages is to attract more young people – including women – into the built environment industries. Might T Levels, a relatively new type of technical qualification, help bridge this gap?
One T Level is the equivalent of three A Levels, and these twoyear courses combine academic content with technical training, including a work placement of at least 315 hours (45 days).
By September 2024, 21 different T Levels will be offered across the UK, including the Building Services Engineering (BSE) for Construction T Level. Launched in 2021, its core
component teaches about the wider construction sector, and its occupational specialism options include electrical and electronic engineering, or electrotechnical engineering (see boxout, left).
The ESE T Level for Construction is offered by more than 80 colleges and education providers around England (while Scotland, Wales and Northern Ireland retain different training pathways). However, with 158 general further education colleges in England, plus more training providers, there is plenty ofroom to increase that provision.
NICEIC Technical Director Paul Collins was on the advisory group that helped design the T Level. "It will train someone to the point where they are useful, but not the finished article," he says. "They'll have more overall knowledge about the building services and construction sector than if they had completed an apprenticeship straightaway. But they can also then transition to an apprenticeship." With a T Level under their belt, they should cut months off their apprenticeship.
Roll-out of this T Level means funding for some older technical qualifications, including intermediate and advanced diplomas in electrical installation, will end in September 2024. But these qualifications rarely included work placements, and between 2017 and 2020 only around 10% oflearners who completed these diplomas and certificates moved on to an electrical apprenticeship, according to research compiled by the Electrical Contractors' Association (EGA) and training company JTL for The Electrotechnical Skills Partnership (TESP).
Opportunityknocks
TES P's Skills Ambassador, Nathan Smith, thinks the ESE for Construction T Level could be "a very good option" for someone considering working in the built environment industries but who's not yet sure. That's because the course reveals the full range of career opportunities in these industries. He also thinks the broader nature of the course might encourage more young women to consider this sector.
Leicester College was an early adopter ofT Levels and around 60 students take the ESE for Construction T Level there each year. Derek Watters, who leads delivery of the T Level at the college, says learners tend to head in three different directions afterwards. Around 5-10%
go on to higher education, while another small group go straight into employment. The most common destination is an electrical apprenticeship.
In 2023, around a fifth of Leicester College's T Level learners failed to complete the course because they were offered an apprenticeship mid-course. This is positive, but has some downsides.
"If that's what you want, that's great -but you won't get an appreciation of the construction sector as a whole or see all the opportunities it can offer," says Watters. Learners at Leicester are also given the opportunity to complete the City & Guilds 238218th Edition Wiring Regulations course after their T Level and before starting their apprenticeship.
Furthermore, the ECA's Chief Operating Officer,Andrew Eldred, points out that in previous years about
20,000 young people enrolled on the older technical diplomas and certificates. Defundingthem will create problems for some colleges. ''I'd be very surprised if the further education sector has the capacity from September to take 20,000 people on to T Levels," he says. "So there'll be a significant contraction oflearners coming through those courses. Some might say this is good, because very few people progressed from those courses to an apprenticeship. But the jury is still out as to whether T Levels are going to be better at that."
Workplacements
The element of the T Level that really makes a difference is the work placement, but finding willing employers could be a challenge over the next few years. The many electrical contractors that are small or micro businesses may struggle with
the practicalities, such as the costs and logistics of getting a learner on site and appropriately equipped.
Oldham Collegehas offered the T Level since 2021, and its 2023/2024 cohort comprises 50 electrical and 23 plumbing learners. Tom Leahy, Oldham's Head of the Department of Building Services, Construction and Motor Vehicles, says a lack of Construction Skills Certification Scheme (CSCS) Alliance cards was a barrier to the first cohort o{ learners working on building sites. ECS • ••••:::r.::-::::::m: (electrical), PMES (plumbing) and othei-. ::::•::;::::i;i:i;ii:i
ThiswillbebigI
CSCS Alliance scheme operators now offer specific cards for T Level work placements. So far, it hasn't been difficult to find work placements, but he wonders "if this might change as learner numbers keep growing".
"There are always going to be challenges getting employers to offer work placements," says Kevin Sparrow, Industry and Portfolio Manager for BSE at EAL, which worked with City & Guilds to create the BSE for Construction T Level. "Contractors may not be thinking about supporting the talent pipeline [but] ...work placements provide a hands-on feel as to what this kind of work is all about."
Getinvolved
Could your business offer T Level work placements? Contractors as well as learners benefit. Businesses might spot a good candidate for an apprenticeship or a future full-time role. And it can be good for publicity: "You're helping the next generation and it sets you apart from [competitors] who aren't engaging," says Smith at TESP. The organisation is running a campaign with educational charity the Gatsby Foundation to help businesses find out
more about T Level placements, their benefits and the support available.
NICEIC-certified Lewin Electrical Services in Leicester already offers T Level placements. The company has two employees and hosts five T Level learners on different days each week. Owner Daniel Lewin says each learner, aged 16 or 17,has slightly different attributes and requirements. "We're having to provide extra support for some, but others we can leave to get on with stuff," he says. "The ones who are over-confident are rushing too much, and [we try to] encourage the ones who aren't confident."
What would he say to other NICEICcertified businesses considering getting involved? "Give it a go. It's about nurturing 8 somebody at the start of their career, and ] then you've got your apprentice if you en want them."
Raisingstandards
Alex Robinson, Lead Technical Advisor for BSE at EAL, thinks the T Level will raise standards. "Young people coming through this system will be more confident, with knowledge of the sector and things like project management, alongside technical skills."
Sparrow backs this up, adding: "It'll change things for the better. A pipeline of young people undertaking a high-quality qualification helps secure a better pipeline into apprenticeships and other meaningful progression that will help the industry."
"It's an improvement on what's gone before -but it's only going to work if industry supports it," cautions Eldred.
NICEIC's Paul Collins agrees. "The sticking point is the work placement." Connections readers -for the future of your industry-it's over to you.
Thank you to all the NICEIC-certified businesses that gave feedback on a proposed amendment to BS 7671:2018+A2:2022. The need for additional clarity regarding unidirectional and bidirectional protective devices became evident through enquiries to our technical helpline. This feedback highlighted necessary change and informed the recommendations put forward in the Draft for Public Comment (DPC) by the Institution ofEngineering and Technology (IET) and the British Standards Institution (BSI).
The proposed amendment to the Requirements for Electrical Installations
BS 7671:2018+A2:2022 follows requests for clarity from Certsure and a bulletin from British Electrotechnical and Allied Manufacturers' Association (BEAMA) on the differences between connections for unidirectional and bidirectional RCDs and circuit-breakers.
"We welcomed the DPC, which addressed feedback we've gathered from NICEIC-certified businesses on this topic," says NICEIC Technical Director Paul Collins.
Mark Coles, Head of Technical Regulations at the IET, adds: "When issues arise, it's important that standards
take on the necessary changes as quickly as possible. This fast-track route to amendment will allow designers and installers to quickly get the information out to their clients and promote safety in electrical installations."
The IET and the BSI jointly manage the committee responsible for BS 7671. The final amendment is due to be published on 31Julyand will be free to download.
MCS CEO Ian Rippin has written an open letter to installers (see bit.ly/mcsletter) explaining the timeline for the launch of the redeveloped MCS. He says the new MCS is "fit for the future and accommodates the feedback that certified installers have given us". Because of the scale of the changes, the launch has been delayed to January 2025. The changes are:
1. Less focus on paperwork in favour of delivered quality.
2. Risk of non-compliance will determine the frequency of your assessments.
3. Standardised assessments.
4. Centralised customer complaint management.
5. A more direct relationship with MCS.
6. Consumer Code membership
HOW;;~;n;;IU • METERTAMPERING
Reports of energy theft have shot up by nearly 50%, according to Crimestoppers. Over the last 10 months, the charity has received more than 900 reports on average a month -that's an increase of 48% on the same period two years ago.
As well as being illegal, electricity theft is obviously very dangerous, leading to shocks, severe burns, fire and sometimes death. Electrical contractors can help stop this via Crimestoppers' Stay Energy Safe reporting service. If you spot a meter that's been tampered with, call the 24-hour service on 0800 023 2777, or fill out the form on the Stay Energy Safe website. Both ways of reporting are free and guarantee your anonymity. Crimestoppers doesn't ask for your name or address, but asks for the name and address of the suspected individual or company, which is passed immediately to the relevant supplier to investigate.
For more information, go to bit.ly/report-energy-crime or use the QR code.
NEWGUIDETDTHE NICEICBAANDMAAK
Using an NICEIC brandmark shows your customers you're certified and upholding the highest standards. Please help us to maintain our collective reputation by using it correctly. Our updated guide is free to download from bit.ly/NICEIC_brandmark_guidelines
NICEIC is once again supporting UK-wide skills competition SkillELECTRIC as a key delivery partner. All national qualifying heats for 2024 have now taken place and the highest scoring competitors have been invited to compete in November's UK final.
NICEIC Head of Technical Advice and Practice Sam Donaghy has judged the heats so far and every competitor has received the NICEIC Inspection, Testing & Certification book and the NICEIC Site Guide.
As SkillELECTRIC is part of the WorldSkills network, those who perform well and are age-eligible may also progress to compete internationally at the WorldSkills 2026 event in Shanghai, China.
To see how last year's finalists are progressing in their careers, go to page 20.
Screwfix's Top Tradesperson competition launched earlier this month (July), with the final set to take place during Screwfix Live at Farnborough International Exhibition & Conference Centre, 27-29 September. NICEIC's Technical Director, Paul Collins, is on the judging panel, and electricians will be up against other talented tradespeople, including plumbers, carpenters and heating engineers. They're competing for a trade bundle worth £20,000.
NICEICAT INSTALLERSHDW
At Birmingham's lnstallerSHOW in June, visitors to NICEIC's stand connected with industry experts and gained valuable insights into the everevolving landscape of the heat, water, air and energy sectors. A highlight was the session presented by NICEIC Head
of Standards Dani Putney and Energy Efficiency Scheme Manager Daniel Yeates, on 'Addressing the Renewable Installer Gap: routes to joining the low carbon market'.
Catch the lnstallerSHOW highlights in our next newsletter.
NEWALARM ANDSAFETV REGSINNI
Newstandardsonsmoke,heat andcarbonmonoxidealarmsstart to comeintoforceon1September i!Oi!4forNorthernIreland's privaterentedproperties.These regulationsinclude:
The latest new location for NICEIC training is Maidstone in Kent, where the Level 3 Award in the Installation of Small-Scale PV Systems and Level 3 Award in the Design, Installation and Commissioning of Electrical Energy Storage Systems will be on offer -keep your eyes peeled for dates.
TECHNICALHELPLINE ISHERETDHELP
DidyouknowthatNICEIC'stechnicalteamhas combinedelectricalexperience of morethan 450years?Learnmoreabouttheteammembers andthesupporttheyprovideforNICEIC-certified businessesinthecomingmonths.
Maidstone joins the six new training locations in Penkridge, Telford, Bristol, Dartford, Gatwick and Manchester, meaning the options for NICEIC training venues keeps getting better for our contractors.
For the latest on training courses, go to shop.niceic.com
We have been asked to install some additional lighting on existing circuits within a school. All of the additional lighting will be installed using surface-mounted conduit. However, the existing circuits that we are extending are wired using thermoplastic insulated and sheathed cables buried in the walls. Do we need to upgrade the circuits to include additional protection?
The alterations/additions that you are undertaking on the existing circuit(s) would need to meet the requirements of BS 7671 (641.5). However, this would not necessarily require the existing circuit to be upgraded, provided that there were no defects or omissions that would affect the safety of your alterations or additions.
Any defects identified on the existing circuits that would not affect the safety of your planned works should be recorded on the certification produced, in accordance with the requirements of regulation 644.1.2.
See also the article in this issue on additions and alterations (see Let's get technical, p54).
Can switching off a BS 3871 circuitbreaker be used to provide isolation?
BEAMA, formerly the British Electrotechnical and Allied Manufacturers' Association, states in section 3.2.2 of its publication Guide to Low Voltage CircuitBreakers Standards that while "circuitbreakers conforming to BS EN 60898 are suitable for isolation ... miniature circuitbreakers (MCBs) manufactured to earlier standards (such as BS 3871) are unlikely to be suitable for isolation".
As such, it would be necessary to seek advice from the particular manufacturer of a device to BS 3871 to determine its suitability, or otherwise, for such use.
This BEAMA guide, and many others ofinterest to electrical contractors, are available as a free download from the BEAMA website: beama.org.uk
We are working in a domestic apartment block and have been questioned over the types of cable supports that we have installed. Within the communal area where a suspended ceiling is to be installed, we have supported the cables using steel ties to a cable tray system. Within the individual apartments, where a solid plasterboard ceiling is to be installed, we have used cable anchors and plastic ties. Should these also be steel ties?
Regulation 521.10.202 requires that all wiring systems shall be supported in such a way that, in the event of a fire, they will not be liable to premature collapse and result in an entanglement risk.
Typically, for cables that are installed above a plasterboard ceiling, it is likely that the means of support will remain effective for long enough to allow persons to egress the building and for firefighters to enter the building and deal with the fire etc. All the time the cables are contained within the ceiling void, and the plasterboard is intact, they are protected from the effects of heat and fire. It should also be noted that even in the event of the plasterboards failing, the cables will pass through joists, where this is necessary for their routing, further limiting the likelihood of their causing an entanglement risk. For these reasons the use of plastic ties or clips in a floor void above a plasterboard ceiling is acceptable.
We have been asked to replace a number of fans within a domestic apartment block. The fans are to be replaced on a like-for-like basis, with no alteration being necessary to the.fixing wiring. Do we need to certificate this work?
NICEIC would recommend that details of the work carried out are documented using a Minor Electrical Installation Works Certificate (MEIWC), works order, job sheet or similar.
Is the provision of additional protection by a residual current device (RCD) required for the supply circuit to an electric shower installed in zone 1 of a location containing a bath or shower?
Yes. Additional protection provided by an RCD conforming to the characteristics specified in regulation 415.1.1 is required for all low-voltage circuits serving the location. It should be further noted that any low-voltage circuits passing through zones 1 and/or 2, although not serving the location, must also be provided with additional protection by RCD (701.411.3.3).
It delivers everything you need to enhance your knowledge, stay updated on changes to legislation and regulations, and give useful information to help you run your business. You can quiz our experts and engage with peers in the industry, all from the comfort of your own home or workplace.
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Objective: A previous article in Connections Issue 229 looked at what harmonic currents are, the types of load responsible for creating them and their impact upon the electrical system. This article will focus on the considerations for the contractor when encountering triplen harmonics within a three-phase circuit and the effects on current in the neutral conductor, which can mean an increase in the minimum conductor size required for the circuit. The implications of harmonics on overcurrent protection and voltage drop will also be considered briefly.
Fig 1 Three-phase waveform showing only the 3rd harmonic
When using single-phase and/or threephase non-linear loads such as electronic lighting ballasts/drivers and computer switch mode power supplies, typically in larger industrial/commercial type installations, the effects of harmonics within the three-phase distribution system can become more problematic, especially with the presence of'triplen' harmonic currents.
As the name suggests, triplen harmonics represent multiples of the 3rd harmonic i.e., the 3rd, 6th, 9th etc. although, due to their greater impact within a three-phase installation only the odd multiples of the 3rd harmonic are normally considered -for example, the 3rd, 9th, 15th etc. This is because even harmonics (2nd, 4th, 6th etc.) are rare in AC circuits as they generally cancel out, as discussed in the article published in Issue 229 of Connections.
The example shown in Fig l(a) highlights the 3rd harmonic current superimposed on the three-phase waveform which is in phase with all three phases. Where the harmonic crosses the zero point on all phases this is typically referred to as 'zero sequence'.
For simplicity, Fig l(a) only shows the 3rd harmonic in phase with all three phases. However, in reality the same effect holds true for the 9th, 15th, 21st and,
Three-phase distribution circuit Distribution board
Fig 2 Three single-phase loads supplied from a three-phase distribution board
similarly, for all odd multiples of the 3rd harmonic. These particular harmonics are called 'triplen' and are the focus of Section 5.5 in Appendix 4 of BS 7671.
Considerationsforthe designer/installer
The main concern for installation designers/installers is that with triplen harmonics being 'zero sequence' the magnitude of these harmonic currents are summative in the neutral conductor,
Three sing le-phase circuits
Load on each circuit = 10 A fundamental + 3 A 3rd harmonic
as shown in Fig l(b). In addition, the frequency of the neutral current will also increase to roughly three times that of the supply fundamental (150 Hz), predominately through the 3rd harmonic, although the accumulation of further triplen harmonics will have significant impact.
Triplen harmonics can not only lead to distortion of the voltage sinewave but, most importantly, result in the presence oflarge counterproductive current in the
Fig 3 Circuit diagram showing resultant line currents (except for the neutral of distribution circuit) Identifying the resultant neutral current in the three-phase distribution circuit
current in line conductors of distribution circuit = 10.44A
?
Total current in line and neutral conductors of each single-phase circuit = 10.44A
neutral which may lead to overload unless the neutral conductor is sufficiently sized.
Typicalscenario
To help provide a better understanding of the effects oftriplen harmonics on circuit currents, consider the installation example shown in Fig 2. This includes a three-phase distribution board supplying three single-phase circuits, each circuit having a fundamental current oflO A and a 3rd harmonic current of 3 A.
As Fig 2 indicates, it is necessary to determine the resultant current in the line and neutral conductors for each single-phase circuit before we can establish the resultant current in the line and neutral conductors of the three-phase distribution circuit.
It can be shown that for any conductor carrying harmonic current, the resultant circuit current (Irms)is given by:
Where:
h1 is therms (root mean square) value of current at the first harmonic frequency (fundamental current),
Ih1 is the third value harmonic current, etc.
In our example, the resultant current in the line and neutral conductors of each single-phase circuit is given as:
Irms~.Jl02 + 32 = 10.44A
As Fig 3 indicates, this value also represents current flow in each of the line conductors supplying the distribution circuit although the resultant current in the neutral conductor of the distribution circuit still needs to be determined.
In order to establish the resultant current in the neutral conductor of the distribution circuit we must refer to the previous waveforms and consider both the fundamental and 3rd harmonic currents in all live conductors of the distribution circuit (see Fig l(a)).
We should instinctively remember that the neutral conductor provides the return path for all three line currents, which subsequently combine in the neutral conductor. In a balanced threephase load, the fundamental currents in the three line conductors are equal
(a)Fundamentalcurrents
L1lh1= 10A
L2lh1= 10A
SupplyL3lh1= 10A
Nlh1=0A
(b)Harmoniccurrents
L1lh3=3A
L2lh3=3A
SupplyL3lh3=3A
Nlh3=9A
(c)Resultantcurrents
L1 I = 10.44A
L2 I = 10.44A
SupplyL3 I = 10.44A N I =9A
Distribution board
Fig 4 Diagrams of distribution circuit
in magnitude but are displaced by 120°. As expected, these currents cancel each other out, and consequently no fundamental current flows in the neutral conductor.
However, the situation is different in our example, which includes the presence of the 3rd harmonic currents in the three line conductors. These currents are in phase with each other and equal in magnitude. Consequently, like all triplen harmonics, their magnitudes add together directly in the neutral, as shown in Fig 1B.
It can be said, therefore, that the resultant current in the neutral conductor of the distribution circuit is 9 A, which consists of0 A offundamental current for the balanced load and the contribution of the 3rd harmonic current of 3 A from each of the three line conductors. This is represented in the diagrams Fig 4(a), (b) and (c), which also show the line conductor currents and confirm that the resultant is 10.44 A, as calculated earlier.
In the absence oftriplen harmonics, and in a balanced system, no current would flow in the neutral conductor. However, where there is an imbalance in line conductor current, the temperature of the neutral conductor increases due to the additional current flow, although this would be offset by a reduction in the heat generated in one or more of the line conductors (523.6.2).
In comparison, the triplen harmonics present in the line conductor currents of a three-phase, four-wire circuit will not cancel in the neutral but will add together, as shown in Fig 3. The neutral conductor would therefore carry the current without a corresponding reduction in current flow in the line conductors, meaning an increase in temperature of the neutral conductor. This fundamentally reduces the current-carrying capacity of the neutral conductor and possibly that of the line conductors due to their close
proximity to the neutral. This would essentially mean an increase in the minimum conductor size required for the circuit.
BS 7671 identifies the requirements for triplen harmonic current and recognises the effects on current-carrying capacity and impact on the minimum required conductor size in a three-phase, four-wire circuit, including:
• the neutral conductor must be taken into account when ascertaining the current-carrying capacity of the circuit (regulation 523.6.3 and Section 5.5 of Appendix 4 of BS 7671)
• where the total harmonic distortion due to triplen harmonics is greater than 15% of the fundamental line current:
• the neutral conductor is to be considered as a loaded conductor (523.6.1)
• the neutral conductor must not be smaller than the line conductors, as is permitted in some circumstances by regulation 524.2.3 (523.6.3).
• where the total harmonic distortion due to triplen harmonics is greater than 33% of the fundamental line conductor current, an increase may be required in the cross-sectional area (csa) of the neutral conductor (524.2.2), in which case either the neutral conductor would have to have a csa greater than that of the line conductors, or the csa of all the circuit conductors would have to be chosen taking account of the current in the neutral conductor
• the heating effect of harmonic currents on the line conductors should also be taken into account (section 5.6 of Appendix 4 of BS 7671);this includes not only triplen harmonics but other additional harmonics.
Implications overcurrentonprotection
Overcurrent detection in accordance with regulation 431.2.3 must be provided for the neutral conductor where the harmonic content of the line conductor currents is such that the current in the neutral conductor might exceed the current-
carrying capacity of that conductor. Therefore, harmonic currents should be taken into account when selecting an overload protective device (533.2.2).
Implications voltageon drop
Because harmonics operate at frequencies higher than that associated with the fundamental frequency, harmonic currents increase the voltage drop in a circuit compared with the value calculated when using the tables of voltage drop in Appendix 4 of BS 7671, which typically apply to frequencies ranging from 49 to 61 Hz.
However, the increase in voltage drop is more linked with higher harmonic frequencies and for larger conductor sizes, and as an effect from an increase in inductive reactance, which is outside the scope of this article.
Summary
This article has highlighted the issue surrounding triplen harmonics and the considerations for the contractor when installing non-linear loads, typically within larger industrial/commercial type installations. Also considered was the impact oftriplen harmonics, the subsequent effects of their combined currents circulating within a neutral conductor of a three-phase, four-wire distribution system, and the effects that may significantly reduce the neutral conductors current-carrying capacity while increasing the risk of overload.
A subsequent article in Connections will consider the sizing of multicore cables and look in more detail at the guidance given in Section 5.5 of Appendix 4 of BS 7671.
This course concludes with a written paper and practical assessment that take place in simulated conditions, and a multiple-choice exam.
INSPECTIONANDTESTING INMEDICALLOCATIONS
Objective:This is the fourth article in a series looking at the requirements of Section 710 of BS7671for electrical installations in medical locations. This article in particular focuses on the requirements for inspection and testing in such medical locations.
Introduction
The first article in Issue 227 of Connections looked at the scope of Section 710, and described the system of grouping and how the system classification for safety service supplies, given in Section 560, is applied to a medical location. The second article, in Issue 228, considered the fundamentals of the medical IT system as a means to provide a reliable source of supply and the third article, in Issue 229, considered the requirements for shock protection.
This article focuses on the requirements for inspection and testing at various stages during the life cycle of the electrical installation in a medical location.
Initialverification
Verification of new work shall be made by one or more skilled persons competent in such work (641.6). This would require any such competent person(s) to have sufficient training, knowledge and experience working in medical locations to undertake the initial verification effectively and safely.
The process for the initial inspection and testing of a medical location is fundamentally no different to that required in any other installation in terms of procedural methods and the need for dates and results of each verification to be recorded.
For every new installation, addition or alteration, BS 7671 requires inspection and testing to be carried out during the construction and on its completion, before being put into
service to verify, as far as is reasonably practicable, that the requirements of BS 7671 have been met (134.2.1; 641.1).
As such, the tests described in regulations 643.2 to 643.11, where relevant and appropriate for the installation being tested, shall be carried out (643.1).
Regulation 710.514.9.1 requires that all information pertaining to the electrical installation, including records, drawings, wiring diagrams and documentation relating to any modifications for the medical location, shall be provided. The electrical contractor must therefore ensure that the results of each verification are recorded (710.641).
Inspection
The objective of the initial inspection is to verify that the installed electrical equipment (excluding ME equipment), and including wiring systems:
• complies with the requirements of Section 511 (Compliance with Standards)
• is correctly selected and erected in accordance with BS 7671 while taking account of manufacturers' instructions
• is not visibly damaged or defective in a way that would impair safety (642.2).
The inspection must precede any testing and would normally be carried out while the part of an installation under inspection is disconnected from the supply (642.1). This enables any defects to be found that might otherwise invalidate the test results obtained
or make testing of the installation dangerous to the occupants of the building or to the person(s) carrying out the testing.
Regulation 642.3 gives a list for the minimum inspection checks that should be carried out where relevant. The regulation also makes reference to the particular requirements of Part 7 of BS 7671 for special installations or locations, including those of Section 710 for medical locations, which must be taken into account during the verification process.
The specific items to be inspected for a medical location will include, for example, methods of protection against electric shock with respect to both the general requirements of Chapter 41 and the additional requirements of regulation Group 710.41, including the requirements for verification of the resistance of supplementary protective equipotential bonding conductors (710.641 (iii)).
Testing
The general requirements of Part 6 of BS 7671 apply to testing in medical locations as much as any other type of installation. The sequence of tests and how they are performed also remains the same.
As with many electrical installations, there may be a significant time interval between the initial installation of conductors and the final commissioning or handover of the installation. However, damage to installation wiring may have occurred during this time, when, for example,
Extraneous-conductive-part (theatre lamp supported by structural steel in ceiling)
Equipotential Bonding Busbar (EBB) within an enclosure
Fig 1 Testing between exposed-conductive-parts and extraneousconductive-parts in a medical location
Note: Protective equipotential bonding conductors between socket-outlets and equipment within the group 2 location have been omitted for clarity-refer to Connections article 229.
cables are plastered over and flooring and suspended ceilings are installed.
In such cases, this will necessitate repeating a test previously carried out. It is not acceptable to rely solely on test results obtained at an earlier stage of the installation process, although the results may of course be used to demonstrate where damage has occurred after the initial testing.
In addition to the general requirements of Chapter 64, regulation 710.641 requires that, both prior to commissioning and after alterations or repairs and before recommissioning, the following tests shall be carried out:
i. Complete functional tests of the insulation monitoring devices (IMD) associated with the medical IT system including insulation failure, transformer high temperature, overload, discontinuity and operation of audible/visual alarms.
ii. Measurements of no-load leakage current of circuits supplied by the
medical IT transformer, including the leakage current of the enclosure, in a Group 2 location (710.411.6 and 710.512.1.1indent (i)).
iii. Measurements to verify that the resistance of the supplementary equipotential bonding does not exceed the limits given in 710.415.2.2, such that in Group 1 and 2 medical locations:
• the resistance of protective conductors between the earth terminal of any socket-outlet or fixed equipment and any exposed-conductive-part and/or extraneous-conductive-part shall be such that the touch voltages 25V AC or60VDC are not exceeded (710.411.3.2.5), and
• The measured resistance between the earth terminal of any socket-outlet or fixed equipment and any extraneous-conductivepart shall not exceed 0.2 Q (seeFigl).
With regard to both indents (i) and (ii) of710.641, initial verification would be provided by the medical IT system supplier/installer as part of their commissioning documentation. However, with regard to indent (iii), testing should be carried out by the contractor as part of the fixed wiring installation.
As discussed previously in Issue 229 of Connections,in a TN and TT system the conventional touch voltage of 50 Vis reduced to a value of25 V AC or 60 V DC in group 1 and 2 medical locations. As such, protective equipotential bonding conductors are required to equalise the potential difference and limit the magnitude of touch voltages during a fault. Bonding conductors are used, and typically arranged in radial circuits and connected independently to the Equipotential Bonding Busbar (EBB), in conjunction with circuit protective conductors for the particular circuit, connected at the local distribution board.
Readings taken at EBB
Tablel
Type of installation
Hospitals and medical clinic Group 0 lyear locations
Hospitals and medical clinic Group 1-2 6months locations
*The requirements of regulation 710.651 must also be taken into account.
To meet the requirements of710.641 Any periodic inspection and (iii) the value of measured resistance 1 testing is subject to the requirements between the EBB and each relevant point of Chapter 65 of BS 7671, as for within the group 1 and 2 locations must any other installation (135.1 and be verified to ensure that the results 710.651). Although BS 7671 does not obtained do not exceed those stated in state which tests or the sequence for 710.415.2.2, as shown in Fig 1. testing that form part of a periodic
A schedule of test data must inspection, regulation 651.2 does state be recorded for the supplementary that the periodic inspection shall be protective equipotential bonding supplemented by appropriate testing and system. Such information, based on the measurements from Chapter 64. format given in 710.514.9.l(vii), should The person(s) responsible for the include data relating to the measured initial installation design of the medical value of resistance between connected location is required to specify the items within the patient environment, interval for the first periodic inspection. and the cross-sectional area (csa) Similarly, where an alteration or of protective equipotential bonding addition is made to an existing conductors. Due to limited space on installation, information relating to the the standard forms, this data may be subsequent periodic inspection should recorded on a separate document and be recorded in the EiC (644.4). appended to the Electrical Installation
Table 1 gives recommendations for Certificate (EiC). the interval to the first periodic inspection
Test results may be influenced of a medical location and is partially by parallel paths, it may therefore be reproduced from Table 3.2 in IET GN3. necessary to disconnect one end of the However, when making the protective conductor when performing recommendation of the interval, the the test. person compiling the EiC should take
Note: The above tests are in addition into account, amongst other things, to those required by Chapter 64 of Note 1 to regulation 710.651, which BS 7671, the supporting information recommends inspections: given in Health Technical Memorandum
a) Annually -complete functional HTM 06-01: Electrical Services Supply tests of the IMDs associated with and Distribution, and the HTM 06-02: the medical IT system, including Electrical Safety Guidance for Low insulation failure, transformer Voltage Systems, published by the high temperature, overload, Department of Health. discontinuity and operation of Equivalent guidance documents are audible/visual alarms. also available for the devolved nations
b) Annually -measurements to (710.641). verify that the resistance of
Periodicverification
the supplementary protective equipotential bonding does not
Persons undertaking the periodic exceed the limits given in regulation inspection, testing and reporting 710.415.2.2 and recorded in the in a medical location should have format given in 710.514.9.1 (vii). above-average knowledge and
c) Three-yearly-measurements of experience of working in such types leakage current of output circuits of environments to enable them to safely and of the enclosure of the medical and accurately assess the condition IT transformers in no-load condition of the existing installation. (710.512.1.1 (i)).
Maximum initial perio dbetween inspection and testing
5years
lyear*
With regard to indents (i) a the testing of such systems carried out either by the IT nd (iii), should be system manufacturer or those wit hspecific ystems. knowledge of medical IT s Note 2 to regulation 71 that supporting informatio 0.651 advises n on periodic venin randum inspection and testing is gi the Health Technical Memo 06-01: Electrical Services Supply and lhealth Distribution. Client or loca authority requirements, if any, may also apply (see Note 6 to 710.1).
Summary
Although the general requi rements have been tages for inspection and testing considered at the various s throughout the life cycle of a medical ticular, ditional location, this article in par has focused on both the ad requirements in Section 71 verification (710.641) and t 0 for initial hose for periodic inspection and te sting (710.65). ngwork cations Contractors undertaki in such types of medical lo must be competent and ha ve sufficient perienceto rkinasafe knowledge, training and ex carry out the necessary wo and effective manner.
Objective: A topic which often appears on electrical installation forums is when is it really necessary for an electrician to use insulated hand tools?
In order to answer this question it is necessary to consider the legal aspects. Anyone engaged in work activities on or near to live conductors must comply with the requirements contained within the Electricity at Work Regulations 1989 (EWR). Regulation 14, Work on or near live conductors, is reproduced below:
No person shall be engaged in any work activity on or so near any live conductor
(other than one suitably covered with insulating material so as to prevent danger) that danger may arise unless:
a) it is unreasonable in all the circumstances for it to be dead; and
b) it is reasonable in all the circumstances for him to be at work on or near it while it is live; and c) suitable precautions (including where necessary the provision of suitable
protective equipment) are taken to prevent injury.
Although this regulation clearly permits work on or near live conductors, this can only take place where all three conditions (a) and (b) and (c) above are met. Guidance on and about these conditions can be found in The Electricity at Work Regulations 1989: Guidance on Regulations (HSR25),
downloadable free of charge at hse.gov.uk/pubns/books/hsr25.htm
Most types of electrical work should not be carried out on or near live conductors. If danger may otherwise arise, the conductors should be made dead, and be proved to be so, before any work on or near them commences. Furthermore, adequate precautions; such as locking off the means of isolation and placing of notices; should be taken to prevent the conductors from becoming electrically charged during the work, if danger may thereby arise (EWR regulation 13).
Regulation 14 recognises that there are circumstances where it is unreasonable, having regard to all relevant factors, for the equipment to be dead while work proceeds. Examples of work where regulation 14 often applies include electrical testing:
• to establish whether electrical conductors are live or dead
• to establish whether the polarity of the incoming supply to an installation is correct or incorrect
• to measure earth fault loop impedance at the origin of an installation.
Working on or near live conductors should be the exception, not the normally adopted practice.
There is nothing wrong with using insulated hand tools where this is not necessary for safety, such as when working on a circuit known and proven to be dead. But if an electrician finds themselves thinking of using an insulated hand tool as a precaution against injury in connection with working on or near live conductors, they should think again. The
use ofinsulated hand tools, like any other precaution intended to prevent injury, cannot alone make it permissible to work on or near live conductors. As stated previously in this article, such work is permitted only where all three conditions (a) and (b) and (c) ofregulation 14 are satisfied.
Where insulated hand tools are to be relied on as protective equipment for the purposes of condition (c), they should meet the requirements of BS EN IEC 60900:2018 (incorporating corrigendum May 2020) Live working - Hand tools for use up to 1 000 V AC and 1 500 V DC, they shall be suitable for the work concerned and it should be confirmed prior to each use that they are free from any damage, deterioration or modification that may result in danger.
As shown in Fig 1, clause 4.1.4 of BS EN IEC 60900:2018 states that each
(insulated) hand tool shall be legibly and permanently marked with:
e the symbol IEC 60417-5216:200210 -Suitable for live working; double triangle shown in Fig 1
• the electrical working limit for alternating current, 1000 V, immediately adjacent to the double triangle symbol.
Depending on the circumstances, other protective equipment, including protective clothing, may also be required. Further guidance about protective equipment and other precautions can be found in Electricity at work: Safe working practices (HSG85), downloadable free of charge from hse.gov.uk/pubns/books/ hsg85.htm
This publication also covers the decision-making process for whether to work live or dead.
Fig 1 Symbol denoting insulated hand tools are suitable for live working; double triangle (IEC 60417-5216:2002-10)
ADDITIONSAND ALTERATIONSANDTHE AEDUIAEMENTS OF REGULATION132.16
Objective:BS7671 is written with its main focus on new electrical installation work and this frequently results in issues when trying to apply its requirements to existing installations such as when, for example, making additions and alterations to an existing installation. This article clarifies the requirements of BS7671 for alterations and additions. It also highlights the importance of carrying out a pre-assessment of the existing electrical installation prior to starting such work.
Introduction
Regulation 132.16 contains a requirement that no addition or alteration shall be made to an existing installation unless it has been ascertained that:
• the rating and condition of any existing equipment, including that of the distributor, is adequate for the altered circumstances
• the earthing and bonding arrangements of the installation, if necessary for the protective measure applied for the safety of the addition or alteration is adequate.
This requirement is often interpreted as meaning that in order to carry out an addition or alteration, the existing circuit being modified must be made to conform to all applicable requirements of BS 7671 current at the time that the modification is made. This is not the case. Whilst any defects and non-compliances in the existing installation which may detrimentally affect the safety of the addition or alteration must be remedied, any other defects or non-compliances that
are observed during the course of the work concerned with alterations or additions may remain uncorrected but must be recorded on the certification for the addition or alteration under 'Comments on the existing installation'.
132.16deconstructed
The requirement
Currently, regulation 132.16 states that:
No addition or alteration, temporary or permanent, shall be made to an existing installation, unless it has been ascertained that the rating and the condition of any existing equipment, including that of the distributor, will be adequate for the altered circumstances. Furthermore, the earthing and bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate.
Some history
The UK wiring regulations have contained requirements applicable to
additions and alterations for many years.
For example, the Eighth Edition; Regulations for the Electrical Equipment of Buildings, issued in 1924, contained the requirement, reproduced as Fig 1, calling for it to be ascertained that the existing electrical equipment of the electrical installation was suitable for the additional current demand caused by an alteration or addition.
Up until the publication of the 17th Edition (BS 7671:2008), the requirements for additions and alterations continued to state specifically that it was necessary to determine that the existing equipment, including that of the distributor, 'which will have to carry any additional load' was adequate for the altered circumstances. Although no longer stated explicitly, the fundamental requirement for sufficient capacity to supply any additional demand safely remains the key issue when an addition or alteration is made to an existing installation.
Theexistinginstallation beingaddeHtooraltered
Any defects or omissions observed in the existing installation that would affect the safety of the addition and alteration; that is, those classified as immediately dangerous (Cl), potentially dangerous (C2) or requiring further investigation (FI) during periodic inspection and testing, must be corrected before a certificate is issued. To obtain this information it is recommended that a prework assessment should be undertaken of those parts of the existing installation on which the addition or alteration is reliant for reasons of safety. In the case of any deficiencies attributed a Cl classification, measures should be taken to remove the immediate danger as soon as is possible. Assessing the suitability before starting the work is also highly advisable from a business point of view. If after starting work, for example, it becomes apparent that there is no bonding to an extraneous-conductive-part, when the customer is informed of the need for this additional work, they may disagree and argue that they have already agreed a price for the work. However if you apply due diligence before starting, and advise on the lack ofrequired bonding, an appropriate price can be agreed and work required can be suitably planned and documented.
Any other defects and noncompliances found in the existing installation during the pre-assessment or whilst undertaking the alterations or additions should be recorded on the certification covering the alteration or addition (644.1.2). There is no requirement to carry out remedial work on any such observed deficiencies. However, before an addition or alteration is carried out, the adequacy of the following must be determined in respect of any additional current demand resulting from the modifications:
The current rating of the equipment of the supplier and distributor
This would require a knowledge of the characteristics of the supply (132.2) and an assessment of the maximum
ADDITIONS TO EXISTING INSTALLATIONS
128. Care Required in Making Additions to Installations.- Before an addition is made to an installation care shall be taken to ascertain whether the existing conductors, switches, etc., affected by the addition are of sufficient capacity for the augmented current which they may have to carry.
lfote.-Alternative plug positions are often provided for electric heating appliances, and in such cases it should be ascertained whether the existing conductors are of sufficient size to allow of the simultaneous use of apparatus connected to more than one plug.
Fig 1 Extract from Regulations for the Electrical Equipment of Buildings
demand, including any additional loading introduced by the modification (311.1).If the existing capacity is found to be insufficient, the distributor should be contacted to upgrade the supply arrangement before the addition or alteration is energised.
The Energy Networks Association has published guidance on cut-out ratings for installations where it is intended to install electric vehicle charging equipment or heat pumps, which can be downloaded free of charge at energynetworks.org/ publications/cut-out-rating-guidanceto-electric-vehicles-or-heat-pumpsinstallers
The rating of any existing equipment in the final circuit(s) being modified and any distribution circuits supplying the final circuit(s)
This could include the current rating of distribution boards (536.4.202; 551.7.2), overcurrent protective devices and live conductors (Chapter 43). It could also include the earth fault loop impedance of the circuit(s) where knowledge of this is required for the protective measure(s) employed (643.7.3).
The earthing arrangements
The adequacy of the main earthing of the existing installation and of the circuit protective conductors of the distribution and final circuits associated with the modification should be established (regulation group 543.1), noting that calculating the minimum cross-sectional area (csa) using the equation given in regulation 543.1.3 will generally result in a smaller acceptable csa than applying the selection criteria described in regulation 543.1.4.
The main protective bonding
It should be noted that any existing main protective bonding conductor does not have to conform to the requirements of the edition of BS 7671 current at the time of the modification in order to be adequate. Its adequacy should be verified in the same manner as would be applied during a periodic inspection; that is, it may be considered to be adequate where the conductor has a csa of not less than 6 mm 2, it has been in place for a significant time, it shows no signs of thermal damage/ distress and it is effectively connected at both ends.
(1924)
Requirements alterationfortheoraddition
It is necessary to confirm that the electrical installation work of the addition or alteration complies with any relevant requirements of the current edition of BS 7671 and does not impair the safety of the installation (641.5).
On completion of the addition or alteration, an Electrical Installation Certificate (EIC) must be issued to the person ordering the work (644.1). Where the addition or alteration does not include the addition of one or more new circuits, or the replacement of a distribution board, a Minor Electrical Installation Works Certificate (MEIWC) may be issued instead of an EIC (644.4.201).
Examples
Best Practice Guide 4 - Electrical installation condition reporting:
Classification Codesfor domestic and similar electrical installations (BPG4) published by Electrical Safety First (E SF) includes a list of inadequacies observed during periodic inspection and testing for which the contributing organisations, including NICEIC, believe improvement is recommended (Code C3). BPG4 advises that this code indicates that whilst an observed inadequacy is not considered to be a source of immediate or potential danger, improvement would contribute to an enhancement of the safety of the electrical installation.
To paraphrase; such improvements are 'nice to have, but not essential for the safety of the electrical installation'. As such, it is not necessary to rectify
any deficiency that warranted a C3 classification code. This would include, for example:
• absence of additional protection by RCDfor:
• AC circuits supplying luminaires in domestic household premises
• cables installed at a depth ofless than 50 mm from a surface of a wall or partition where required for a particular type of cable installation
• absence of an Arc Fault Detection Device (AFDD) in:
• a Higher Risk Residential Building (HRRB)
• a House in Multiple Occupation (HMO)
• purpose-built student accommodation (halls of residence)
• care homes
• undersized csa of a main protective bonding conductor where the conductor has a csa of not less than 6 mm 2 and there is no evidence of thermal damage. Note: BPG4 recommends that this non-compliance does not require the allocation of any classification code.
Summary
Neither regulation 132.16 nor regulation 641.5 requires that a circuit being altered or added to, or any other part of the installation which may have a bearing on the safety of any such alteration or addition, must be made fully compliant with the requirements of BS 7671 before an addition or alteration is made. Because the addition or alteration is being made to an existing installation,
the requirements for periodic verification apply to any assessment of its suitability for modification. Ifthere are no observed instances of damage, deterioration, defects or conditions that warrant being classified as immediately dangerous (Cl), potentially dangerous (C2) or requiring further investigation (FI), the existing installation may be considered to be in a satisfactory condition for continued service and so suitable for modification.
It is often suggested that regulation 132.16 requires an installation to be fully compliant with the requirements of the current edition of BS 7671 before additions or alterations may be made to it. This misinterpretation can result in unnecessary cost when even the most minor additions or alterations are carried out and, in some cases, this may mean that additions or alterations that might improve the safety of the installation are not carried out. Moreover, such a misinterpretation may also mean that additions and alterations are carried out by persons that are not electrically competent. As such, it is likely that this is having a detrimental effect on electrical safety.
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REPLACING RN ELECTRICSHOWER
Objective:This article looks at the issues that may arise when it is necessary to replace an electric shower in an existing premises. It considers the assessment of the existing installation prior to work commencing, the assessment of current-carrying capacity taking into account ambient installation conditions and the selection of a suitably rated replacement unit.
Introduction
Prior to additions and alterations being made to an electrical circuit it is necessary to determine whether the installation is suitable for the alteration, as outlined in regulation 132.16. This is covered in greater depth in another article in this issue of Connections (see p54).
Thereafter, an assessment should be made to determine, so far as is reasonably practicable, the current capacity of the installed cable based on its uncorrected current rating (It) after the application of any relevant correction factors for ambient conditions such as grouping with other circuits (Cg) and presence of thermal insulation. This is necessary as the original design intentions are not known and, increasingly, any such original design considerations may have been affected by the addition of extra thermal insulation placed over the conductors.
Having determined the currentcarrying capacity for the cable in its as installed condition (Iz), a suitably rated replacement shower unit can be obtained and fitted.
Whyreverifythecircuit
Electric showers come in a variety of ratings, usually given in the unit of power; Watts, or kilowatts (kW). Generally, the available ratings are between 7.5 kW and 10.8 kW. Historically however, electric showers were only available towards the lower end of these ratings, which can lead to an incompatible shower being installed when replacing a dated shower and using a
'one size fits all' approach. This can result in overloading of the cable and circuit accessories, potentially leading to a fire hazard.
Reverificationofthecircuit
When replacing a shower, a simple verification process should be carried out to ensure the circuit is suitable for the altered load. The steps for this are detailed within this article for the following scenario:
A new electric shower is to be installed to an existing circuit. The client has supplied a 9 kW rated shower, which is to replace a faulty 7.5 kW device. The cable serving the shower is a 'twin and earth' type with 6.0 mm 2 live conductors and a 2.5 mm 2 circuit protective conductor (cpc). The circuit is protected by a 32 A circuit breaker to BS EN 60898, and a 30 mA Type AC residual current device (RCD) to BS EN 61008-1. The measured voltage at the shower position is 245 V. The most detrimental part of the cable run is through the loft, where the cable is covered by 100 mm of thermal insulation for several metres (installation method 100). The cable is not grouped with other circuits and no other rating factors apply. A 40 A double pole isolator is located outside of the bathroom.
(i) Determine the design current rating of the new shower (I.,) Shower manufacturers will declare the
power rating of their devices; the rating is generally provided at two nominal voltages, 230 V and 240 V. The different voltages yield different power ratings. This is due to the fixed resistance of a shower. An example of a rating that comes within the manufacturer's instructions is reproduced as Fig 1.
9kWshower
Fig 1 Typical shower power rating taking account of supply voltage
As the shower is a resistive load, the higher the voltage, the greater the current demand. The designer must consider the actual voltage at the point ofinstallation. The tolerance for a 230 V nominal supply is-6% + 10%, which is a range of216V to 253 V. Without prior knowledge of the voltage, the designer should assume a voltage at the upper range of the scale. When using measured values, the designer must consider that voltage varies depending on the load of the network.
An effective way to obtain the design current is to first determine the resistance of the shower as shown below:
Fig 2 Table 4D5 From BS7671:2018+A2:2022
TABLE 4D5 - 70 °C thermoplastic insulated and sheathed flat cable with protective conductor (COPPER CONDUCTORS)
JRRENT-CARRYING CAPACITY (amperes) and VOLTAGE DROP (per ampere
# For full installation method refer to Table 4A2 Installation Method 101
:# For full installation method refer to Table 4A2 Installation Method 102
I# For full installation method refer to Table 4A2 Installation Method I 03
1erepracticable, a cable is to be fixed in a position such that it will not be covered with thermal insulation.
~lation 523.9, BS 5803-5: Appendix C: Avoidance of overheating of electric cables.
!ding Regulations Approved Document B and Thermal insulation: avoiding risks, BR 262, BRE, 200 I refer.
R= V2 p R= 240V2 9000W
R=6.4Q Equationl
With the resistance known, the current can be found with the known voltage of the installation. Equation 2 determines this to be 38.28 A L _ 245V b- 6.4 Q
Ib=38.28A Equation2
If 230 V was used to determine the current of the proposed 9 kW shower, the current demand would be 35.9 A
The shower being replaced that is rated at 7.5 kW had a current demand of 31.9 A at 245 V.
(ii) Determine the current carrying capacity of the cable (I,)
To determine the current-carrying capacity of the cable (I,), the tabulated value of current (Io)is first required, this is then adjusted due to any correction factors that may apply to the circuit.
Appendix 4 of BS 7671 contains tabulated values of current-carrying capacity, and the correction factors that may be applied to these values.
Table 4D5 from BS 7671, reproduced as Fig 2 gives current-carrying capacities for PVC insulated and sheathed flat 'twin/ three-core and earth' type cables.
From Fig 2, the tabulated current rating (Io)ofinsulated and sheathed flat cable having 6.0 mm2 live conductors using Method 100 is 34 A. To determine the cable's current carrying capacity (I,), the relevant correction factors shall be applied to this value, although as there are no correction factors to apply for this scenario, Iz equals I,.
I.=I,x Cax c.x C;
J.=J,xlxlxl.
I.=I,
I.=34A Equation3
(iii) Ensure coordination between the load (It,),the protective device (I.) and the cable (I,).
The requirements ofindents (i) and (ii) ofregulation 433.1.1, which is condensed into the expression shown below, shall be met to ensure the cable is suitably protected against overload.
Ib sI. sI. Formula2
Where:
lb = design current
In= Current rating of protective device
Iz = Cable current carrying capacity
The values from the scenario can now be input to the expression, as shown below.
IbsI.sI.
38.28 A 2: 32A s 34A
Equation4
The existing circuit-breaker and cable are not suitable for the proposed load. Equation 4 shows the load current is greater than the protective device and the cable rating.
Regulation 433.1 states:
Every circuit shall be designed so that a small overload of long duration is unlikely to occur.
If the proposed shower was installed to this circuit, the cable will be subject to overload. Furthermore, the protective device would take a long time to trip under this overload condition. Over time this persistent overload could potentially damage the cable, isolator, circuit-breaker and shower, leading to a potential fire hazard.
To satisfy the requirements of BS 7671, circuit upgrades will be required to accommodate the new shower. Alternatively the client may decide to replace the shower with one of the same rating or lower.
Using the power rating of the existing faulty 7.5 kW shower, the requirements of BS 7671 are met.
31.9As32A s34A Equations
A simple method to determine the maximum power rating of the replacement electric shower, without the need to upgrade the circuit, is to multiply the circuit-breaker rating by the phase voltage as shown in Equation 5.
Max shower rating = I. X UPhase
7,840 W =32A x 245 V
7.8kW
Equation6
It may not always be the case that the existing circuit satisfies BS 7671. It is possible the existing circuit may be found to be non-compliant. A common example of this is where an additional layer of thermal insulation has been installed within the loft, further covering the cable. This can change the installation method from 100 to 101, which reduces the current carrying capacity of the cable by approximately 20%.
Furtherverification
The article, up to this point, has focused on ensuring that the current-carrying capacity of the circuit is suitable for the new load. Further checks are required to ensure that the circuit is in a satisfactory condition for continued use.
Further checks include inspections of the existing circuit to ensure it has been operating correctly with the existing shower. These inspections would include checking the circuit-breaker, circuit accessories and cable terminations for signs of thermal damage.
Testing will supplement these inspections to ensure the requirements of automatic disconnection of supply and additional protection are met. Voltage drop verification for long circuits should also be considered.
Summary
When replacing an electric shower, the person responsible for undertaking the proposed work should ensure that the existing circuit meets the necessary requirements of BS 7671 before making an addition or alteration, and in particular, that the circuit has sufficient capacity for the proposed replacement shower. The current demand of an electric shower is proportional to the voltage of the installation and this is something that should not be overlooked, as it may be the difference between a compliant and non-compliant design. Additionally, the inspector may find during checks that the circuit is not suitable for the existing load. This can be due to energy efficiency measures that have been carried out after the original installation, such as the installation of additional loft insulation.
In the following multiple-choice questions you should choose one of the four options that, in your opinion, is the correct answer. You may find it useful to refer to the technical articles in this issue of Connections and BS 7671:2018+A2:2022. The answers to the questions, accompanied by a briefrationale, can be found at the end of the technical section.
1. Which one of the following harmonics would have the least impact within a three-phase installation?
a) 3rdorder
b) 6thorder
c) 9thorder
d) 15th order.
2. What name is often given to harmonics which intersect the zero point of all three phases on a waveform?
a) Zero sequence
b) First sequence
c) Second sequence d) Third sequence.
3. A circuit has been monitored using a power quality analyser which only indicates the presence of a 3rd harmonic.
Identify the value of the 3rd harmonic current where the circuit's fundamental current is 27 A and the value ofrms current is given as 27.27A.
a) 1.8A
b) 2.8A
c) 3.8A
d) 4.8A.
4. During the initial verification the measurements of no-load leakage current of the output circuits and that of the enclosure, supplied by the medical IT transformer may be obtained from which one of the following?
a) The medical IT system supplier/ installer
b) The electrical contractor/installer
c) The local health authority
d) The designer of the electrical installation.
5. When completing an Electrical Installation Certificate, what is the recommended frequency between measurements ofleakage current of the medical IT system during any subsequent periodic inspection and testing?
a) Yearly
b) Everytwoyears
c) Every three years
d) Every five years.
6. When undertaking the complete functional testing of insulation monitoring devices associated with medical IT system as part of a periodic inspection and test, which one of the following options does not form part of the additional requirements of regulation 710.651?
a) Transformer high temperature
b) Overload
c) Insulation failure
d) Connection of conductors.
7. Which of the following standards contains requirements for hand tools for use up to 1000 V AC or 1500 V DC?
a) BS IEC 61557-3
b) IEC60417
c) BS EN IEC 60900
d) BSEN61010-1.
8. When is it acceptable to carry out work on or near alive conductor?
a) Where it is unreasonable in all the circumstances for it to be made dead
b) Where it is reasonable in all the circumstances for work to be carried out on or near it while it is live
c) Where suitable precautions, including provision of suitable protective equipment, are taken to prevent injury
d) Where all of the three options above are met.
9. When completing the certification for an addition or alteration, which of the following should be recorded?
a) The classification code for any observed non-compliances revealed during the inspection carried out prior to work commencing
b) Any defects found within the existing installation
c) The measures required to make the addition or alteration fully compliant withBS7671
d) Any defects or omissions that will affect the safety of the addition or alteration.
10. From which organisation can guidancebesoughtregardingthe rating of service cut-outs when intending to install electric vehicle charging points or heat pumps?
a) Health and Safety Executive
b) Institution of Engineering and Technology
c) Energy Networks Association
d) Local Authority Building Control.
11. Which of the following characteristics relating to an electric shower unit has a fixed value?
a) Resistance
b) Current
c) Voltage
d) Power.
12. The installation method to be applied where a 70 °C thermoplastic insulated and sheathed flat cable with protective conductor installed above a plasterboard ceiling covered by thermal insulation exceedingl00 mm in thickness is:
a) 100
b) 101
c) 102
d) 103.
1. b) Even harmonics of the 6th order would generally cancel out and have less impact on theinstallation.
2. a) Harmonics that cross the zero point of all three phases on a waveform are referred to as'zero sequence'.
3. c) Irms = /Il1+Ils27.27 =/27 2 + Il3
2 = 27 2 +Ils
2 - 27 2 =Ils
4. a) The measurements for no-load leakage current of circuits supplied via the medicalIT transformer, including that of the enclosure would normally be provided in the documentation supplied by the medical IT system supplier or installer.
5. c) Measurements ofleakage current of output circuits and of the enclosure of the medical IT 710.651(iii) transformer shall be taken every three years.
6. d) The connection of conductors would form part of the verification under the general
requirements of Chapter 64.
7. c) BS EN IEC 60900:2018 (incorporating corrigendum May 2020) Live working - Hand tools foruse up to 1 000 V AC and 1500 V DC.
8. d) Regulation 14 of the Electricity at Work Regulations 1989 states that conditions a), b) and c) EWR1989 must be met before live working is permitted.
9. b) For an addition or alteration The person responsible for the new work, or a person
644.1.2 authorised to act on their behalf, shall record on the Electrical Installation Certificate or the Minor Electrical Installation Works Certificate, any defects found, so far as is reasonably practicable, in the existing installation.
10. c) The Energy Networks Association (ENA), www.energynetworks.org/publications/cut-out-rating-guidance-to-electric-vehicles-or-heat-pumps-installers
11. a) The resistance of the shower unit has a fixed value. All three other alternatives vary. -
by NICEICInsurance Services protects your livelihood.
DFFGAi
WINDMILLS RAE BACKINFASHION
PubQuizquestion:what'stheoldestknowndevice thatusedwindenergy?Answer:Greece'scenturiesoldwindmills.Sowhynotretrofitthemasmini powerplants?That'swhatstudentsatKonstanz UniversityofAppliedSciences,Germany,aredoing. ThroughtheSailwind4project,hundredsofthese windmillsthatoncemilledgrainnowsporthightechsailsandtheirshaftishookedupto a power generator.Fromawindforceof14m/s,arevamped millshouldgenerate5kilowattpeakofelectricity. Whatifitcouldalsobecombinedwithphotovoltaics andabatterystoragesystem?
FROMTHE GROUND UP
Bifacial solar panels have been around since the 1970s. These are the ones that absorb sunlight from both sides, generating more power than one-sided panels. So why not make the most of the underside, with a reflective surface? A shiny sheet on the ground directly under the panel bounces more light onto it.
Researchers at the University of Ottawa with National Renewable Energy Laboratory found that this boosted energy output by 4.45%. That would reduce the need for so many panels, making solar energy easier to generate in dense cities, where space is at a premium.
ANDTHEBEAT GOESONANDON ANDONANDON...
Noise-cancelling headphones are all the rage, but like many modern devices, the hassle is in the charging. Now, a clever strip of material has solved that for Urbanista's new Los Angeles headphones. Created by Exeger, Powerfoyle is a solar cell material, which, as Wired reports, "can derive energy from any type oflight, from sunshine to the lightbulbs in your home". The strip lies alongthe outside of the headband and is always drawing energy, even when the headphones are turned off, making charging (almost) a thing of the past.
