THE FIRST 100 YEARS As Crabtree celebrates its 100th anniversary, ECN takes a look back at the company’s rich history and explores many of the most significant innovations it has developed along the way.
lectrical safety has always been at the heart of everything Crabtree does. It’s a philosophy that has seen the brand through periods of depression, a world war, and market uncertainty. It enables them to consistently deliver products and devices that installers can trust, and it all started with a ‘dolly’. One hundred years ago, John Ashworth Crabtree designed a quick make and quick break switch, which safely managed electric arcs that can occur in switching devices. Patenting his creation, John went into business for himself opening a factory in Walsall, a market town in the West Midlands. 100 years later, and Crabtree remains at the forefront of electrical safety, this time with digital technology in arc fault detection devices. Crabtree AFDDs automatically detect and disconnect arc faults and prevent fires occurring in electrical cables and final circuits, providing higher levels of safety for homes and workplaces. In 1939, Crabtree (a then 20-yearold business) switched production in response to a need for the Air Ministry, which required robust, reliable, flexible, quick and easy to install aircraft wiring systems. It was Crabtree that designed and developed solder free, screw-less crimped terminals, providing safe reliable connections and safer flying conditions. Hardly surprising then that even now Crabtree uses screw-less plug-in systems in consumer units to provide instant guaranteed reliable connections in household installations in the UK. We’re now on the 18th Edition of the wiring regulations, but back when the
A look at Crabtree’s Motto Plaque
A view inside Crabtree’s machine shop at Lincoln Works
12th Edition of the wiring regulations was being published in 1950, Crabtree had been operating for over 30 years. It had launched during that time a number of innovations, including one still used today – British Standard 13A twin sockets. Now a staple in homes and businesses across the UK, British Standard 13A twin sockets were first introduced by Crabtree in 1947, one year after being awarded a Royal Warrant as a supplier of electrical products to King George VI. 13A sockets might now seem ordinary, but they make our use of electricity safer. The secret to safety is the shutter system that makes BS sockets safer to use by protecting people from accessing live parts and by using switches that contain electric arcs within protective shields. Sockets have changed over the years, through updates in decorative plates and the styles of the eras. The latest versions (Instinct) from Crabtree now combine recent innovations too, such as the multi pin shutter safety system, and full contact cable terminations, all combined with slim plates, soft curves and smooth style – because looks matter too. Heading back to the mid-century, in 1956, Crabtree introduced its first earth leakage circuit breaker, the E.60 range. Earth leakage circuit breakers (or RCDs as we now know them) are standard products these days, but they were new in the 1950s when Crabtree developed this technology for devices that protect people from risks of electric shock. Fast forward 60-odd years to the very latest earth leakage devices and you will find innovative ‘A Class’ miniature RCBOs that include twopole switching as standard for even higher levels of personal protection. In another recent drive for safety, when fires in plastic consumer units in residential properties were rising and London Fire Brigade called for action, Crabtree investigated the initial proposals and found that an alternative solution (metal enclosures) would provide a better way to control the spread of any fire that occurred in switchgear assemblies. This led directly to a change in the UK wiring regulations and now metal consumer units are mandatory. When it launched in 1919, Crabtree had a motto: “That which is built soundly endures well.” It was inscribed into the company plaque and rightly so. Crabtree was built soundly enough to provide 100 years of electrical safety to its customers. And with a 100-year solid foundation, what else can the brand do in the years to come?
RECENT INNOVATIONS AFDDs Crabtree has launched a range of AFDDs (Arc Fault Detection Devices) that fit into any new or existing installation with a Starbreaker consumer unit. Detecting arc faults that cannot be detected by RCDs or MCBs. These new devices use digital technology to provide additional protection against fires caused by arcs in AC 230V final circuits. Crabtree AFDDs constantly monitor and analyse electrical values and look for any divergence from normal patterns i.e. divergences that denote a potentially dangerous arc. They are designed and tested to not respond to arcing under normal operation of equipment, whilst simultaneously continuing to respond to arc faults whilst the equipment is being used.
RCBOs One of the key innovations with the new RCBO is that ‘miniature means miniature’. The RCBOs measure one single module wide and are just 90mm in height. This gives installers around 30% more wiring space to work with in the consumer unit, saving time on tricky installations. The RCBO will do more than just offer more space though. Its other unique innovation is that it has built in switched neutral as standard. The technology means that live and neutral conductors do not have to be disconnected for insulation resistance testing, a major benefit for contractors working with social landlords and testing in void properties, saving them time and money.
12 | January 2019
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