TIME TO TORQUE?
WAGO 221 Series lever connectors are integrated into the wiring centre
Torque screwdrivers may not be popular with all, but they are likely to increasingly become a mandatory requirement in the future. WAGOâ€™s David Draper explains why thereâ€™s perhaps never been a better time to take the screw out of the equation altogether.
anufacturers of installer products such as consumer units, RCBOs and MCBs are increasingly incorporating torque specifications in their installations, requiring the use of a torque screwdriver. These specifications are not just advisory. In fact, where any product specifies torque settings for screws, the use of a torque screwdriver is a statutory requirement under BS 7671 (134.1.1 & 510.3). However, despite widespread use of torque screwdrivers in industrial applications, many domestic and commercial installers still prefer to use conventional screwdrivers, gauging the torque of each screw using their own experience and intuition, as well as their own wrists. That approach looks likely to have to change soon as more products start to incorporate torque specifications, and assessors vigilantly enforce the law. Furthermore, in the event of a fault and a damages claim, insurance companies are increasingly asking for evidence that a torque screwdriver was used in the installation and may refuse to pay out if this cannot be proven. This alone is surely a good reason to start using one.
Careless torque costs lives Some installers still have their misgivings, not least about the cost of having to purchase and regularly recalibrate an additional tool. Experienced installers, who may have thousands of successful manual installations under their belts, might see no reason to change a method that has, as far as they know, always worked for them. Unfortunately, for any installers who are reluctant to make the switch from manual to torque, it seems that the increasing adoption of torque screwdrivers is inevitable, and more and more products in the future will require them for BS 7671 compliance. There is, however, a way of side stepping the whole manual versus torque screwdriver debate. And for installers who do not want to use a torque screwdriver, but do want to stay within the regulations, there has arguably never been a better time to do so.
Put a spring in your spec Spring pressure connection dispenses with screws altogether, and instead uses a clamping mechanism to constantly apply the optimum level of pressure to keep conductors secure without damaging them, taking the risk of under or overtightening completely out of the equation. They also
have several other advantages over screws. With no screwdriver required they are far quicker to install, reducing installation time by up to 50%, while also being much easier on the wrist. This can make wiring jobs safer, with less time spent working at height or in difficult to reach areas and confined spaces. In the installer industry, time is money, and the ability to wire up more jobs in less time ultimately means that more invoices can be raised. It can also free up skilled personnel to work on more complex wiring tasks.
Reduced maintenance Whilst spring pressure connectors typically have a higher unit cost compared to traditional screw terminals, this is far outweighed by the savings resulting from their reduced installation time and superior reliability. The design used by reputable manufacturers ensures that connectors have stronger resistance against overcurrent, vibration and shock compared to screws. Spring connections are also immune to loosening over time and do not require regular retightening like a screw connection would, making them free from maintenance for the life of the installation, further reducing time and costs in the future.
48 | January 2019
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