How do you tighten your electrical connections?

Wanging it up as far as it would go was the way I used to do – at least on my motorcycles when I raced them many moons ago. That is, until a con-rod bolt failed at high revs, wrecking the engine, then me and then the bike in (very) quick, exciting and expensive succession. Falling off at 240 km/hour is quite thrilling but not recommended. I had failed to torque the con-rod bolts…

 

…now I know better.

 

And equally dangerous things can occur if electrical connections are not properly torqued. 

 

In any electrical circuit, vibration, fatigue and age can cause electrical connection loosening. All electrical connections tend to fail over time. If not found, repaired or re-tightened, this can lead to faults. A loose or corroded connection overheats or even arcs, whereas over tightening can cause the bolt or screw to break conductor strands, cut the wire and damage the connection. 

 

So over- and under-torqueing, one of which invariably happens to some extent when tightening is done by hand, are both potentially risky. Studies have indicated that while electrical installers are slightly more likely to over-tighten connections than non-electricians, they are no better at achieving a proper connection than somebody having no experience as an electrician. 

 

Additionally, some insurance companies now recognise the importance of torqueing, and whether or not this is carried out is now an early question in the event of a claim. 

 

While most manufacturers do specify torque settings for important fasteners, until recently at least, few have published these with their electrical equipment. If a torque is specified, it should be adhered to. For all these reasons, BS7671:2008 (First Amendment) Regulations 134.1.1 and 510.2 now require electrical equipment to be installed in accordance with manufacturers’ instructions. So now all connections must be checked for correct torque settings at, for example, consumer units. 

 

While torque screwdrivers have been around for some time, it still seems likely that very few electricians use them. Some will have used a torque wrench on larger conductors, such as those found on low voltage transformers or switchboards, but not torque screwdrivers for branch circuit connections. This must change because legislation, insurers and safety concerns increasingly demand it.

 

Of course, a torque screwdriver is another (quite small) cost, but a little extra cost now can save a great deal money and worry - and possibly legal action - if a fire occurs because of an incorrectly tightened connection.

 

…so torque it up…how many of you do so already? I’d like to know.