Torque Talk

[pc1966]

I do this ALOT and I know it makes using a torque driver a bit pointless but its just the way I'm wired

Why not just go over a 2nd time with the torque driver?

That is what I tend to do as it helps avoid missing a fastener that was just done up lightly when assembling things and also allows for a bit of settlement. I guess it is also partly memory from mechanical devices where you do a set of fasteners up in different torque stages to avoid warping an assembly, etc.

 

[Marvo]

Wheel nuts and electrical terminals are different situations.

The torque value for the wheel nuts is set knowing exactly what is being fitted, what its made of etc etc.

Electrical terminals could have a range of types and sizes of conductor put in them, there may even be multiple conductors in there. I can't see how one universal torque setting can be correct for all sizes and types of conductor.

Here where I am the local regs limit the number of wires in any terminal or termination to two unless it was specifically designed to accept more. Do the UK regs allow multiple wires in a single termination point?

 

[davesparks]

Here where I am the local regs limit the number of wires in any terminal or termination to two unless it was specifically designed to accept more. Do the UK regs allow multiple wires in a single termination point?

Yes they do, there is technically no limit in the regulations. However common sense, good judgement and manufacturers instructions do need to be used.

On a standard ring final circuit in the UK you can expect up to 3 conductors in a terminal, the 2 legs of the ring and a spur.

Then there's split concentric cable where the neutral is made up of a dozen or so seperately insulated conductors which all get put together in the same terminal.

 

[littlespark]

You can bet the powers that be are taking notes…

“Hmmm. Limit each terminal to 3 conductors….?”

“So, new circuit… you can’t use maybe an existing spare mcb?”

“No no… has to be a new type breaker….. with um… new din rail type.. so new circuit means new board!”

Mr Hager: “sounds good to me”

 

[billyblade]

Just thought I'd throw in a few points here. Only skimmed the thread but hopefully, my input might help.

• Every torque screwdriver is sold with a calibration certificate. The standard they are manufactured to states that they should be calibrated every 12 months or 5000 clicks (whichever comes first). The first calibration should be carried out 12 months after first use. For the purposes of the standard, first use is taken as day of purchase so can be carried out 12 months from the date on the purchase invoice rather than the date on the supplied certificate.
• Yes, you should wind torque tools down to the minimum setting when not being used. This releases the tension on the spring and reduces the chances of it drifting out of range.
• A lot of breaker manufacturers are making the holes in their plastic casings too small to get the correct screwdriver down. Installers then resort to using the next size down and this is where breakages can occur., If you don't have a good fit between screwdriver bit/blade and screw recess then all the turning forces are concentrated on one or two surfaces instead of the multiple ones intended. In the case of the +/- blades you can actually get them 90 degrees out if you use one too small and that will almost inevitably cause breakage.
• A lot of breaker manufacturers are using poor quality screws where the fit is not good. This can cause blade breakage/ camming out/ screw damage etc.
• Some of the screws used look like they are intended for a +/- blade/bit but they are actually more suited to PZ or PH. If you have broken +/- blades in the past then try PZ or PH, see if they are a better fit in the screw. They tend to 'enter' the screw recess further than the +/- blades/bits.

 

[Dustydazzler]

blimey

I have had both my vde torque drivers for well over 4-5 years and neither have been re-calibrated yet

 

[DPG]

blimey

I have had both my vde torque drivers for well over 4-5 years and neither have been re-calibrated yet

Just think of all those terminations that might be done up to precisely the wrong torque!

 

[Dustydazzler]

Just think of all those terminations that might be done up to precisely the wrong torque!

Good job I check with my manual screwdriver after torquing

 

[mainline]

“So, new circuit… you can’t use maybe an existing spare mcb?”

Single conductor from mcb to a multi join. ?

 

[Other_Tucker]

I've invented a torque wrist calibrator, a small box with 10 screws on it each one lights up at the labelled torque. We can then verify our own hand power settings every morning.