Torque screwdrivers

[Guitarist]

So, boys and girls, I know this was done a while back but how are you all getting on with your torque screwdrivers? Worth buying to "comply with manufacturers instructions" or not?

 

[Adam W]

I don't know about anyone else, but I certainly don't bother. I just do the screws up 'tight but not too tight'.

 

[TAZMAN]

Hi times are a changing and the anti tamper screw as i call it as been around for a while.Such budding amater sparks and landlords that take short cuts that create problems for us skilled folk .These screws stop people buggering around and burning there property down or at least putting them selves in hospital.

 

[joe j]

I don't know about anyone else, but I certainly don't bother. I just do the screws up 'tight but not too tight'.

is this just a money making scam? What you say Adam has been good for years. If I have to buy a set and get them calibrated and then get them checked on a torque checkbox every month I'm not going to risk damaging them or having them nicked I'm just going to keep them in a safe place until the next inspection.

 

[Geordie Spark]

is this just a money making scam? What you say Adam has been good for years. If I have to buy a set and get them calibrated and then get them checked on a torque checkbox every month I'm not going to risk damaging them or having them nicked I'm just going to keep them in a safe place until the next inspection.

Aye ..... a bit like some folk who take the catalitic converter off their cars after the MOT inspection.

 

[MarkieSparkie]

Inserting copper conductors into (mainly) brass terminals and tighten them to the specified torque as prescribed by the manufacturer with a calibrated torque screwdriver seems all very well when taken at face value.
However, in the real world, multi-stranded copper conductors suffer mechanical 'creep' of the connections due to the way they 'settle' after the individual conductors of a cable core have been displaced and compressed by the initial tightening action. When this is coupled with the changes of both ambient temperature and the final operating temperature of the circuit due to electrical loading, these combined stresses cause changes in ‘tightness’ over time due to the temperature coefficients of expansion of the differing metals. I think I can confidently predict that you would expect to detect a change in the 'tightness' of the connections by the re-application of your calibrated torque screwdriver after a week or more of in-service use.
Treating the domestic consumer unit as a piece of mission-critical kit is impracticable, how many home owners are going to pay for the regular torque setting of the terminals? Once every 10 years is not going to solve the problem … Mission critical systems rely on pre-planned, short duration, periodic maintenance … Try selling that to your customers!
If the authorities believe loose terminals are a real problem in domestic installations and the electrical fire statistics suggest this to be a major factor, they will have to introduce annual statutory electrical safety checks.

 

[telectrix]

torque drivers for terminals? it's gone mad. wouldn't trust one as far as i could throw it.

 

[kingeri]

TBH, this has totally passed me by. It's pretty ludicrous if you ask me. Guitarist, do you use one?

 

[telectrix]

i've got a mechanics torque wrench, goes up to 200ft.lbs. have to make an adaptor to take a driver blade. no -one will undo the buggers then. oh, sod it: it's not VDE.

:28:

 

[Guitarist]

TBH, this has totally passed me by. It's pretty ludicrous if you ask me. Guitarist, do you use one?

I don't mate. Been considering it, what with all the "follow manufacturers instructions" debates going around. I have been tightening screws since 1986 and have a pretty good feel for what is needed (after shearing off my fair share over the years). I'm not saying that I am better than a torque screwdriver, but we all know how copper moves once current flows through it, and it worries me that after a few years my "torqued" connection will become a little loose.
I have a feeling , however, that this is going to become one of those issues that doesn't go away.

 

[kingeri]

Screw terminals by their very nature will always have the potential to work loose, although in reality most loose connections I have come across on my travels were (I believe) down to not being tightened properly in the first place. I just can't see changing the tool we use to tighten terminals will have a huge impact. You either do it properly or you don't. The only real solution I see is to replace screw terminals with something else, apparently this works for maintenance free JBs so maybe those kind of terminals could be used elsewhere. Or maybe not lol.

 

[telectrix]

enter the wago MCB.

 

[Mark_Burgess]

enter the wago MCB.

I do hope so!!

 

[Mark_Burgess]

However, in the real world, multi-stranded copper conductors suffer mechanical 'creep' of the connections due to the way they 'settle' after the individual conductors of a cable core have been displaced and compressed by the initial tightening action. When this is coupled with the changes of both ambient temperature and the final operating temperature of the circuit due to electrical loading, these combined stresses cause changes in ‘tightness’ over time due to the temperature coefficients of expansion of the differing metals. I think I can confidently predict that you would expect to detect a change in the 'tightness' of the connections by the re-application of your calibrated torque screwdriver after a week or more of in-service use.
Treating the domestic consumer unit as a piece of mission-critical kit is impracticable, how many home owners are going to pay for the regular torque setting of the terminals?

I was at the southern tool fair last weekend and Whia were there, one of the guys on the stand tried to sell me one, stating the manufacturers instructions etc.
I pretty much said what Markisparkie said above to the guy, do you want to know his response was?
He just shrugged his shoulders, didn't know what to say. At that point my feet took over and made me buy stuff from Bosch!!

 

[Guitarist]

Of course he shrugged his shoulders....probably never even used a screwdriver himself.