To torque or not to torque that is z question

[Dustydazzler]

so I need to add 1 mcb to a rather old existing mem consumers unit

I have managed to source the mcb via ‘cough’ eBay ‘cough’

But it doesn’t have the manufacture spec installation instructions manual for correct torque

Should I..
A , contact mem helpline for further information
B , wing it and guess the required torque
C , just use a normal Phillips screwdriver and let my wrist do the torquing

Thought ?

 

[Pete999]

So if you cant find the torque setting are you telling me you wouldnt be able to tighten it up and would have to ask for help

No I'm not I would use my experience to see how tight the connections were, before boil in the bag Electricians and torque drivers were even thought of.

 

[Mike Johnson]

Some of the Hager MCB's are a cable push in fit, no screws.

 

[Vortigern]

Couple of thoughts. One, never seen DNO using torque anything, just T hex and doing things tight!! You know when you tighten up, you need to wait and go back and may tighten again as the copper relaxes? Well with a torque you can definitely tighten quite a lot more. So clearly I have been over tightening (is there such a word?) for forty years. Although I have read and been told this can lead to catastrophic things (not totally sure what!) funny thing is, never happened over all that time. Agree with @The Ghost that MK sockets feel far too loose by their torque level. There is a lot more to terminating than torque alone. Such as dressing the cable and using 19 instead of 7 Strand for terminals etc.

 

[Megawatt]

There is some truth in your statement DW but far to controversial to post my reply

Pete we have to start torquing all terminations in the panel to the recommendation of the manufacturers speciations. It’s in the 2020 NEC edition which will be inspected by code enforcement

 

[KennyKen]

How many times a week do the screw drivers get calibrated? can’t imagine them being accurate.

 

[pirate]

Interesting discussion, this.
If a torque screwdriver has to be calibrated, is this an annual thing?
Kenny Ken has a point.
If the driver is used once a week, for a CU change say, that's one situation...but if you do 5 a week, should the driver be calibrated more often?
I see a difference between "mechanical" calibration and "electronic" calibration of a MFT. The former has a mechanical wear and tear element that may not be applicable to a MFT?
I expect that most of you will know just how tight is right...and i am willing to bet that even if the driver tells you it's right, if you are in any doubt you will resort to just manually checking anyway?
Maybe you all tighten the terminals, tidy up, then give them all a wee further tighten before you go home?
Better tight than slack?

No point in exhibiting a test certificate if patently the terminals are too loose, imho...the buck stops with you regardless.

 

[Moley]

I know it's not quite the same thing but we have to torque up the hv/lv connections on gen transformers and our torque wrenches have to be calibrated once a year. One thing you have to remember is to set it back to zero after use. If you don't it weakens the mechinism and it will fail its next calibration.

 

[Mike Johnson]

Most torque wrench's work on a calibrated spring so it makes sense to store them at a zero setting so the spring is uncompressed.

 

[ipf]

Much more about this and I'll be tempted to change to Torque Torque for me mobile provider...…..