Do I need a torque screwdriver set?

[littlespark]

They put the torque setting on a sticker inside the CU usually. It must be there for a reason.
Not hidden away in the paperwork somewhere.

They may need to change the “ensure all connections are tight” label to something that mentions torque… that might bring more people into using them.

The only people that should be inside a CU are electricians, and if they all have a torque driver, then there will be no excuse for too loose or too tight connections.
Can it become a “service” like vehicles where we check that terminations are still torqued to the correct value… and CU’s sealed like a meter to detect tampering?

Random thoughts for a Friday night

 

[Dustydazzler]

Which then begs the question , Do you re-torque every 5 or 10 years when doing the Eicr or once torqued up initially is that good enough for the life of the unit ?

 

[littlespark]

Which then begs the question , Do you re-torque every 5 or 10 years when doing the Eicr or once torqued up initially is that good enough for the life of the unit ?

It would have to be checked frequently, as we all know, screw terminals can loosen simply with high load cycling as well as physical vibration.


Just trying to drum up some business for us guys

 

[Dustydazzler]

It would have to be checked frequently, as we all know, screw terminals can loosen simply with high load cycling as well as physical vibration.


Just trying to drum up some business for us guys

Re-torque annually ?

 

[littlespark]

Re-torque annually ?

Bi-annually.

Every 6 months, with a calibrated torque driver.
Just the CU terminations. More paperwork, with a list of every screw…. Serial numbers,
Optimum settings….


Most CUs start falling apart after taking the cover screws off twice, never mind for the lifetime of the equipment.

 

[telectrix]

think this thread has been torqued about enough now. mods please close with a zipper tightened to 5Nm ( weird measurement as Newton died long before the metric system was invented by the french rabble who'd just chopped the heads off all the intelligensa.

 

[LewisM]

Make all connections like hi loks that we use in aviation that snap off at a certain torque, can't be under or over tightened

 

[Dustydazzler]

Make all connections like hi loks that we use in aviation that snap off at a certain torque, can't be under or over tightened

How would you disconnect to do periodic testing ?

 

[LewisM]

How would you disconnect to do periodic testing ?

I was only messing would never work as you say for testing etc and knowing my luck I'd put the wrong cable In the wrong breaker then it would be too late

 

[Mike Johnson]

Always makes me smile when the comments turn to the whole family died in a fire caused by not conforming to ....................whatever, if the family died I would think the house was a right off and the consumer unit and electric circuits/cables destroyed along with the house, how is anyone going to know if anything conformed or was complied with prior to the fire or who is too blame, fire investigations officer's can only go so far, and I don't think they are clairvoyant.

 

[MJPD29]

Always makes me smile when the comments turn to the whole family died in a fire caused by not conforming to ....................whatever, if the family died I would think the house was a right off and the consumer unit and electric circuits/cables destroyed along with the house, how is anyone going to know if anything conformed or was complied with prior to the fire or who is too blame, fire investigations officer's can only go so far, and I don't think they are clairvoyant.

How dare you Micheal. They all died because I didn't have a torque screwdriver

 

[Mike Johnson]

How dare you Micheal. They all died because I didn't have a torque screwdriver

I humbly apologise and vow to throw myself on my sword the next time it leaves its scabbard, I have to warn you though that the last time I tried I missed.

 

[Mike Johnson]

Certainly for the most critical ones for cylinder head, etc.

While using a torque wrench to get predictable forces is better than nothing it is not really that accurate. The wrench might be something like +/-3% in terms of torque applied, but that variability of friction on the threads and surface of the fasteners can make the resulting preload up to +/-30% variability.

With angle-tightening you take up the free play and then use the geometry of the thread to stretch/compress by a certain length which relates to the desired preload, though I believe it really only works well on long (w.r.t diameter) fasteners (like cylinder head studs, etc).

The 'feel' of tightening is another method that has been automated to get better results than torque, etc. For anyone who is interested here is a brief guide:

Methods of Tightening Threaded Fasteners

Most of the boxer air cooled engines have very long studs from the crankcase through the cylinders and cylinder heads, the ones I have torqued had very necked areas in their length, designed to stretch at a set torque and pre-tention the cylinders and heads to each other.

Wow that brings back memories it was over forty years ago.

 

[telectrix]

Always makes me smile when the comments turn to the whole family died in a fire caused by not conforming to ....................whatever, if the family died I would think the house was a right off and the consumer unit and electric circuits/cables destroyed along with the house, how is anyone going to know if anything conformed or was complied with prior to the fire or who is too blame, fire investigations officer's can only go so far, and I don't think they are clairvoyant.

Fire Service have an alternative cause for "Don't Know". it's called "electrical fault".

 

[Dustydazzler]

In the old days when loads of people smoked , most house fires seemed to be put down to someone falling a sleep with a lighted smoke in their hand...

Now it seems to be because the electrician didn't use a torque wrench

 

[PEG]

Might i recommend that all the terminals that require a specific torque,be replaced by either a crimp,or soldering.....because we never have any fallings out,over those methods

 

[pc1966]

Might i recommend that all the terminals that require a specific torque,be replaced by either a crimp,or soldering.....because we never have any fallings out,over those methods

I'm surprised that spring-loaded arrangements like the Wagos have not made it to CUs yet. Would avoid a lot of these issues by design!