torque limiting screw drivers ?

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electricaldoc

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I have had several residential electricians tell me that inspectors have asked for their torque limiting screw driver, or they will not pass inspection. One even told me of inspector telling him use the money you made to buy you a torque limiting screw drive or if I inspect you again it will be rejected.

I work in industrial environment so do not come across inspectors a lot. Is this true or is guys? exaggerating? Is torque limiting screw driver this important in residential? I plan to start doing some residential on side, and would like to learn as many tips as I can.
 
Re: torque limiting screw drivers ?

I use a torque wrench and torque screwdriver on terminations in the panel. Main, ground bar, neutral bar and circuit breaker lugs. All of these terminations have a torque range specified on their product label or packaging. I cannot find such a torque spec for P&S or Leviton receptacles or switches on their packaging or in their catalogs. What is the inspector wanting torqued?
 
Re: torque limiting screw drivers ?

In the handbook article 110 you will find the torque requirements for different screws and wire sizes.
Lou
 
Re: torque limiting screw drivers ?

Where is this at ???We have had a problem with utility subs using torque wrenches that have been tack welded at specified torque.They have been snaping the line lugs off the meter cans :mad: We have an inspector that will check bond screw for tightness on final and will fail if he can get 1/2 a turn out of it.But he hasn`t required a torque screwdriver.
 
Re: torque limiting screw drivers ?

In the handbook page 45 it states that this information is to be used for guidance only, if no information is given be the manufactures instructions. It was taken from UL 486B for aluminum and UL 486A for copper conductors. But I don't see how a inspector can fail you if he gets a 1/2 turn on a screw without a torque screwdriver when the torque spec for screw smaller then a #10 and a 3/64 width screw-slot for a a?#8 wire or smaller is only 7 in-pounds.
Lou
 
Re: torque limiting screw drivers ?

I would also make the point that over-torqueing is just as big a problem as under-torqueing. I read somewhere that most small lugs/screws are over-torqued and most large lugs are under-torqued. Under-torque can cause loose connections after repeated heat stress. I am sure we have all seen the results of over-torque, such as stripped threads and small guage wires almost severed at the point of connection (primarily under screws on breakers and neutral/ground bars.

I use a torque set on all large conductors and on small conductors within panels. My logic for within panels is that the torques are usually specified and that conductors in panels are in the same eclosure with other conductors of much high OCP or no secondary OCP (as in main panels).
 
Re: torque limiting screw drivers ?

i do not agree with the above post. overtorquing is a problem, but from what we run into, maybe 5 per cent of connection or termination problems are caused by over-torquing! the biggest problem with over-torquing is the damage to equipment contact aliegnment. consider a 100 amp fused disconnect feeding an elevator. if you over-torque the line side terminal without holding the terminal in place, you will bend the blade portion of the switch. once the blade is bent it looses surface contact area and reduces the current carrying capability of the switch. many times,when conducting an infrared scan, this problem will be common to an entire building because the same guy did most of the terminations!
 
Re: torque limiting screw drivers ?

Just a thought,if the installation instructions give you a torque range and you don't use it your in violation of the NEC for not following the listed installation instructions.
 
Re: torque limiting screw drivers ?

Originally posted by kendog:
Just a thought,if the installation instructions give you a torque range and you don't use it your in violation of the NEC for not following the listed installation instructions.
Click to expand...
This and the torqu values given in NEC to justify his rejection of electrical system.
 
Re: torque limiting screw drivers ?

I have been in this trade since 1973 and for the life of me I can`t remember ever seeing an inspector with a torque limiting screwdriver ;) Have had jobs tagged for rough in guy cutting in grnds/neutrals with a cordless and not setting the clutch and mashing the copper till it was paper thin.But have never had an inspector tag for torque screwdriver not being used ;)
 
Re: torque limiting screw drivers ?

An inspector should not have a torque wrench or a torque screwdriver. Once a connection has been torqued, doing it a second time could result in an over torqued connection. In other words, the torque values are not enforceable unless you are observed making up connections without using the proper tools or you don't even have the proper tools on the job. :D
 
Re: torque limiting screw drivers ?

Originally posted by amptech

I use a torque wrench and torque screwdriver on terminations in the panel. Main, ground bar, neutral bar and circuit breaker lugs. All of these terminations have a torque range specified on their product label or packaging. I cannot find such a torque spec for P&S or Leviton receptacles or switches on their packaging or in their catalogs. What is the inspector wanting torqued?
Click to expand...
I believe the torque specifications you are looking for (receptacles and switces) are listed on the yoke of the device in question, as part of all the seldom read stamping.
 
Re: torque limiting screw drivers ?

I agree with Charlie, no inspector should be sticking a screwdriver on someones work. Just for the reason he mentioned. Not only that, now that inspector is the last one to touch the work, and in my opinion he becomes the one responsible.
 
Re: torque limiting screw drivers ?

Just because you own a tool, doesn't mean you used it.

Some inspectors here require a letter on company letterhead stating that it has been done. But I have never had an inspector physically check.
 
Re: torque limiting screw drivers ?

I plan to start doing some residential on side, and would like to learn as many tips as I can.
Click to expand...
TIP # 1

People sleep in these buildings. If you start a fire, you can kill someone. Be sure you know what you are doing

Residential is not a place to "start" doing on "the side"
 
Re: torque limiting screw drivers ?

TIP #2 you are now working without liability insurance and workers comp.Do you have a masters license ? If not you might be breaking the law.
 
Re: torque limiting screw drivers ?

Dragonelectric, There is nothing visible on a P&S or Leviton device. I am looking at a P&S 5262 duplex and a Leviton BR-15 duplex right now.
 
Re: torque limiting screw drivers ?

Originally posted by charlie:
An inspector should not have a torque wrench or a torque screwdriver. Once a connection has been torqued, doing it a second time could result in an over torqued connection. In other words, the torque values are not enforceable unless you are observed making up connections without using the proper tools or you don't even have the proper tools on the job. :D
Click to expand...
The inspector did not have a torque screwdrive, but required the electrician to have one on hand before he would pas them. :eek:
 
Re: torque limiting screw drivers ?

Joe homeowner that mounted a receptacle and tv about 6 ft aff in the corner of his jetted tub in the corner :D
 
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