# Breaker Panel Torque Setting



## WyrTwister (Jul 22, 2013)

All appear to be in inch pounds . You probably are going to need a 1/4" drive torque wrench .

I will give you a hint , in about 35 years I have never used a torque wrench on a loadcenter . Tighten it tight , but do not break anything .

God bless
Wyr


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## md2lgyk (Jan 6, 2009)

Like WyrTwister, I have never torqued anything in a residential load center. I have a 200 amp Homeline panel in my house and it doesn't even have torque settings on the nameplate. The only times I've ever seen a torque wrench used on an electrical panel was when I worked maintenance at a nuclear power plant and on a nuclear sub when I was in the Navy.


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## brric (Mar 5, 2010)

Surely you meant to say 4/0 aluminum conductors.


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## Mr.HVAC (Jan 1, 2010)

Sorry, maybe I am confusing you guys, but I am asking for the torque settings because I do not know how to read the nameplate. It's my first attemp to upgrade the breaker panel and I want to make sure it's done properly due to my lack of experience.


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## Hick (Nov 21, 2014)

A torque wrench will likely be measued in inch pounds or foot pounds. The panel box is reading in inch pounds. If you have a torque wrench, likely a dial one. You dial it to the correct torque. In this example lets use the top one of 250. You would dial your wrench to 250 then torque it untill it "breaks" where the wrench gives way at that torque setting. That is how that works. If yours is measured in foot pounds. You just devide by 12. Thus a 250 LB-IN would convert to about 21 LB-FT. 250/12=20.8

However, as others mentioned. It is not necessary. Simply torque it down until it is tight but not so far where you are breaking it. A "snug" fit. Torque wrenches are very expensive & not necessary for something like common home wiring.


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## Jim Port (Sep 21, 2007)

The incoming hots and neutral are torqued to 250 inch pounds. The ground depends on the size.

Without using s torque wrench you are likely tightening too much.

I always torque the main connections. A torque wrench is less than $100. A professional should have the proper tools.


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## ritelec (Aug 30, 2009)

Jim Port said:


> A professional should have the proper tools.


yup.........

like having having the proper hammer with assorted chisels.


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## MTN REMODEL LLC (Sep 11, 2010)

Jim Port said:


> The incoming hots and neutral are torqued to 250 inch pounds. The ground depends on the size.
> 
> Without using s torque wrench you are likely tightening too much.
> 
> I always torque the main connections. A torque wrench is less than $100. A professional should have the proper tools.


 

JIM.... 


I respect your opinion and style of work unquestionably.... 

but just as a comment and observation..... I have never seen a electrician use a torqe wrench on any feeds. My observation is restricted to residential issues. I do know they should be torqued.... just commenting.

Best


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## Hick (Nov 21, 2014)

If the OP wants to go out & buy a torque wrench or already has one, more power to him. The LB-IN/LB-FT numbers, nor a torque wrench are difficult to figure out how to use. If you truly are unsure how to use it there are dozen of you-tube videos showing how its done. The only time I personally have used a torque wrench is doing gun smithing when I am fine-tuning rifles for accuracy. Other than that, have seen little use for it.

That said, using one for electrical IMHO is pointless BUT using one wont hurt anything. If you feel more comfortable buying/using one to do your electrical your welcome to. Following the specified directions on the panel box will in no way cause problems later down the road. It is entirely up to you. If you want to play on the safe side. Go ahead & use one.


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## Mr.HVAC (Jan 1, 2010)

Thanks guys,

I already have a torque wrench sitting in my tool box. Might as well use it. So just to clarify, the torque value for the #4 aluminum service entrance wires are 250 inch per pound? What about the #4 copper ground wire that goes to the ground rod and water line? Also what about the small neutral and ground wires that goes to the house? 
Thanks


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## nap (Dec 4, 2007)

hnguyen11033 said:


> Thanks guys,
> 
> I already have a torque wrench sitting in my tool box. Might as well use it. So just to clarify, the torque value for the #4 aluminum service entrance wires are 250 inch per pound? What about the #4 copper ground wire that goes to the ground rod and water line? Also what about the small neutral and ground wires that goes to the house?
> Thanks




the grounding electrode wire is 45 inch pounds

the small neutral and grounds are in the last two sections. You just look for the size of wire used and find the torque spec following it. Take note the last section is only for ground wires when putting more than one wire in a single hole. You cannot do that with neutrals.


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## Mr.HVAC (Jan 1, 2010)

Thank you very much all!

Got it now. I just feel safer to use a torque wrench since I have it and it is my first attempt to upgrade the breaker panel.


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## Oso954 (Jun 23, 2012)

Here is an interesting article on torquing electrical connections.
http://iaeimagazine.org/magazine/2010/07/16/the-difference-between-success-and-failure-how-a-torque-wrench-improves-system-reliability/

The bottom line is that without torque tools, only 25% of those tested got within 20% of the recommended torque.
The converse is 75% missed it by more than 20%.

While they used the 20% for these tests, do you think you would be satisfied with someone working to that standard on your house ?


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## WyrTwister (Jul 22, 2013)

Hick said:


> A torque wrench will likely be measued in inch pounds or foot pounds. The panel box is reading in inch pounds. If you have a torque wrench, likely a dial one. You dial it to the correct torque. In this example lets use the top one of 250. You would dial your wrench to 250 then torque it untill it "breaks" where the wrench gives way at that torque setting. That is how that works. If yours is measured in foot pounds. You just devide by 12. Thus a 250 LB-IN would convert to about 21 LB-FT. 250/12=20.8
> 
> However, as others mentioned. It is not necessary. Simply torque it down until it is tight but not so far where you are breaking it. A "snug" fit. Torque wrenches are very expensive & not necessary for something like common home wiring.


 My 1/2" & 3/8" torque wrenches were around $ 10 each at Harbor Freight .

I bought one for automotive & the other for HVAC .

Probably not the best quality ,but will work , no more than I will use them .

God bless
Wyr


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## md2lgyk (Jan 6, 2009)

Oso954 said:


> Here is an interesting article on torquing electrical connections.
> http://iaeimagazine.org/magazine/20...-a-torque-wrench-improves-system-reliability/
> 
> The bottom line is that without torque tools, only 25% of those tested got within 20% of the recommended torque.
> ...


The actual torque value is not that critical. Even the best torque wrench is not a precision instrument. The actual applied torque in any instance could easily be 20% either side of what the wrench is set for, which in almost all applications is perfectly acceptable.


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## busman (Nov 7, 2008)

md2lgyk said:


> The actual torque value is not that critical. Even the best torque wrench is not a precision instrument. The actual applied torque in any instance could easily be 20% either side of what the wrench is set for, which in almost all applications is perfectly acceptable.


What we've got here is a bunch of arm-chair metallurgists. I don't claim to know crap about metallurgy, but I do mostly residential and have never since I was licensed ever tightened a panel connection without a torque tool. I just know that if I tighten it with the proper tool and it fails, it's not my problem. My gift to myself when I passed the Journeyman exam was a Klein torque wrench set (over $1,000 many years ago).

The reality is that most people who are not using torque tools are over tightening small connections (frequently see the conductor almost severed on #12 and #14 connections) and under tightening (afraid to break the terminal) on large connections.

You can have all of the opinions you want, but the NEC requires using the correct torque (110.3 (B)).

Mark


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## stickboy1375 (Apr 28, 2012)

MTN REMODEL LLC said:


> JIM....
> 
> 
> I respect your opinion and style of work unquestionably....
> ...


Then you never saw an electrician...


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## stickboy1375 (Apr 28, 2012)

I have always used a torque wrench, I can guarantee every bolt not torqued is overtightened, putting stress on the threads and the conductors themselves...


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## WyrTwister (Jul 22, 2013)

We tried using a torque wrench on a 480 VAC fused switchboard we installed at a hospital .

Went back and " hand tightened " everything . They all felt " loose " compared to what we were accustomed to .

For right or wrong , we left the torque wrench at the shop , from then on .

I have since borrowed it a few times ( before I bought a 1/2" & a 3/8" torque wrench at HF ) for non-electrical applications .

But if someone wishes to use one , go right ahead .

God bless
Wyr


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## stickboy1375 (Apr 28, 2012)

WyrTwister said:


> We tried using a torque wrench on a 480 VAC fused switchboard we installed at a hospital .
> 
> Went back and " hand tightened " everything . They all felt " loose " compared to what we were accustomed to .
> 
> ...


S0 basically you went back and over tightened everything? How do you feel what 'loose' is? Thats WHY you use a torque wrench... 

I've gone back to jobs where they overtightened the lugs so much they stripped them out.

By the way, when the IR guys comes in a few years later for preventive maintenance, they are going to see the problem.


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## stickboy1375 (Apr 28, 2012)

http://ecmweb.com/contractor/do-you-have-calibrated-arm


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## 47_47 (Sep 11, 2007)

stickboy1375 said:


> http://ecmweb.com/contractor/do-you-have-calibrated-arm


From my days as an auto tech, I would have thought that more would be over-tightened, than under. Just because you put a torque wrench on a fastener, doesn't mean that its correct torque. You need to know how to use a torque wrench and make sure its calibrated. 

You electricians are lucky, all you have to deal with is a dry torque. Wait until the mfgr starts using stretch fasteners, angle torque...


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## WyrTwister (Jul 22, 2013)

stickboy1375 said:


> S0 basically you went back and over tightened everything? How do you feel what 'loose' is? Thats WHY you use a torque wrench...
> 
> I've gone back to jobs where they overtightened the lugs so much they stripped them out.
> 
> By the way, when the IR guys comes in a few years later for preventive maintenance, they are going to see the problem.


 Close to 35 years of experience directly , working for a contractor . Then there is at least 5 years in other fields that involve tightening fasteners .

So think what you wish , say what you wish .

Have a wonderful day .

God bless
Wyr


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