# Help with torque values for busbar



## Paynee (Jul 10, 2011)

Hi all,

I'm after some help regarding the required torque values for busbar connections, I am joining two pieces of copper busbar, through bolted using 5/16" bolts. Had a search around online and cant seem to find any relevant information.

Thanks in advance.
Dave


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## EJPHI (May 7, 2008)

Because you are through bolting and not threading the fastner into the bus bar, you can just use the recommended torque for the bolt/nut combination. This information is easy to find. If this is an assembly you are buying from a manufacturer, they should supply the torque values.

EJPHI


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## Paynee (Jul 10, 2011)

It is a component that has been removed and refitted to another location i thought there may have been a torque value specific to it being an electrical so as not to possibly distort the copper busbar and compromise the connection.

Thanks


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## EJPHI (May 7, 2008)

The bolt is compressing the sections of bus bar together. It would be very difficult to come up with enough torque to distort them. If you have some spare pieces, you could put enough torque on the bolt to shear off the head and then measure the resulting distortion in the bus bars. Betcha there is none.

EJPHI


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## MDShunk (Jan 7, 2007)

Darned tight, plus one-quarter turn. 

The Professional Electrical Apparatus Recycler's League ( PEARL ) has generic torque specifications in Table 1 of their "reconditioning standard". This is helpful when dealing with vintage and obsolete equipment, when it's being relocated, refed with new conductors, etc., when the original torque specifications are unknown and not available by other means. 

http://www.pearl1.org/pdfs/pearl.pdf


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## Zog (Apr 15, 2009)

Here is the ANSI spec


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## tkb (Jan 21, 2009)

There is also Annex I in the NEC.


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