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torque #91303 01/09/05 11:00 AM
Joined: Dec 2004
Posts: 52
K
kd Offline OP
Member
When I torque lugs using Aluminum wire, I will apply, say 50 ft. lbs., then several days later check the torque. It will be down to, say, 35 lbs, so I re-torque it. Other ECs say you should just torque it and forget it--that the loss in tightness is built-in to the required torque. Of course Copper holds its torque so it is not a problem. What do you guys and gals say about this?

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Re: torque #91304 01/09/05 11:47 AM
Joined: Jan 2001
Posts: 1,044
Tom Offline
Member
Torque it once to the specifications for the lug & leave it alone.


Few things are harder to put up with than the annoyance of a good example.
Re: torque #91305 01/09/05 12:37 PM
Joined: Jan 2004
Posts: 1,507
G
George Little Offline
Member
How does an inspector know how much you've torqued a connection? I am a fan of the break away connection.


George Little
Re: torque #91306 01/10/05 01:38 AM
Joined: Dec 2004
Posts: 86
P
Physis Offline
Member
Another reason to not like aluminum as a conductor.


Sam, San Francisco Bay Area
Re: torque #91307 01/10/05 08:13 PM
Joined: Apr 2001
Posts: 518
J
John Steinke Offline
Member
Not "another" reason- THE reason! Aluminum is notorious for "creep" when over-torqued. Aluminum should not be torqued to the same values as copper for this reason.
Simply put, too much pressure causes the metal to flow, leaving you with a loose connection. Make sure the value you're using is the correct on, and not "something always used."

Re: torque #91308 01/12/05 01:31 AM
Joined: Dec 2004
Posts: 52
K
kd Offline OP
Member
Aluminum association torque table shows the sasme values for Cooper and Aluminum.

Re: torque #91309 01/17/05 09:24 PM
Joined: Aug 2001
Posts: 599
N
Nick Offline
Member

Re: torque #91310 01/18/05 12:21 PM
Joined: Nov 2000
Posts: 2,148
R
resqcapt19 Offline
Member
The following is a very important quote from the document that Nick has posted a link to.
Quote
It is often asked whether bolted connections require periodic retightening. The simple answer is NO. Once the connector is installed with the proper torque, repeated tightening could actually damage the connector and/or the conductor and eventually lead to a failure.
Don


Don(resqcapt19)

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