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#63346 - 03/13/06 07:39 PM how tight do i tighten the lugs?
Clydesdale Offline
Registered: 11/25/04
Posts: 138
How tight do I tighten the lugs down on a 4/0 Aluminum service conductors? Or for that matter...any lugs? I have heard it has to be 20lbs PSI...but not sure...anyone?
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#63347 - 03/13/06 07:48 PM Re: how tight do i tighten the lugs?
Active 1 Offline
Registered: 02/22/03
Posts: 687
Loc: Grayslake IL, USA
Maybe you mean foot pounds, inch pounds, or nuton meters.

Torque wrench.

I don't know any defult torque numbers if you can't find manufactures specs.
#63348 - 03/13/06 08:16 PM Re: how tight do i tighten the lugs?
Clydesdale Offline
Registered: 11/25/04
Posts: 138
yeah. foot pounds.thanks. I will check out some manufacturers' websites for some info..

#63349 - 03/13/06 11:21 PM Re: how tight do i tighten the lugs?
e57 Offline
Registered: 05/27/03
Posts: 2876
Loc: S.F.,CA USA
Usually listed in most equipment labeling, and sometimes on the lug itself.
Mark Heller
"Well - I oughta....." -Jackie Gleason
#63350 - 03/14/06 05:36 AM Re: how tight do i tighten the lugs?
Last Leg Offline
Registered: 05/04/05
Posts: 41
Loc: Houston, Texas
It is all dependent on the size and what it is made of (steel, zinc, etc). I found a chart years back that had standard tightening torques, per types and sizes, you might find something like that. Of course, manufacturers recommendations are always best.
#63351 - 03/14/06 06:48 AM Re: how tight do i tighten the lugs?
renosteinke Offline
Cat Servant
Registered: 01/22/05
Posts: 5316
Loc: Blue Collar Country
A little's "pound inches'...not 'inch pounds.

Otherwise, unless the connector is marked differently, here are the values UL uses:
Slotted scrw head..50 pound inches

Hex or socket head...250 pound inches

Split bolt...500 pound inches.

This information is also published in |Ferm's Fast Finder"....which is probably the ultimate NEC index. Available from the IAEI and NFPA.
#63352 - 03/14/06 09:00 AM Re: how tight do i tighten the lugs?
Tom Offline
Registered: 01/01/01
Posts: 1044
Loc: Shinnston, WV USA
Everyone left out the most important torque range called "erks." This is the sound the fastener makes just before breaking or stripping out. :-)

Most meter sockets have a label that states the torque value. Sometimes for the breaker it is marked on a label in very small type or is embossed into the body of the breaker, both of which are hard for us older guys to read.
Few things are harder to put up with than the annoyance of a good example.
#63353 - 03/14/06 09:43 AM Re: how tight do i tighten the lugs?
gfretwell Offline

Registered: 07/20/04
Posts: 9038
Loc: Estero,Fl,usa
The "erk" brings up an interesting point. Generally torque specs are based on a lightly oiled fastener. The "erk" is actually the galling of a dry fastener in the threads. Is there a listed lubricant for these fittings?
Friction in the threads could wildly alter the actual clamping force at any given torque, particularly in a termination that has been oxidizing for a while. (In use or on the shelf)
Greg Fretwell
#63354 - 03/14/06 10:00 AM Re: how tight do i tighten the lugs?
George Offline
Registered: 02/23/02
Posts: 375
Clydesdale ---

I think pressure (psi) is the best measure but since we have screw fasteners we are limited to measuring torque. Torque is a poor measure. Being affected by lubrication, finish, and dirt.
#63355 - 03/14/06 12:01 PM Re: how tight do i tighten the lugs?
togol Offline
Registered: 09/15/05
Posts: 421
Loc: NW In. USA

I have used Naptha, MineralSpirits, charcoal starter...any clear solvent,
Diesel, Kerosene, just a little dab on the threads like a charm


great for drilling and tapping too

[This message has been edited by togol (edited 03-14-2006).]
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