ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Ronald and Nancy Reagan in GE commercials
by Bill Addiss. 03/13/19 08:12 PM
Carflex in an RNC connector?
by gfretwell. 03/12/19 05:21 PM
Reverse-feeding transformer in PV system?
by HotLine1. 03/11/19 08:37 AM
Vintage stage lighting and equipment catalogs
by Albert. 03/09/19 06:21 PM
TJX Recalls Heating Pads
by Admin. 03/08/19 09:33 PM
New in the Gallery:
What is this for?
Plug terminals
Who's Online Now
0 registered members (), 25 guests, and 16 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
how tight do i tighten the lugs? #63346
03/13/06 11:39 PM
03/13/06 11:39 PM
Clydesdale  Offline OP
Joined: Nov 2004
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?

Work Gear for Electricians and the Trades
Re: how tight do i tighten the lugs? #63347
03/13/06 11:48 PM
03/13/06 11:48 PM
Active 1  Offline
Joined: Feb 2003
Posts: 687
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.

Re: how tight do i tighten the lugs? #63348
03/14/06 12:16 AM
03/14/06 12:16 AM
Clydesdale  Offline OP
Joined: Nov 2004
Posts: 138
yeah. foot pounds.thanks. I will check out some manufacturers' websites for some info..


Re: how tight do i tighten the lugs? #63349
03/14/06 03:21 AM
03/14/06 03:21 AM
e57  Offline
Joined: May 2003
Posts: 2,876
Usually listed in most equipment labeling, and sometimes on the lug itself.

Mark Heller
"Well - I oughta....." -Jackie Gleason
Re: how tight do i tighten the lugs? #63350
03/14/06 09:36 AM
03/14/06 09:36 AM
Last Leg  Offline
Joined: May 2005
Posts: 41
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.

Re: how tight do i tighten the lugs? #63351
03/14/06 10:48 AM
03/14/06 10:48 AM
renosteinke  Offline
Cat Servant
Joined: Jan 2005
Posts: 5,316
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.

Re: how tight do i tighten the lugs? #63352
03/14/06 01:00 PM
03/14/06 01:00 PM
Tom  Offline
Joined: Jan 2001
Posts: 1,044
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.
Re: how tight do i tighten the lugs? #63353
03/14/06 01:43 PM
03/14/06 01:43 PM
gfretwell  Offline

Joined: Jul 2004
Posts: 9,343
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
Re: how tight do i tighten the lugs? #63354
03/14/06 02:00 PM
03/14/06 02:00 PM
George  Offline
Joined: Feb 2002
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.

Re: how tight do i tighten the lugs? #63355
03/14/06 04:01 PM
03/14/06 04:01 PM
togol  Offline
Joined: Sep 2005
Posts: 421

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).]

Page 1 of 2 1 2


2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Member Spotlight
Campbell, CA
Posts: 356
Joined: August 2006
Show All Member Profiles 
Top Posters(30 Days)
Admin 9
Albert 3
Popular Topics(Views)
253,833 Are you busy
190,299 Re: Forum
179,994 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.032s Queries: 15 (0.006s) Memory: 1.0244 MB (Peak: 1.2013 MB) Zlib enabled. Server Time: 2019-03-18 17:55:19 UTC