Grease on Lugs in Panel

I have seen several instances of grease being used inside panel boxes where large (service entrance) wires connect to lugs.

What type grease is this?
Is it required?
Is it recommended?
etc.?

Thanks,

 

This is an anti-oxidant. Aluminum will corrode, when it does the resistance goes up an would cause the connection to heat up as current flows. This is designed to prevent this from occuring.

I always use it on AL conductors.

 

I use it on all screws on lugs no matter what the type of wire. It saves seized threads and allows for retightening in the future. Also a dry thread may never tighten down well. It just stops turning to thread friction and requires so much torque just to turn itself that not much real compression is being applied to the wire.

 

Sounds reasonable to me! Do you use the aluminum antioxidant grease? Is pipe thread dope just as good? Do you have a brand/type recommendation? I am working with copper wire.

 

Yes,,, alum anti ox,,, No-Loks or Oxy-Ban or something,, sometimes I spray screws with wd 40,, that keeps them from seizing during installation and isnt so messy. I spray neutral bar too sometimes,,, just a little it prevent dry thread seizing. Even screws in some big breakers. Actually we oil almost all bolts everywhere during assembly, not just electrical, work to make removal easy and to make proper tightening possible.

 

You may use any type of antioxidant that is APPROVED for use in electrical wiring. For the screw terminals, use a silicone-based lubricant. Do not use WD-40 or any other petroleum-based lubricant on or near energized electrical equipment, as it is combustible and not rated for this purpose, not to mention dangerous. Picture this....You have an enclosed panel with combustible vapors inside, and a breaker trips, causing an arc....not a good scenario.

 

I am talking about putting a drop on a screw,,, I agree with the flamability issue and definately dont spray it all over the inside of the can. I wipe off any overspray also.

 

Just out of curiosity,, out of the thousands of cans of sprays that get used on switches, relays and contacts every year in factories and industrial applications, especially in humid and corrosive locations has there been reported fires from using it?

 

The "Grease" that you refer to is just as you have been told it is an anti-oxidant compound. One trade name is No-Alox, this is used to prevent oxidation of the aluminum conductors. One thing that nobody has mentioned is the fact that it is recommended that the conductors be burnished before the application of an anti-oxidant compound. To burnish means to use a wire brush and polish the aluminum. This is an important part of the process as you need to clean the dirt and oxidation that is already in place off of the conductor before the application of the compound. Failure to due this will cause the connection to fail!! I have seen this happen first hand.
You must also use a torque wrench and be sure to torque all of your terminations to maufacturers specified values. This is most important on aluminum and should be done on all terminations, including those with copper conductors.

 

Yes I have seen and heard of fires in industrial settings when a person used WD40 etc. without knowing they had to use non conductive and non combustable electronic type sprays.

If you did a test sometimes nothing happens with oil based spray and sometimes the points just set there and fry. A lot depends on the condition of those electrical contacts when the wrong type spary is used.

Wg

 

Yes,, I dont like to spray on contacts and tend to use it frugally in linkages and surely wouldnt want to spray something flamable on arcing contacts. It could catch fire right in the face. In the original statement I really meant to only apply to threads of fasteners.

 

sberry, I agree with your thoughts of lubricating threads and linkage. But wanted to point out that there is sprays on the market designed as electrical and electronic contact cleaners that are both non conductive and electrically safe per UL testing. I just wanted to make sure people knew the difference between the types of sprays we were talking of.

Wg