# AL to CU



## charlie Bob (Jul 26, 2009)

I've Always used Aluminum/Copper split bolt connectors.
But the other day i put my self in a bind by not checking my supplies in my truck before a job.
We were upgrading a service.Thought over head wire from Trans. were copper, not they were aluminum. We were 30 miles to closest supply store.
I used regular copper (or whatever they are made of)split bolts.
I put a whole lot of an antioxidant grease that i carry in my truck, for copper to aluminum connections.

-Has anyone done that before?
-Do you trust that antioxidant?
-Do you evenl use it if using aproved AL/CU split bolts?

Thanks.


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## MDShunk (Jan 7, 2007)

A trick I learned from an old electrician for using copper or bronze split bolts to splice AL to CU.... cut a short length of sheet metal from a Madison strap and form it into a tube to put over the stripped end of the AL conductor. Terminate the AL and the CU in the split bolt. The AL does not react with the steel and the steel does not react with the copper and/or bronze. 

I'm not proposing this method necessarily, but I'm just stating what has been demonstrated to work. I have already taken out old services that were fed with AL SE cable that was terminated in pure copper lugs in the old panel. The old installers often used that steel sheet metal tube trick to terminate AL cable in copper lugs.


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## william1978 (Sep 21, 2008)

I've seen romex conn. used as split bolts and they had been up there for years. So I don't think your install is all that bad.


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## waco (Dec 10, 2007)

All the service drops I've encountered have been aluminum, but I use common romex connectors to make the splice since it is temporary anyway and split bolts are too expensive to just give to the PUCO people. I don't use anti-oxidant on those temporaries, but I do on the meter socket and panel. I just tape them.

On large services using copper, I still use anti-ox. They have all been laterals to apartments and the connections have been permanent, not temporary.


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## busymnky (Feb 16, 2009)

I usually use those insulated lugs, some of which are rated for al/cu. Can't help on the split bolts but yes I use deox even with a rated connector. As long as you got them tight and taped them you should be okay imo.


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## charlie Bob (Jul 26, 2009)

MDShunk said:


> A trick I learned from an old electrician for using copper or bronze split bolts to splice AL to CU.... cut a short length of sheet metal from a Madison strap and form it into a tube to put over the stripped end of the AL conductor. Terminate the AL and the CU in the split bolt. The AL does not react with the steel and the steel does not react with the copper and/or bronze.
> 
> That sounds like a handy trick to have up your sleeve, Mark.


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## s.kelly (Mar 20, 2009)

Aside from puple color and UL listing I think no ox is the only difference between cu/al wirenuts and any others
I think your solution is probably good,just mabye not listed


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## partimer31 (Jun 9, 2009)

Charles Bob try not to beat yourself over what you have done.

Now we all know a neat trick, that MDSkunk has shared with us. :thumbsup:


But if I were your boss I would want to know, you did this. Not to fire
you, but in my Company I along, take full responsibility for what my workers
do. If a worker got the job done, but used a product he shouldn't.
I would no fire him, I would thank him for being honest, and coming forward
with this information. 

But then again I am not your boss.

Your boss might be a real jerk, and would fire you once you told him.

Only your can read your boss. and the decision to tell or not tell is in
your hands.


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## 220/221 (Sep 25, 2007)

I personally would not leave it. 

I don't think the anti oxident is the issue in this case.

I have heard of Al wires terminating in copper lugs and causing issues.



But.....I have also seen a 15 year old installation where two screw romex connectors were used for the same purpose.


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## bobelectric (Feb 24, 2007)

Has anyone personaly seen damage from direct contact of al to cu?


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## MDShunk (Jan 7, 2007)

bobelectric said:


> Has anyone personaly seen damage from direct contact of al to cu?


Yes.


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## shockwave1221 (Jul 1, 2011)

Hi everyone, I hooked up a few split bolts in my 35 kw generator. The output wire is 4/0 and the wires off the genset consist of multiple seperate #4 wires. The generator is setup for 3 phase. The connectors are made by islco. My question is I torqued the crud out of them and taped them all up with electrical tape rubber tape and the other stuff made by 3m all of this in reverse order. I then saw the guggested torque rating on the ilsco website. I used a 18 inch ratchet with a 1.5 inch socket and a 1 inch open wrench. Am I going to be ok or will I have to tear it all apart. I used the anti corrosion paste made by ideal and the split bolts are al/cu rated.


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## adamv7010 (Mar 21, 2011)

shockwave1221 said:


> Hi everyone, I hooked up a few split bolts in my 35 kw generator. The output wire is 4/0 and the wires off the genset consist of multiple seperate #4 wires. The generator is setup for 3 phase. The connectors are made by islco. My question is I torqued the crud out of them and taped them all up with electrical tape rubber tape and the other stuff made by 3m all of this in reverse order. I then saw the guggested torque rating on the ilsco website. I used a 18 inch ratchet with a 1.5 inch socket and a 1 inch open wrench. Am I going to be ok or will I have to tear it all apart. I used the anti corrosion paste made by ideal and the split bolts are al/cu rated.


If you didn't strip the split bolts out and they're listed for al/cu then id say you'll be ok


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## AFOREMA1 (Nov 23, 2009)

E


shockwave1221 said:


> Hi everyone, I hooked up a few split bolts in my 35 kw generator. The output wire is 4/0 and the wires off the genset consist of multiple seperate #4 wires. The generator is setup for 3 phase. The connectors are made by islco. My question is I torqued the crud out of them and taped them all up with electrical tape rubber tape and the other stuff made by 3m all of this in reverse order. I then saw the guggested torque rating on the ilsco website. I used a 18 inch ratchet with a 1.5 inch socket and a 1 inch open wrench. Am I going to be ok or will I have to tear it all apart. I used the anti corrosion paste made by ideal and the split bolts are al/cu rated.


Hi shockwave you already posted this in its own thread so how about not spamming someone else's thread and asking the same thing repeatedly :thumbup:


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