Aluminum to brass

[hilotech]

We are currently building a new substation and brass 4 hole pads were purchased for connecting our conductors to our equipment. We will be using 556 aluminum conductors and connecting to an aluminum pad on the equipment. Can anyone tell me if this is acceptable and, if possible, point me towards any literature that supports your posistion.

Thanks

 

[rasevskii]

No you cannot. Aluminum to brass or copper requires special fittings or at least a Copal plate between.

Other experts here invited to comment.

We nearly burned up a generator terminal box at 11kV where the contractor had bolted directly aluminum lugs to the copper busbars of the generator. The solution had to be to go out and get special copal lugs fitted to the cable terminations. After only around 10 hours operation at around 1500A.

Are you really in Hilo where it never stops raining??

regards, rasevskii

 

[hilotech]

Yes I am, and yes it is with no end in site.

We never make those types of connections here, however we have a new designer who instists we can.

 

[rasevskii]

I was in Hilo in 99. Are the two old hydro plants there still running? I heard a new unit was put in a few years back to replace one of the old that was damaged. Real moneymakers.

regards, rasevskii

 

[hilotech]

we have a couple of units from 1906 that are still running.
You are correct, about 5 years back we had a unit come apart and we replaced it with a new one.

We are about 30% renewable here between solar, wind, hydro and geothermal.

 

[alehman]

I agree with the above. You should not do that without an engineered connector, especially considering the environment.

I was also in Hilo a few years ago visiting family and friends. My supervisor was born and raised there. Also Ed Case (candidate for US House) is a cousin.

I'm interested in wind generation. Any idea how much there is on the Big Island?

Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.

 

[hilotech]

We have about 30MW in two different farms. I really hate wind power we are small and it plays hell with our system. Geothermal is the only way to go.

 

[stevenal]

The conductor is AL and the pad on the equipment is AL? No reason to transition, use an AL pad compressed on to the conductor.

 

[alehman]

Al to Al should be fine. Al to brass, no.

30MW is probably a fairly significant fraction of your total capacity? I could see that being a problem.



Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.

 

[jghrist]

Can anyone tell me if this is acceptable and, if possible, point me towards any literature that supports your posistion.

Most likely, the connector will be UL listed for copper conductor only. This should support the position that it is unacceptable to use it on aluminum conductor.

 

[hilotech]

That is what I did. I asked who his supplier was and then got literature from them stating it was for copper only.

thanks all for the help!