Aluminum to Copper buss bar

[Adair]

Hello,

I am upgrading my electrical system from the AC breaker box to the 12 volt distribution panel. Where the wires dissappear into the hull, I am going to leave the original solid aluminum wiring. To avoid any corrosion issues, I imagine I will need a buss bar that is designed for this junction. Has anyone done this before? Is there a better way to extend the wires from where they come out of the wall? I need to extend them a couple of feet to reach my new distribution panel.

Cheers, Adair

[letsgo123]

Aluminium wiring had to be the biggest scam played on the general public, what happens is the different rates of expansion of copper and aluminium, alum. eventually gets loose under copper screws and starts arcing and heats up.
To make alum. and copper joints you require MARRETS that are copper&alum compatable, also if you go to an ELECTRICAL WHOLESALER you need a paste that is put on all aluminium wire terminal points. it prevents oxidization of the joint.
A suggestion if you have never made joints using disimilare metals have someone show you how, aluminium doesnt forgive mistakes.

good luck drive safe

[john hd]

Has anyone done this before?

yes, i do it every day at work. i'm a lineman at the power company.

the secret to successful aluminum to copper connections is the following:

clean
tight
adquate capacity for the current expected.
-and- you need to use a corrosion inhibitor!

by clean, you have to wire brush or sand the wire until it is bright.
by tight, a compression connector would be the best, crimp style. your idea of a seperate buss bar may well be the best practical solution. another idea may be the use of split bolts with a interface between the two conductors.
adquate capacity, means the connector should be rated for the job, a buss bar should be more than enough for your job. any splitbolt style that allows the wires to fit will work too.

the inhibitor needs to be applied liberally, less is not better.

the one thing i think you should shy away from is common wire nuts assembled dry. they will be trouble for sure!

john

[Adair]

Thank you both for your input and cautions. I have gone through the trailer and polished up every aluminum contact at the outlets and light fixtures and slathered them with an inhibitor designed for aluminum contacts. If I can reposition my fuse panel so that I can plug the existing wires directly into the contacts on the panel, that is my preference. If not I will look for a split bolt connector to bridge materials. I'll be sure to run it past the experts at the electrical supply.

It may keep me up at nights for a while, knowing that the aluminum is in there, working itself loose with every fluctuation in temperature, but I can't justify pulling the interior skin to re-wire.

Cheers, Adair

[Beginner]

My associates always made fun of me for carefully cleaning the light sockets and lights on my vehicles and then liberally applying high temperature wheel bearing grease (non-conductive) to both. I rarely have electrical problems, didn't have problems with my 1960 beetle after I had gone through it and cleaned/greased all the connections.
Then I found Hondas with Penzoil 707 (white grease) in all their connectors.
Beginner

[byamcaravanner]

Thanks John HD!

It's always good to have a "Pro" weigh-in on these topics.

I've done a lot of research on this topic as I am at the point in my restoration where I need to decide if I am going to re-wire or add the copper pig-tails.

Seems there are two products available to accomplish the pig-tail fix.

1. Aluminum Wiring Repair COPALUM Wire Connector Availability & Supply Source This is a proprietary system that is leased to an Electrical Contractor that has been specifically trained. Essentially, it is a "crimp" that uses a proprietary crimping tool.

2. AlumiConn | Aluminum Copper Connector | Aluminum House Wiring This is a system that uses little plastic housed Buss type connectors. These can be purchased and installed by a D-I-Y er but they are rather expensive.

If you can find an Electrical Contractor that is certified, the COPALUM system seems more compact... I suspect that this method is likely VERY EXPENSIVE.

The Alumiconn system seems nice but I am concerned about being able to fit all the "extra" connection material into the small junction boxes on my '67.

The third option is a "home-brew" system like John HD explained. I done right, I'm sure it would be just as successful as the others.

The jury is still out on what I will decide to do.

Good Luck!

[john hd]

wader

either of the solutions posted would work perfect.

i like the second one as it requires no special tools, obviously the crimp style would be similar to what utilities use.

one style we use involves a 100 ton press powered by a 5 horse briggs and stratton. but we are crimping wires as big as your wrist!

john

[byamcaravanner]

John,

Should I run into any BIG wires as I open up my tin can I'll know who to call. LOL!

Thanks for sharing your expertise.

[letsgo123]

DONT USE COMPRESSION CONNECTORS on wire sizes 10, 12 , 14, or smaller, you will regret using them at a later date, the above sizes of copper wire joined to alum. wire must be twisted with the anti oxide paste then use a MARR CONNECTOR (wire nut) , if done properly there will never be a problem. To futher reduce chances of oxidization at any wire joint, wrap the MARR COVERED JOINT WITH ELECTRICAL TAPE (3M #33) better still (3M #88) can get from home depot.

good luck

[byamcaravanner]

The Alumiconn connectors are good for 10ga thru 18ga in both solid and stranded wire. There are torquing specs based on the wire size and type.

[john hd]

if you guys do tape spend the extra money and use the scotch 88 tape.

i swear to god the power company would come to a screeching halt without it!

john