Thread Tools Search this Thread Display Modes
Old 04-06-2014, 01:46 PM   #1
2 Rivet Member
69SlvrBelle's Avatar
1969 27' Overlander
Wrightsville Beach , North Carolina
Join Date: Oct 2013
Posts: 36
Cu-Al Circuit breakers

Hi to everyone. I am in the midst of replacing my circuit breaker panel as it is original and rusty and corroded. As I was taking some pictures of it so I would rewire it correctly, I noticed that the breakers have Cu-Al written on them.
Can I replace them with "regular" circuit breakers or do I need to stick with the Cu-Al type? They are GE and are thin in their width, THQP type I beleive. I went to a box store yesterday and the electrician there said to stick with the Cu-Al type.
In doing a little research it appears that the Cu-Al is a "rating", and meant to be used with aluminum wiring. Are the 1969 Airstreams wired with aluminum wiring or copper clad, aluminum wiring? I am a little confused and want to keep the trailer safe.
Everyones help is greatly appreciated.


69SlvrBelle is offline   Reply With Quote
Old 04-06-2014, 02:21 PM   #2
Rivet Master
switz's Avatar

2014 31' Classic
2015 23' International
2013 25' FB International
Apache Junction , Arizona
Join Date: Sep 2012
Posts: 5,063
Images: 8
Cu-Al refers to copper-aluminum so the breakers are rated for either type of wire. However, because of galvanic action, never put copper and aluminum wire together under the same screws as one will dissolve the other.

One usually has to increase aluminum wire size by one size to carry the same current as copper. For a 20 amp circuit, one would use #12 copper wire or would use #10 aluminum wire.

WBCCI Life Member 5123, AIR 70341, 4CU, WD9EMC

TV - 2012 Dodge 2500 4x4 Cummins HO, automatic, Centramatics, Kelderman level ride airbag suspension, bed shell

2014 31' Classic model 30 twin beds, 50 amp service, 900 watt solar system, Centramatics, Dill TPMS, disc brakes, 16" tires & wheels
switz is offline   Reply With Quote
Old 04-07-2014, 09:36 PM   #3
Wise Elder
Jammer's Avatar
2010 30' Classic
Vintage Kin Owner
South of the river , Minnesota
Join Date: Dec 2009
Posts: 4,129
Originally Posted by 69SlvrBelle View Post
Hi to everyone. I am in the midst of replacing my circuit breaker panel as it is original and rusty and corroded. As I was taking some pictures of it so I would rewire it correctly, I noticed that the breakers have Cu-Al written on them.
Can I replace them with "regular" circuit breakers or do I need to stick with the Cu-Al type?
It depends on whether you have aluminum wire. I believe that some trailers, but not all, made in 1969 used aluminum wire.

The advice on dealing with aluminum wire is controversial with the most conservative approach being to pull it all out and replace it with copper.

Other approaches are complicated to assess for safety. Part of the problem is that several alloys were in use, with some being more prone to causing fires from high-resistance terminations than others. Part of the problem is that CO-ALR rated devices haven't been manufactured for years and there is concern that old stock ones may have had the antioxidant coating deteriorate due to age.

One recommendation is to use one of two approved copper-to-aluminum connector blocks to retrofit a copper pigtail. They are expensive and difficult to get with one system only being available to licensed electricians who have gone through special training from the manufacturer of the connectors.
To learn to see below the surface, you must adjust your altitude
Jammer is offline   Reply With Quote
Old 04-10-2014, 05:07 PM   #4
Rivet Master
drboyd's Avatar

1978 25' Tradewind
Metro Phoenix , Arizona
Join Date: Jun 2003
Posts: 1,430
I have been given to understand that the problem with aluminum is that it doesn't spring back after being stressed like copper does.

So, an aluminum wire under a screw gets hot and expands, and it squishes out as it does so. But it doesn't come back to the original shape, so now it's a little bit loose under the screw. So, the same thing happens next time, only more so.

I believe (note all the weasel words here) that a Cu/Al rated device will maintain a constant pressure on the conductor even it it changes size a little bit.

The best answer, however, is to use only copper wire.
"Between what matters and what seems to matter, how should the world we know judge wisely?" - E.C. Bentley, Trent's Last Case
drboyd is offline   Reply With Quote
Old 04-10-2014, 08:50 PM   #5
Kevin245's Avatar

Vintage Kin Owner
... , ...
Join Date: Jul 2007
Posts: 9,637
Images: 9
The Cu-Al designation means the breaker can be used with either copper or aluminum wire.

The issue with aluminum wiring is the potential for heat build up in connections due to increased resistance caused by oxidation. This causes the aluminum wire to expand then contract, thereby loosening the connection which can lead to meltdown, or worse. The key to successful service with aluminum wire falls into three categories.

1) Use connectors, switches, receptacles, breakers, etc. rated for aluminum service.

2) When joining copper to aluminum wire use a Cu-Al split bolt or equivalent.

3) Always use an oxide inhibitor on all aluminum connections. Oxygen is your enemy.

BTW many homes with copper wiring still have aluminum feeds to the kitchen range and HVAC systems.

I do not know when Airstream used aluminum wire, but if my rig had it I would not rip out interior skins to replace it. If I was doing a full blown restoration and had access to accommodate a change then yes I would make swap. Otherwise I'd inspect and replace compromised connectors, No-Ox them and keep on enjoying my rig.



"You wouldn't worry so much about what others think of you if you realized how seldom they do."

Eleanor Roosevelt

Kevin245 is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Circuit breakers in '09 International 25FB donna01 Electrical - Systems, Generators, Batteries & Solar 6 03-13-2011 02:15 PM
Circuit Breakers Alumanutz Lights - Interior & Exterior 1 09-11-2008 08:02 PM
Circuit Breakers Tripping bgarver Electrical - Systems, Generators, Batteries & Solar 2 11-16-2007 10:52 PM
Circuit breakers,94 33ft Motor Yacht rayschell Batteries, Univolts, Converters & Inverters 4 07-10-2005 11:35 AM
Electric Heaters Tripping Circuit Breakers streamlean General Motorhome Topics 11 01-20-2004 09:29 PM

Featured Campgrounds

Reviews provided by

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 04:18 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.