Thread: Solid aluminum conductors OK?

This panel is in a house about 20 years old, I am guessing it is original. It is 200 amp. Two of the circuits appear to have solid aluminum conductors, as far as I can determine through the paste on the wires. The ones in the photo are on a 30 amp breaker. The wires appear larger than 10 gauge. The labels on the breakers state AL-CU. I understand stranded conductors can be OK, but I am not sure about solid ones. Is there a problem here?

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First of all, aluminum wiring size is one size larger than copper for the same breaker. Second, there are numerous issues with aluminum wiring in panels and in houses (outlets, fixtures, and switches). Its not automatically bad, but there are problems related to aluminum wiring.
You should do some research and become familiar with what the issues are, how to recognize them, and how to report them.

[QUOTE=Jack Feldmann;255307]First of all, aluminum wiring size is one size larger than copper for the same breaker. Second, there are numerous issues with aluminum wiring in panels and in houses (outlets, fixtures, and switches). Its not automatically bad, but there are problems related to aluminum wiring.

Aluminum wire on branch circuits is known to cause problems, due to heating and cooling of the wire, under normal use conditions. The wire will expand and shrink at each connection point. This includes breakers, outlets, switches. The expanding and shrinking will loosen every connection, including the connection at the breaker. Loose connections generate heat, which exacerbates the problem. If you prefer a high premium for fire insurance, then aluminum wire is the way to go.

I don't see a big problem here but report that you want the connections checked. A dryer circuit has only two terminations. The gauge should be #8 for 30 amps.

Jimmy, I'm not sure why you quoted me, but to clarify, iI'm well aware of the issues with aluminum wiring. However, if properly sized, installed, and maintained, it is fine. Maintained is the key word here, as well as properly installed.
Personally, I would not own a house with it, but I'm sure as heck not going to tell someone not to buy a house with it, or tell them it all needs to be replaced.

Originally Posted by Jimmy Roberts

Aluminum wire on branch circuits is known to cause problems, due to heating and cooling of the wire, under normal use conditions. The wire will expand and shrink at each connection point. This includes breakers, outlets, switches. The expanding and shrinking will loosen every connection, including the connection at the breaker. Loose connections generate heat, which exacerbates the problem. If you prefer a high premium for fire insurance, then aluminum wire is the way to go.

Before making statements about general opinions on Aluminium wiring, it's best to get recent information. The OP stated that the panel ( and therefore presumably the wiring) appeared to be 20 years old and original, which puts the installation date at around 1995.

Check the Aluminum category on the cable before making these sorts of statements. AA-1350 Aluminum wiring as used extensively prior to 1987 had a higher "creep" rate than the more modern AA-8800 wiring.

Modern wiring solutions still use Aluminum wiring, and not all Alumina wiring is "problemmatic"

The major cause for concern is still where the wiring meets the fitting, whether that be at the breaker or receptacle/switch end. As long as these are the correct type, and have been installed correctly, and the same consideration is given to the wiring installation as would be given to copper, then there is no greater concern with Aluminum residential wiring than there is with Copper.

While I recognised this is from an Aluminum manufacturer, and may appear to give a somewhat partisan view, this link has all the relevant details in a single place. You can spend the time validating what they say, I did, and couldn't find any provable contradictions.

Aluminum Building Wire 40 Years Later

As to the Local Jurisdictional codes that provide restrcitions, or the particular policies that some money grabbing insurance companies will implement to spread fear and derision in order to make a quick buck are concerned I can't comment, but as with all things, I find it pays to educate yourself to the best of your ability before giving a client a generalist statement based upon hear-say and outdated rhetoric.

I hope this helps.

Someone correct me if I'm wrong but the problems associated with aluminum wiring was mostly with 120 V branch circuit wiring size 12 & 14. I would note the absence of anti-oxidant paste where aluminum is exposed. Here is a good source:
Aluminum Wiring Hazards: The Aluminum Wiring Repair Website - How to Identify and Repair Aluminum Wiring in buildings

Looking closer there may be anti-oxidant paste applied to those wires.

Originally Posted by Tom Rees

Someone correct me if I'm wrong but the problems associated with aluminum wiring was mostly with 120 V branch circuit wiring size 12 & 14. I would note the absence of anti-oxidant paste where aluminum is exposed. Here is a good source:
Aluminum Wiring Hazards: The Aluminum Wiring Repair Website - How to Identify and Repair Aluminum Wiring in buildings

Looking closer there may be anti-oxidant paste applied to those wires.

14 was not allowed. 12, and 10 ga., (15 and 20 amp 120v).

Originally Posted by Tom Rees

Someone correct me if I'm wrong but the problems associated with aluminum wiring was mostly with 120 V branch circuit wiring size 12 & 14.

Rick addressed the size part, I'll address this part "mostly with" ... how many 30 amp and greater circuits are there compared to 15 and 20 amp circuits?

Rick and Jerry, I agree on both points, THANK YOU!!

I don't see any problem with the installation. Antioxidant paste was used on the termination to the breaker. The cable used was either a SEU or SER aluminum cable and the conductors are solid for this size cable. Most important check is to be sure the connection is "tight".

Originally Posted by Steve Nagy

Most important check is to be sure the connection is "tight".

I urge caution in retightening aluminum terminals.

The terminals should be (should have been) torqued to the proper specifications when installed, with aluminum you can retorque and retorque and retorque until the terminal screw cuts the conductor in too (and the screw has already excessively deformed and destroyed the conductor long before the conductor is cut in two ... you just don't realize you are doing it until then.

Originally Posted by Jerry Peck

I urge caution in retightening aluminum terminals.

Agreed. So the screw is tight, is it all good to go then? Or you've tightened it a bit, what about the other end and maybe junctions?

Home inspectors here are not permitted to perform work in a panel and rightfully so. Why would you take on more liability as the last person to touch it?

Originally Posted by John Kogel

So the screw is tight, is it all good to go then?

If it looks loose, or you bump or push the conductor and suspect it is loose, write it up as needing to be properly repaired (cut back, stripped off, inserted into the terminal, and the terminal retorqued - or the electrical contractor may decided that the end of the conductor is not damaged and is suitable to be reused ... that is THEIR decision, NOT the home inspectors decision - the home inspector DOES NOT WANT to be tied to any current or future problem from that connection).

There is also no need to call for "further evaluation", just stand up, hitch up your big-boy pants, and call for a proper repair ... then leave it up to the electrical contractor to properly repair it.

I realize this is slightly off track from the OP and question about a 30-amp circuit - I've seen that once before where all the 120-amp branch circuit wiring was copper but the dryer or stove was aluminum.
Inspected a house recently with all aluminum wiring. Breakers in the panel were rated for AL/CU.
I looked at one outlet in the kitchen, and noticed that the terminal screw was stamped AL/CU. Ok.

But the light switch next to it was rated for CU only. Got me to thinking that one of the situations you can run into with AL wiring is that while the original outlets may remain the same, the light switches and light fixtures are often replaced for one reason or another by home owner. Which increases the risk of overheating at the device connection. So even if everything was 'properly installed' originally, it is critical to recommend a complete survey by an electrician of all the wiring in the house.