Copper/Aluminum mix

[JohnC]

Hi,

I have not seen this before in a panel. A Copper/Aluminum mix on a couple of breakers? Is this allowed? In addition the main disconnect is in the garage, so I told my client that the panel in the house is the sub panel and grounds and neutrals should be separated. The realtor told me I was wrong that "technically" the main disconnect is at the panel in the house. I really don't give a s--t about his thoughts and think he wrong, but I thought as I'm writing this report I would ask for input from the people whose opinion I do care about.

John Callan

Download Attachment: Aluminium & Copper.jpg

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Download Attachment: Grounds and Neutals.jpg

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[Brandon Whitmore]

Hi John,

If the service equipment is in the garage, then the interior panel is not the main disconnect, so the neutrals and EGC's should not be tied together. Was there a 4 wire feed run to the interior panel?

Whether or not the double tapping and aluminum/ copper wires sharing the same breaker connection is allowed is dependend upon the manufacturers listing. That goes for the double lugged neutrals as well.

The breakers look like they are Murray breakers. I don't think any of them are listed for double taps.

EDIT: There are too many neutrals and grounds secured under single terminal screws-- that's wrong for sure.

Also, the white insulated ungrounded conductor (hot) needs to be marked as such.

[JohnC]

Thanks Brandon,

No 4 wire feed to breaker’s, I also agree about the two many neutrals and grounds secured under single terminal screws. The breakers were listed Crouse Hinds which I think are the same as Murray. I'm aware about the double taps. I'm still not sure about the aluminum/ copper wires sharing the same breakers. Most likely will recommend a licensed electrician look at it unless I find out for sure.

John Callan

[Jim Katen]

Hi,

I have not seen this before in a panel. A Copper/Aluminum mix on a couple of breakers? Is this allowed?

No. The breakers are only listed to accept a single conductor. You can't have two copper wires there, let alone a copper and an aluminum wire. If they choose to solve this by joining the two wires together before the breaker, they'll have to find a connector that's rated for copper & aluminum in combination. An alumiconn connector or a simply split bolt would work fine.

In addition the main disconnect is in the garage, so I told my client that the panel in the house is the sub panel and grounds and neutrals should be separated. The realtor told me I was wrong that "technically" the main disconnect is at the panel in the house. I really don't give a s--t about his thoughts and think he wrong, but I thought as I'm writing this report I would ask for input from the people whose opinion I do care about.

It depends on what you mean by main breaker. As Brandon pointed out, after the service disconnecting means, the neutral isn't supposed to be connected to the equipment cabinets or to grounding conductors. (250.24(A)(5))

- Jim Katen, Oregon

[JohnC]

Thanks Jim!

JohnC

[Chad Fabry]

I've never seen 12 AWG stranded aluminum before... that wire is stranded isn't it?

[JohnC]

12 AWG stranded aluminum it is, which I have never come across before,1st time for everything.

John Callan

[Jim Katen]

12 AWG stranded aluminum it is, which I have never come across before,1st time for everything.

John Callan

I don't think so. Are you sure it isn't copper wire that someone tinned with solder?

[JohnC]

Hey Jim,

It sure looks like Aluminum to me, but I haven't come across copper wire tinned with solder before. Is this something you see a lot?

John Callan

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[Richard Moore]

Tinned stranded copper wire is commonly used, pretty much required, in marine environments (read boats). It prevents the copper from corroding from the harsh elements. The flexability stops it coming loose from vibration (along with crimp connectors). The whole wire comes like that. IE...no one just tinned the ends.

I suspect the homeowner just had some lying around. No harm using it as far as I can see.

[Chad Fabry]

I used to use a product designated AWM? that was finely stranded and highly flexible. I got it off military stuff. I don't know what the conductor is made of but it can't be soldered. I'll rummage around in my basement later an d get the type off the insulation.

Anyway, that's what I thought the wire in John's picture looked like.

[Jim Katen]

Tinned stranded copper wire is commonly used, pretty much required, in marine environments (read boats). It prevents the copper from corroding from the harsh elements. The flexability stops it coming loose from vibration (along with crimp connectors). The whole wire comes like that. IE...no one just tinned the ends.

I suspect the homeowner just had some lying around. No harm using it as far as I can see.

You're probably right. The close-up picture clearly shows that the wires were coated by the manufacturer. It's not aluminum, the strands are much too fine.

- Jim Katen, Oregon

[John Kogel]

I suspect the homeowner just had some lying around. No harm using it as far as I can see.

I agree, we think the wire can carry 15 amps OK.

But whether it can or not, I would call for repairs by a qualified electrician.

All that double-tapping points to, like you say, amateur at work, possible hidden hazards, etc.

Even if it was single strand Cu I'd be calling for repairs. An electrician will find something wrong in there.

[Jack Davenport]

as per the national electrical code you can only have 1 neutral conductor pr terminal. As far as the number of grounds per terminal , you will need to read the panels label as this is where that information is located. It should tell you how many and what sizes you are to have per terminal.

[john_opwin]

Regarding your problem you have to use Aluminum wire that has low receptivity conduction.