Thread: Aluminum in a cloth jacket?

We need a new one to kick around, so here goes.
This was a 1959 house, so I was a bit choked to see solid Al branch circuits. I think the basement circuits were added in the 60's, maybe.
Can anyone date these cables by their green cloth jackets?
Maybe that's not aluminum?
The panel is a Federal Pacific, yes, I know. It is a Canadian FPE with the copper busbars. The newer breakers have no known issues, believe it or don't.

An electrician will be going out to make repairs as he sees fit. What would the sparkys here suggest, and no, the client can't afford to upgrade yet. Just make it safe for a couple more years. What would you do?

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I can't help you with the green jackets, however, are you sure it wasn't tinned copper wiring?

John,

Is that panel the service equipment panel or a distribution panel downstream from the service equipment panel? If service equipment, is that a split bus panel?

AFAIK AL cables all had plastic sheathing. I have never even heard of someone having seen cloth sheathed AL.

I saw a lot of AL wire in those green jackets. Although it can be special ordered, it is very uncommon to find tinned wire with thermoplastic insulation. This stuff also has the "look" of aluminum. It appears to be something added after the initial panel installation.

If it is in fact aluminum, the neutral buss bars aren't listed for it and would need to be pigtailed. It looks like the back buss isn't being used and there "might" be enough spaces to terminate the neutrals and grounds - assuming this is a service panel ( I think I see a separation from the top area where there might be a service disconnect.

If not a service panel even more work is needed.

FWIW, I find the breaker busses on these panels to be as big an issue as the breakers so no free pass on that even for a "northern version" of this classic junk

Unfortunately; I see no practical, ( that would be legal ), way to escape a new panel. The panel is all copper, ( not copper / aluminum ), so there really is no legal place to terminate the alum. conductors. There are multiple conductors in lugs/terminations not approved for same and there are copper and alum. wires illegally mixed together. This part is not for codies and none us us could legally recommend this. The only alternative I can see to no new panel, ( not legal, but functional ), would be to use small / mini, ( cu/al rated ), neutral and ground bars as splices. Terminate the alum neutral and ground wires on them and add a copper jumper from them to the panel copper buss bars.

Originally Posted by Jerry Peck

John,

Is that panel the service equipment panel or a distribution panel downstream from the service equipment panel? If service equipment, is that a split bus panel?

It is a service panel, as is usual up here. The disconnect is always indoors. There's one more screw at the top I wasn't able to get to inspect the SEC and grounding. Canadian panels have the SECs separated by a barrier.
No not a split bus panel. The two buses have alternating slots for the full length.

Originally Posted by Bill Kriegh

I saw a lot of AL wire in those green jackets. Although it can be special ordered, it is very uncommon to find tinned wire with thermoplastic insulation. This stuff also has the "look" of aluminum. It appears to be something added after the initial panel installation.

If it is in fact aluminum, the neutral buss bars aren't listed for it and would need to be pigtailed. It looks like the back buss isn't being used and there "might" be enough spaces to terminate the neutrals and grounds - assuming this is a service panel ( I think I see a separation from the top area where there might be a service disconnect.

FWIW, I find the breaker busses on these panels to be as big an issue as the breakers so no free pass on that even for a "northern version" of this classic junk

Thanks, Bill. And Garry.
I was confident it was Aluminum but I was questioning it this AM, looking at the pics.

Good point about the bus not rated for Al. They should just replace those branch circuits and remove the issue.

I ran into this scenario earlier this year, 1955 house, all grounded receptacles, Al branch circuits that time were in silver cloth jackets.

Pic 1 is this panel, pics 2, 3 and 4 are the place I did in the spring, similar discoveries.

Something that shows up in the second picture are the "nicks" made by someone stripping the wire without using the right tool. In all wire, but especially aluminum, these nicks translate into a break very easily with a bit of movement. Ought to be a flogging offense.

I see aluminum grounding conductors, but somehow I don't see any aluminum neutrals. I have seen NM with aluminum neutral and copper current carrying conductors rarely. Not sure if it was common in other parts of the country.

At least your second set of photos have cu/al alloy buss bars. One way you can tell a panel has been around a while is the wire bending space, ( in this case lack of it ). That is tight ! Horizontal wires entering the can being met head on by horizontal wires from the C/Bs and not enough space in between.

Originally Posted by John Kogel

It is a service panel, as is usual up here. The disconnect is always indoors. There's one more screw at the top I wasn't able to get to inspect the SEC and grounding. Canadian panels have the SECs separated by a barrier.
No not a split bus panel. The two buses have alternating slots for the full length.

Your new photos shows the service disconnect which was not shown in the first photo ... without that service disconnect in the photo it looked like service entrance conductors coming down, now I know they are feeders. Full length photos showing all sure do make a difference.

Originally Posted by Gunnar Alquist

I see aluminum grounding conductors, but somehow I don't see any aluminum neutrals. I have seen NM with aluminum neutral and copper current carrying conductors rarely. Not sure if it was common in other parts of the country.

It is not common, but I think that is what we have here in panel #1.
When I tried to trace the blacks back to the breakers, I saw copper.

Originally Posted by John Kogel

Can anyone date these cables by their green cloth jackets?
Just make it safe for a couple more years. What would you do?

That's definately aluminum & I'd peg it at or around the late 70's.

My typical recommendation would be for their electrician to check all splices to ensure theyre tight, not quick-connected at all devices, ensure proper use of anti-oxidant paste or connectors where needed and to pig-tail to any device not rated for use with aluminum wires. That should keep it all safe for many years to come.

I expect many to chime in with all kinds of attacks here but aluminum wiring has been functioning well for the last 45 years and yes there have been many fires as a result, probably most (if not all) were as a direct result of the conditions mentioned in my previous paragraph. Most home handymen adding to existing circuits don't understand aluminum has a much different temperature co-efficient than copper, which causes greater expansion / contractions, resulting in loose connections. Aluminum just doesn't accept the same installation sloppiness as copper.

An example of sloppiness would be the small circular nick into the conductor (look at the aluminum neutral conductors) which is most often caused by using one of those cheap wire strippers with the sliding set-screw. Once nicked like that, aluminum wire will just snap off if bent back & forth once or twice and under certain conditions can become a hot spot, where as copper is a little more forgiving.

Thanks, Joe. I was hoping to date the green cloth cable with two copper conductors and one aluminum ground wire. I think the cloth and paper wrap is from the 1960's.

Sometimes we see cloth wrap used in the 70's but it's probably someone using up old stock. At least that is my take on it.