100A Service Wired With #4 AL?

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Old 11-04-14, 11:10 PM
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100A Service Wired With #4 AL?

I got a call earlier tonight because someone had no power in half their house, melted buss. (Guess who made that panel) Anyway, the service was done in #4 Aluminum service cable. Was this ever legal, or is this another fly-by-night install? I'm just curious as the service is getting switched out tomorrow morning, they're on jenny for the night.
 
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Old 11-05-14, 12:07 AM
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It may have been legal in cold weather states for extra heat. (you know... to keep the conduit warm)

No....never legal that I know of. It's definitely aluminum right..... not silver plated copper ?
 
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Old 11-05-14, 12:15 AM
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It's Aluminium from the 70s. AL is printed right on the cable. May I also add a note that there's not a drop of noalox?
 
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Old 11-05-14, 12:29 AM
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Somehow that doesn't surprise me as I see it all the time or actually the lack of it.
 
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Old 11-05-14, 08:27 AM
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(Guess who made that panel) Anyway, the service was done in #4 Aluminum service cable. Was this ever legal, or is this another fly-by-night install?
The panel? My first guess would be Zinsco or GTE Sylvania (same thing). Regardless, it has to be an aluminum bus panel if the bus has melted. Also remember seeing some older Federal Pacific panelboards with melted installation/mounting hardware and I mean melted, there was a pile of aluminum in the bottom of the can where the molten aluminum had dripped.

No, the NEC has never allowed #4 aluminum for a 100 amp service. The use of antioxidant on aluminum connections is not a code requirement, but a good practice.

It's Aluminium from the 70s. AL is printed right on the cable.
The service must have had little load on it all these years. The cable would be some of the old 300 volt rated SEU cable.
 
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Old 11-05-14, 10:36 PM
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The panel? My first guess would be Zinsco or GTE Sylvania (same thing). Regardless, it has to be an aluminum bus panel if the bus has melted. Also remember seeing some older Federal Pacific panelboards with melted installation/mounting hardware and I mean melted, there was a pile of aluminum in the bottom of the can where the molten aluminum had dripped.

Believe it or not, it was a Copper-Bussed GE. The panel was very lightly loaded (3 15A circuits, 20A for washer, 2p30A dryer, and 2p50A range) until a few years ago when someone added a 8 space panel full of minis for all sorts of things like electric heat, jacuzzi, microwave, and I forget what else. The stab on the panel for the 50A breaker that fed the subpanel literally is missing except for a few burn marks.



And here's what it is getting replaced with:
 

Last edited by Justin Smith; 11-05-14 at 10:38 PM. Reason: Add picture
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Old 11-05-14, 11:52 PM
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The stab on the panel for the 50A breaker that fed the subpanel literally is missing except for a few burn marks.
And you are sure it was a copper bussed GE panel? 35 years ago I believe all GE panels had aluminum bus, but I couldn't swear to it. It's possible copper was an available option and I just never saw one. The copper stab was missing? I have seen a lot of aluminum bus destroyed by heat, but never seen a copper bus melted; burned, yes, but never melted.
 
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Old 11-06-14, 11:08 PM
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And you are sure it was a copper bussed GE panel? 35 years ago I believe all GE panels had aluminum bus, but I couldn't swear to it. It's possible copper was an available option and I just never saw one. The copper stab was missing? I have seen a lot of aluminum bus destroyed by heat, but never seen a copper bus melted; burned, yes, but never melted.

I took the panel home and cut the buss with a hack saw, it is tin-plated copper. The inspection sticker says March of 1980. I'll take pictures of the buss when I get time.
 
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Old 11-07-14, 06:40 AM
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I would cut or remove the plugmold and install the panel closer to the right to avoid any extra splices.
 
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