Feeding subpanel

I inspected a house today that had a 100 amp subpanel in the basement being fed from the main service panel in the garage. The large wire coming from the sub panel is hanging loose in the main panel & has I think # 12 spliced & taped up (1 white & 1 Black)& then tapped into a double wide breaker. Any comments?

Now after looking closer at the pictures, it looks like the larger subpanel wires got to the double wide 100 amp breaker at the top left corner.
So I am still wondering about those loose spliced wires on the lower left side?

With 75 degree C connections, aluminum wires not carrying an entire dwelling service have to be at least #1 AWG for 100A. A better answer is only possible if I get the guage and listing code from the outer jacket of the cable, and all conditions of use.

The splice up in size was probably done for voltage drop or derating. As long as the double pole breaker is no bigger than 20A it’s code. (But not my style. I prefer to label the wires “max 20A breaker, derating.” Then land the larger wires directly on the breaker. If it’s within the lugs listed capacity.)

This #12 white wire used as a hot is a code violation. It is not in one of the exceptions. But it is a very minor violation, not worth fixing. I would be less forgiving if he did the same thing anywhere else in that circuit.

Hi Mr. Moderator. Did my earlier post get lost? Thx, glenn


Since it looks like #10 AWG on a 30 amp CB it fine depending on the connected load. As mentioned the re-identified white is NG.

Thanks Robert. I couldn’t read the breakers or see the wires clear enough on my iPad. I was going by Roy’s statement that the wires were #12 for my 20A spec.

Those 2 wires do look bigger than the rest so maybe they are #10

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