PV Wire

I have old disconnected 100a grid which have wires that were never removed after putting in a new grid line. They are right next to my solar panels and lead to the main breaker (disconnected on both sides) close to where I'll be putting up the inverter. I already have PV wire that I was planning on running and drilling through some walls but if I could use this, that would save me a lot of time. Could I use this as PV wire and not have to route a new cable from roof to garage?

timaneo said:

Could I use this as PV wire and not have to route a new cable from roof to garage?

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What gauge are the wires? Can you read an AWG number?

How many amps, volts and distance of the proposed solar wiring?

Sorry I should have clarified that. It had 100amps grid power line coming in, so I assume rated for 100 amps. Panels are in series so 10 amps, 360v, 20ft wire.

Im curious if there’s anything else specific to PV wire? I’m not an electrical guy so not sure if wire strands or shielding are something to worry about, for example?

timaneo said:

It had 100amps grid power line coming in, so I assume rated for 100 amps.

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If the 100A capability is correct you can reverse the equation if you have the voltage (120V?) and distance.
This should let you guess the wire gauge.

10AWG or better should handle 360V for 20ft.

Thank you. Besides gauge to be able to carry the current, is there nothing else to consider? Old shielding, wire strands..etc? I saw wires can rated for high voltage, I'd be running up to 4x more DC voltage potentially than the 110v AC it was before.

Practically, yes. The SEU should be rated for 600v. You can get meter jumpers to connect the mast wire to the building wire.

But no inspector would probably ever pass such tomfoolery.

I assume the wires are in metal conduit all the way through from the entrance to the termination?

What I would be worried about is the impedance per foot. Being dc it will be straight power constantly heating and this looks like really old wire. If there are any arcs between them from cracks in the insulation they won't break like AC would. Were it me I would use those wires to pull a new set of cables.

@timselectric may have an opinion.