Interior terminal connection

Sorry but I cannot wrap what the hell I need to here with the 83% rule.
175A disconnect, the wires are 2/0 al & same to interior dist panel.
The interior terminal connection looks like this & THANK YOU!


What are you wanting to know?

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Is 175A OK for 2/0 al
Thanks Sir Roy!

Simply. No.

Were those hot at the inspection? That is some serious damage.

You need at least 3/0 AL for 175 breaker, here is the math:

175 breaker * 0.83 = 145.25amps is the minimum conductor To determine the gauge, turn to table 310.15(B)(16) and you will see AL 2/0 in 75C column is only rated for up to 135, so you have to jump to 3/0AL rated for 155amps

Another example: 200amp breaker * 0.83 = 166amp min conductor, so we jump to 4/0 AL (rated up to 180amps) because 3/0 AL is only rated for up to 155amps, that’s how the old chart was determined (what Michael posted). The new NEC relies on the 83% rule, the old chart was removed.

Size does matter, gents! :smiley:

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THANKS Michel.
When I see stuff like this sometimes I scratch my head & wonder if I’m on candid camera.
The damaged cables were 86* today.
The clothes dryer, etc were not all on at once.
I really didn’t want to turn everything on for an experiment.
Original installation from 1978.

Do you really think that the load on that panel was greater than the #2/0 conductors or was it a connection failure at the terminals?

I think it’s the connection but not sure.
There was also water intrusion/rust evidence on top, most likely from the old roof that was recently replaced.


Have a qualified electrician repair/replace all of that.
No sense diagnosing all that mess.