Panel box wiring..Question

The main panel had larger wires connected to smaller wires with wire nuts

and duct tape…like a 10 awg to a 20 awg. Is this acceptable ? What

type of write up would be appropriate ?

Are you sure it was 20 awg? That would be too small for any circuit.

Wire nuts in the panel are not an issue. Down sizing the wire can be acceptable depending on the size of the breaker attached to the conductors.

thanks Jeff…I meant to say…a 10awg to a 12awg…I was thinking of 20amp
breaker…Thank God for Nachi…

Yes, the OCPD would need to be rated for the smallest conductor on that circuit even if those splices were not within the panel. So you could leave the panel with a #10 AWG conductor and splice a #14 conductor AWG to it some where down the line. The OCPD would then need to be 15 amps. As Jeff stated splices are fine due to NEC 312.8.

This completely correct. You can downsize the wire as long as it is on the proper breaker for the smaller size wire.

David- when I see larger conductors spliced to smaller conductors in a panel like that it raises the “aluminum wire” red flag. That’s not always the case, but I’ve found it more than a few times. Just a thought.

So what would be your concern the wire connector type?

I would assume the major concern is the possibility that this would be an indication of the the presence of otherwise unsuspected aluminum banch circuit wiring.

Got it. So pigtailing a piece of copper at the CB would make you think that the structure may have small aluminum branch circuit wiring.