125 AMP Main Disconnect

[Harvey Gordon]

Can a 4AWG wire support a 125AMP Main Disconnect?

[Larry D. Kage]

Up to only 100 amp for copper, I believe and #2 for aluminum.

[Larry D. Kage]

I grabbed this from somewhere...wouldn't let me copy it so I made my own.

[Harvey Gordon]

[Paul W. Abernathy]

Harvy,

The question is....can a 125A rated panel handle a # 4 AWG CU.....answer is YES....is the # 4 AWG CU rated to handle 125A....NO....

If can use a 125A rated panel as long as it has a OCPD inside it to protect the ampacity of the wiring being used...in this case #4 AWG..and we will assume copper...since we should always assume that when guessing on wire sizes unless we notice otherwise...

remember even a 200A panel ( rated ) can be only a 100A panel if the main OCPD is only 100A...and the wire feeding it is only rated for 100A......good things to remember...

[Paul W. Abernathy]

Just remember...the weakest link in the chain MUST be protected....in this case the OCPD is actually designed to protect the wire.....many don't know that and think it is to protect the USER....NOT..........we will leave that to the GFCI's of the world...