Feeder OCP protection

The feeders to the distribution panel are connected to lugs at the bottom and therefore protected by the main disconnect. Is this OK, or do the feeders require separate OCP protection?
Thanks for your help.

As long as they are adequately sized for the breaker, they’re fine.

What size are the feeder conductors and what is the main OCPD size? Also what do the feeder conductors connect to?

Thank you. The feeders (1/0 cu) are undersized for the 200-amp main breaker.
So I’m thinking they can just put in a 175 amp main. The feeders probably go to the garage distribution panel; it was blocked and I can’t get a look at it until tomorrow.

A few other things to keep in mind, depending on the feeder length a tap rule might apply meaning that the installation may be code complaint as is. Also #1/0 copper has an ampacity of 150 amps.

my cheat sheet says that for service or feeder 1/0 cu can do 175 amps???
i’ll leave it up to sparky. the feeders are probably only 2 feet long. how would that affect the situation?


There are 2 ungrounded conductors in the raceway with the feeders. Does sparky need to check that?

Other conductors can be in a raceway with a feeder, but not service conductors.

At 2’ long then one of the Article 240 tap rules could apply which means that the installation may be code compliant as is. It would depend on how the tap conductors are terminated at the other end. The #1/0 is good for 175 amps as a service entrance conductor or as a feeder that carries the entire dwelling load. Since there are OCPD’s in the panel where the #1/0’s are connected they do not carry the entire load therefore you must use the 150 amp ampacity {T310.15(B)(16)}.

Good catch, although they are permitted as Jim stated if the length of the raceway is more than 24" then derating may be required which might lower the ampacity of the feeder.