Automatic transfer switch protection for diesel generator

[rootanp]

I am installing a diesel generator outside a building. The generator has a breaker located at the generator. Do I have to install any other circuit protection before the automatic transfer switch? The transfer switch is located inside the building in an electrical room.

 

[dpc]

No, you should be fine as long as the feeder from the generator to the ATS is sized such that it is protected by the generator breaker.

 

[NYedison]

The breaker with diesel generator is generally designed and set for the protection of the Generator.

Beoyond the ATS, existing downstream breakers take care of the fault on load side. You may not need any additional protection.