Service Entrance OCPD as Feeder Protection

[smackz]

Per the code, is it okay for the service entrance OCPD to act as feeder protection, or do I need to add in a dedicated feeder protection OCPD? That is, in the attached picture, is the 400A fused disconnect enough to protect the feeder or do I need the 400A main breaker that is shown as well?

 

[don_resqcapt19]

How long is the wire between the 400 amp fuses and the downstream OCPDs? Take a look at 240.21(B).

 

[smackz]

About 800ft but all outdoors, so I think I'm covered by 240.21(B)(5)

 

[david luchini]

About 800ft but all outdoors, so I think I'm covered by 240.21(B)(5)

I don't see why 240.21(B) would apply at all. The service entrance OCPD acts as the feeder OCPD.

 

[don_resqcapt19]

I don't see why 240.21(B) would apply at all. The service entrance OCPD acts as the feeder OCPD.

Yes, I did not phase my original post correctly. 240.21(B) would only apply to the taps from the main feeder that extend to the 3 OCPDs.

 

[winnie]

The 400A service entrance OCPD protects all of the 400A conductors, and might also be sufficient for portions of your 'taps'.

If this run is outside from one structure to another you need a disconnect at the second structure. Depending on the situation this might be your grouped VFD OCPD/disconnects, or you might need another 400A _disconnect_ (not an OCPD, because you already have that, but an OCPD might be the cheapest way to achieve this).

-Jon

 

[petersonra]

Per the code, is it okay for the service entrance OCPD to act as feeder protection, or do I need to add in a dedicated feeder protection OCPD? That is, in the attached picture, is the 400A fused disconnect enough to protect the feeder or do I need the 400A main breaker that is shown as well?

View attachment 18696

You don't "need" the 400 A CB. It might be handy though as a disconnecting means if one is needed.

if this is all outside get rid of the 400A CB and move the 400A fused disconnect downstream.