600 amp residential service

[JerryBumgarner]

I have a 600 amp residential service coming into a CT cabinet and feeding (4) 200 amp SE disconnects next to the CT cabinet. Each disconnect then feeds a 200 amp MB panel in the house. Can I use 2/0 copper from each disconnect to each panel, like you could on a 200 amp service or does it have to be 3/0?

 

[Treg the electrician]

im no expert but i would go off 310.12(a) single phase dwelling services and feeders. so 200 amps would be 2/0 for copper

 

[augie47]

The individual service conductors do not each carry the full load associated with the dwelling so they just b full size (3/0)

 

[Rick 0920]

I've done what you've proposed for residential services that were 400 amp. You're only allowed that reduction of ampacity on dwelling services
100 - 400 amp.

 

[wwhitney]

I've done what you've proposed for residential services that were 400 amp. You're only allowed that reduction of ampacity on dwelling services
100 - 400 amp.

2/0 Cu is not allowed to be protected at 200A on a 400A residential service. The 83% factor applies to conductors that supply the entire load of a dwelling unit.

Cheers, Wayne

 

[norcal]

If the load was calculated at 180A or less, for each panel could 4/0 AL be used?

 

[electrofelon]

If the load was calculated at 180A or less, for each panel could 4/0 AL be used?

Yupper