Carultch
Senior Member
- Location
- Massachusetts
I have a situation with a 400A Fused disconnect tapped to a 1200A feeder.
The load side feeder of the 400A disconnect extends a significant distance, so it is of interest to reduce its wiring as much as practical.
I understand that where the EGC is routed with the tap conductors, it has to be sized to the 1200A feeder, rather than the 400A disconnect. Thus #3/0 instead of #3. 250.122(G)
I also understand that when the neutral carries negligible current, its minimum size is the size of the EGC. 215.2(A)(2)
In this example, neutral is insulated from ground in the 400A fused disconnect.
See my example in the attachment.
Would I need to run a 3/0 neutral with the tap conductors, and then splice in the disconnect to a 2/0 neutral for the distant feeder?
Or would a 2/0 neutral suffiice everywhere.
The load side feeder of the 400A disconnect extends a significant distance, so it is of interest to reduce its wiring as much as practical.
I understand that where the EGC is routed with the tap conductors, it has to be sized to the 1200A feeder, rather than the 400A disconnect. Thus #3/0 instead of #3. 250.122(G)
I also understand that when the neutral carries negligible current, its minimum size is the size of the EGC. 215.2(A)(2)
In this example, neutral is insulated from ground in the 400A fused disconnect.
See my example in the attachment.
Would I need to run a 3/0 neutral with the tap conductors, and then splice in the disconnect to a 2/0 neutral for the distant feeder?
Or would a 2/0 neutral suffiice everywhere.
Attachments
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