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Matthew Barnicle
10-15-2008, 10:52 AM
Service equipment is a single 400Amp disconnect and this equipment/panel box is rated for 400amps. The load side of the disconnect has two conductors going to two seperate panels. These panels have no disconnect and the equipment/panels are rated at 200Amps each according to the label. Is this allowed or do these panels need a 200Amp breaker/disconnect to protect them since they are rated at 200amp and there is a potential of 400amp coming into it?

Jerry Peck
10-15-2008, 10:59 AM
Service equipment is a single 400Amp disconnect and this equipment/panel box is rated for 400amps. The load side of the disconnect has two conductors going to two seperate panels.

Problem #1 - Those conductors are multiple tapped at the load side of the 400 amp main disconnect.


These panels have no disconnect and the equipment/panels are rated at 200Amps each according to the label. Is this allowed or do these panels need a 200Amp breaker/disconnect to protect them since they are rated at 200amp and there is a potential of 400amp coming into it?

Problem #2 - Yes, those panels need to be protected by 200 amp maximum mains, which could be in those panels.

Problem #3 - The feeders which are multiple tapped off the 400 amp main are (I am presuming here) only 200 amp rated, thus they would need to be rated for 400 amps, or, they could each be protected on their supply end with a 200 amp overcurrent device. There are some exceptions for feeder taps, but few, if any, would be applicable here.

Matthew Barnicle
10-15-2008, 12:41 PM
Thanks Jerry, exactly what I was looking for.