Re-feed existing panel w smaller feeders - need to remove main CB?

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aforni

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A new service is needed for an existing commercial building due to service feeder routing issues. The existing main service switchboard will be re-fed from the new service and will become just a distribution board. The meter will be removed.

This existing board is rated 1200A with a main 1200A breaker. But the board, based on utility data, does not pull more than 200A. Of course this based on 15min averaging...and there is an elevator...so to be safe, and based on the old load calcs, we are re-feeding with 800A feeders. The new service is just 1000A.

Question: does that main breaker NEED to be removed? I don't see anything positive or negative in 408, 240, etc, but it seems like it shouldn't be there. Though, obviously this breaker will probably never trip since its protected by 2/3 the ampacity.

If we need to "fuse" the busses, has anyone done something like that? How are the bussbars merged? Would the mfg need to be involved to preserve the listing?

Thanks for your time on this brainteaser guys.

Adam
 
The breaker can remain as long as your new feeder conductors are properly sized and protected at the new service there should be no problem.
 
aforni said:
A new service is needed for an existing commercial building due to service feeder routing issues. The existing main service switchboard will be re-fed from the new service and will become just a distribution board. The meter will be removed.

This existing board is rated 1200A with a main 1200A breaker. But the board, based on utility data, does not pull more than 200A. Of course this based on 15min averaging...and there is an elevator...so to be safe, and based on the old load calcs, we are re-feeding with 800A feeders. The new service is just 1000A.

Question: does that main breaker NEED to be removed? I don't see anything positive or negative in 408, 240, etc, but it seems like it shouldn't be there. Though, obviously this breaker will probably never trip since its protected by 2/3 the ampacity.

If we need to "fuse" the busses, has anyone done something like that? How are the bussbars merged? Would the mfg need to be involved to preserve the listing?

Thanks for your time on this brainteaser guys.

Adam
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It would be helpful if you provided some details about the breaker. Nameplate data, trip unit data, etc..
 
There is absolutely no requirement that prevents a downstream device from having a larger ampere rating than the device feeding it.

Most probably, the biggest issue will be terminating 200A conductors into 1200A lugs.
 
I don't see any reason to mess with it. The wires are protected by the OCPD where the wiring originates. Think of it as a nonfused disconnect.
 
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