Switchboard Main Breaker

J

Jimmy7

Senior Member
Location
Boston, MA
Occupation
Electrician
The owner of a project we’re working on hired their own engineer to review the proposed drawings. Currently, drawings show a SWBD-Main labeled “Service Disconnect”, and there is also separate switchboard labeled “SWBD-Dist”, both switchboards are in the same building. On the schedule SWBD-Dist is listed as Main Lug Only. The owner’s engineer is stating that the SWBD-DIST requires a main circuit breaker. I don’t think a main breaker is needed, am I correct on this?

This engineer also is suggesting that the generator switchboard (SWBD-Gen) have a main breaker as well. This switchboard currently only has the ability to have six breakers maximum. Since it can only have six breakers a main wouldn’t be needed, correct?





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The 6 circuit is typically applied to the Service Entrance and Transformer Secondary locations, and more recently when entering remote buildings.

A main breaker can be located (i.e. remotely) anywhere upstream from the equipment it protects.

If all of your equipment is in one room, your SWBD-DIST does not need a local main.
 
jim dungar said:
If all of your equipment is in one room, your SWBD-DIST does not need a local main.
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Am I missing something here? I'm not aware of any requirement for the main for a distribution panel to be in the same room as the dp.

At any rate, IMO, even if its not a code issue, if the client wants a main in that panel to make maintenance easier, they would get it (assuming they are paying for it.)
 
steve66 said:
Am I missing something here? I'm not aware of any requirement for the main for a distribution panel to be in the same room as the dp.

At any rate, IMO, even if its not a code issue, if the client wants a main in that panel to make maintenance easier, they would get it (assuming they are paying for it.)
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Money is the issue here. The engineer came late to the game and wants to add the mains. The concern is that by adding the mains will the size of the gear increase, and will it cause the need for the rooms to be larger. The drawings were already complete…
 
steve66 said:
Am I missing something here? I'm not aware of any requirement for the main for a distribution panel to be in the same room as the dp.
Click to expand...
Being in the same room is not a requirement. As I said in my post, the main can be mounted remotely. In remote buildings a local main is often required.

By being in the same room there is no interpretation of the NEC that would require a main breaker in the OP distribution switchboard.
 
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