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Senior Member
I have main service switchboard that has 8 service breakers and no main breaker.

5 service breakers have existing feeders go to existing loads in building and are already wired to the loads i.e existing, 6th service breaker is spare and now going to have new loads, new feeders from breaker to new load and 7,8 are spare breakers nothing connected no load


1. in the above scenario since their is no main breaker at service switchboard would adding sixth breaker new feeder new load require main breaker or not?

2. I heard some require if its more than 5 service breakers but the way I read is 6 max meaning more than 6 but not sure and want to confirm. Also I am confused because main switchboard 7,8 have breakers but they are spare would they count in determining NEC 2014 section 230.71(A)?
read 230.71
6 max
spares count
I am not so sure spares count. There is not a specific detailed definition of ":service disconnect" but 230.70 says:

230.70 General. Means shall be provided to disconnect all
conductors in a building or other structure from the service entrance

If there are not conductors landed on them then it seems there is nothing to disconnect. Some may say the load side lugs are conductors, but the definition of Conductor, Insulated, and 310.1 does not seem to support that view.
I come at it from the use direction- if the purpose is to quickly disconnect all electrical energy to a building, the person doing won't really know if they're in-use/connected or not. One could make an argument that if they're obviously locked off, they might not count, but I wouldn't hang my hat on that one.


Senior Member
Northern illinois
I would suggest this is not a well-defined situation code-wise. I don't see anything in the code that actually says specifically one way or the other. Personally I Wonder why somebody put spares in the first place. They had to know there was no other disconnecting means.

On the other hand just having spare spaces somebody might argue somebody could put another breaker in there and violate the code down the road. I don't think there's any code provision that says you have to prevent someone from doing something wrong down the road.

Without a definitive answer from the code I would say the spares are okay. The breakers are there to disconnect circuits. If there's nothing connected to them there's no circuit.
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