230.71(a)

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Mezani

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I have six 3000 amp 480/277 services in one electrical room. Are these grouped in one location therefore allowed only six disconnects? or is this six separate services and can have 36 total service disconnects in one electrical room?
 
I think we have a problem with terminology here. To start with, how many different sets of conductors are you getting from the utility? In most cases, you are only allowed to get one "service" into a building from the utility. In what sense are you saying you have six "services"?

Next, once power makes its way into the building, what type of equipment does it connect to? Is it terminated on a switchgear or switchboard? Are there six such switchgear or swichboards? Do they have main breakers?

The six disconnect rule has to do with the ability to turn off all power coming into a building from one location, and to do so with minimal effort. If for example you have one service that is connected to a main switchboard that has a main breaker, then you can turn off all power to the building with one throw of a handle. Within the switchboard itself, then, you can have an unlimited number of breakers serving loads throughout the building. But if the main switchboard did not have a main breaker, then it may have no more than six breakers serving loads in the building, so that you could turn off all power to the building by throwing (at most) six handles.
 
230.2 (C) allows additional services to a building. Each one is a switchboard and two have a single main and four have 2 to 6 main disconnects. One room 6 services total 13 service disconnects.
 
By 230.2 the building is allowed to have multiple services, my thoughts are it should be limited to 6 disconnects in the main electrical room. I am looking for others thoughts. What guidelines are referring to?
 
Mezani said:
By 230.2 the building is allowed to have multiple services, my thoughts are it should be limited to 6 disconnects in the main electrical room. I am looking for others thoughts. What guidelines are referring to?
I have to disagree. Look at 230.71 (A). Each separate service is limited to six disconnects. You have six services, therefore you are limited to 36 disconnects. So your 13 does not violate the rules.
 
charlie b said:

I have to disagree. Look at 230.71 (A). Each separate service is limited to six disconnects. You have six services, therefore you are limited to 36 disconnects. So your 13 does not violate the rules.

I agree with Charlie. Each service would have to be clearly labeled per 230.2(E).

Pete
 
Mezani said:
What about "There shall be not more than six sets of disconnects per service grouped in any one location"?

In your example you could have "six sets" of six.

Pete
 
Mezani said:
What about "There shall be not more than six sets of disconnects per service grouped in any one location"?
Did you not notice the words "per service" in your quote?
 
charlie b said:

I have to disagree. Look at 230.71 (A). Each separate service is limited to six disconnects. You have six services, therefore you are limited to 36 disconnects. So your 13 does not violate the rules.


I agree with Charlie. But what are you doing that requires 18,000 A @ 480v. I would think that something that big would have the services spread out at different places in the building.
 
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