Rule of Six ? (230.40; 230.71)

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Jbeighey

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NEC 230.40; 230.71 sets a limit of not more than six service disconnecting means for a single set of service entrance conductors grouped at one location. Does this apply to a single building which has eight separate addresses, each individually metered, and each is divided by a fire rated wall. Do multiple occupancies for a single building have any bearing on this rule?

Thanks,

Jerry
 
You are generally limited to 6 or fewer handles regardless of the number of tenants. After 6 you install a main. There are some exceptions, but having 8 tenants isn't one of them. Review 230.2 for specific information.

If the fire walls have sufficient rating, you could move the meters and disconnects to each tenant space and not group them if the POCO is good with it. It will require that each fire wall create a separate building though.

Jim T
 
Related question: They could be separated into two groups of four, but exactly how far apart do disconnects have to be to be not considered 'grouped'?
 
Each set of service entrance conductors can have a set of six disconnects. Each occupancy has a set of service entrance conductors. There is no requirement that the disconnects for one set of service entrance conductors be grouped with the service disconnects for any other set of service conductors.
Don
 
don_resqcapt19 said:
Jerry,
Where are the service disconnects located?
Don
Click to expand...


The original design was to include a service tap can, which would be fed from the local utility transformer. A gutter system would then be connected to the tap can for a meter tap for each tenant. The service switches would then be mounted directly after the meters all in one line-up. This is what caught my attention, because we now would have more than six switches in one group.

Everything that I have read seems to address a single occupant building with only a single means of metering. The large building in question has fire rated walls dividing each tenant, which would lead me to believe that we now are dealing with eight separate buildings. I don?t know if this is going to change the grouping of six within the code.

Some information that I took from another source went on to explain that we should install a main switch ahead of the tap can to resolve this situation.

Does anyone have any thoughts on this?

Thanks,

Jerry
 
Jerry,
The code is not completely clear here. The wording in 230.71(A) is not consistant. The first part says that each service or set of service conductors can have up to six means of disconnect. In your case there are 8 sets of service conductors and up to 48 means of disconnect permitted. Then the section goes on to say that for each service there can be no more than 6 disconnects in a single location. In this part of the code they did not add the words "or for each set of service conductors" as they did in the first part of the section.
Where is the safety hazard in multiple disconnects located in a group? It is clear that I can locate the multiple disconnects remotely without a main, as long as I can comply with 230.70(A)(1). How are 8 sets of 6 disconnects installed in remote locations safer than all 48 installed in a single outside location?
Don
 
Don't get confused by the code term "service". Service is the attachment point from the power provider. USUALLY (with many exceptions) there is only one service per building. You may then run service entrance cable to each "occupancy" and proivde up to six discnnects per service entrance cable. The trick is that the service entrance cable must not enter the building until it enters the occupancy where the disconnect(s) (and OC device) will be located. We have an apartment building in this area that has done this, there are service entance cables installed on the exterior of the building to each occupancy - so the building looks a little like it is being attacked by an octopus! This may be what the designer of your building is trying to avoid - by grouping the service disconnects together, the conductors to each occupancy then become feeders and may be concealed in the building. The problem is that you then come up against the six-disconnect rule. If they want the eight service disconnects grouped together you will need a single main disconnect before the occupancy disconnects. You can't have it both ways, the conductors to the occupancy must be either service entrance conductors or feeders and treated accordingly.
 
haskindm said:
If they want the eight service disconnects grouped together you will need a single main disconnect before the occupancy disconnects.
Click to expand...
What about two disconnects supplying four tenants each, or four disconnects supplying two tenants each?
 
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