One service with multiple tenants

[jkim780]

Question on multiple metering with service disconnets. Here is the situation.

a 4-story building. There will be multiple tenants on each floor, probably 8 to 9. I am going to have a 2500A 120/208v service for the building. My design is following.

One service lateral from utility xfmr to a 2500A swbd on the first floor. The swbd will have (5) circuit breakers without a main. I am intending to use this as service disconnects per six disconnect rule per 230.71. Each circuit breaker feeds a termination box on each floor which will feed a meter bank (up to (9) meters)for multiple tenants on that floor.

For example, a 800A circuit breaker at switchbord will feed a 800A termination box on the second floor. Off of that termination box, there will be a meterbank with (9) meters for multiple tenants. Each meter will have a tenant circuit breaker.

Now my question is

1) Is this complied with the code?

2) Can I have (1) remote service disconnect with multiple meters like I intended?

3) Or Should each tenant circuit breaker be considered as a service disconnet? If this is the case, should the meter bank be limited to 6 at each location per 230.71 (six disconnect rule)? Then I will have to have two meterbanks at each floor.

I appreciate your responses in advance.

[ October 18, 2005, 10:53 AM: Message edited by: jkim780 ]

 

[charlie b]

Re: One service with multiple tenants

The six disconnect rule ends at your five breakers in the switchboard. You don't have to limit all downstream connections to 6 disconnect devices. One breaker can feed 9 meters/tenant disconnects. But at that point I think you are dealing with feeders, not services.

Also, that meter bank (9 meters, each with a disconnect) has to be accessible to the tenants. Either it must be in an unlocked room, or the building management has to be available 24/7/365 to give each tenant access to their disconnecting means. Reference 230.72(C).

 

[bphgravity]

Re: One service with multiple tenants

1. On the surface, your brief description looks okay.

2. I don't see where you have a remote service disconnect. You have the 5 service disconnects at the service entrance, all others are feeder disconnects.

3. no

4.

 

[bphgravity]

Re: One service with multiple tenants

Originally posted by charlie b:
...or the building management has to be available 24/7/365 to give each tenant access to their disconnecting means. Reference 230.72(C).

I don't think that rule is intended to require the management to provide access to the tenants but rather access to authorized personnel only.

On a side note, the supervision would only be required for 3 hours or more. (continuous )

 

[jkim780]

Re: One service with multiple tenants

Now I am confused a little bit. Some how I thought a service disconnect is associated with a meter.

Originally posted by charlie b:
..... But at that point I think you are dealing with feeders, not services.

Also, that meter bank (9 meters, each with a disconnect) has to be accessible to the tenants. Either it must be in an unlocked room, or the building management has to be available 24/7/365 to give each tenant access to their disconnecting means. Reference 230.72(C).

230.72(c) says,
...each occupant shall have access to the occupant's service disconnecting means.

If the tenant disconnect switch by the meter is not a service disconnet, just a feeder disconnect, then shouldn't the tenant be accessible to first floor swbd, not to the meter bank, since that is a service disconnet?

That being said, if one of the tenant need to shut off the service for any reason, then wouldn't the other (8) tenants loose their service as well?

Originally posted by bphgravity :
2. I don't see where you have a remote service disconnect. You have the 5 service disconnects at the service entrance, all others are feeder disconnects.

I meant a circuit breaker at swbd as a remote service disconnect since it is not with the meter bank.

[ October 18, 2005, 12:33 PM: Message edited by: jkim780 ]

 

[charlie b]

Re: One service with multiple tenants

Originally posted by jkim780: 230.72(c) says, ...each occupant shall have access to the occupant's service disconnecting means.

I was wondering whether anyone would pick up on that use of the word "service." I think this is a bit of sloppiness on the part of the NEC authors. The word "service" is being used in two different contexts, with no hint that there is a difference between the two.

In one context, there are services, and there are feeders, and there are branch circuits. The service ends at some point that is usually determined by the serving utility. Any conductor downstream of the service disconnecting point is either a feeder or a branch circuit. In this case, the wires from the meter center to the tenant's panel comprise a "feeder," and not "service conductors."

In the other context, the tenant does not know or care how the electricity makes it to their panel. As far as they are concerned, they receive electrical "service." This context is in what I like to call "common, conversational English." When the NEC says they have to have access to their "service disconnecting means," it is talking about the device that will disconnect the "electrical service" from their unit, without disconnecting any body else. In this case, the "service disconnecting means" to which they must have access is the "feeder disconnect" located at their individual meter.

 

[charlie b]

Re: One service with multiple tenants

Originally posted by bphgravity:I don't think that rule is intended to require the management to provide access to the tenants but rather access to authorized personnel only.

My point was that if the management is not available at 3 in the morning on a holiday weekend, then the door cannot be locked. I have no problem with allowing the management representative to live in (i.e., sleep in) one of the units. But I have to be able to bang on the door and get someone to open the meter room to turn my power back on.

Originally posted by bphgravity: On a side note, the supervision would only be required for 3 hours or more. (continuous )

That's worth perhaps half a groan. :roll: