Service disconnects

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lrollo

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I understand the ruling for service disconnects being located in the same location and not more than 6 grouped together. I have an instance where a building is under single management, has a privately owned substation, and has a maintenance department. This existing building has a main distribution panel feeding the building from a transformer. This transformer is fed by a high KV Switch. The facility added a chiller plant for cooling, they added another transformer, and a second high KV switch beside the first. The inspector is telling us we must have the two separately derived system disconnects grouped together. 3/4 the building is disconnected by the first MDP and the other 1/4 by the second MDP in another part of the building. The questions I have are:
#1. Wouldn't the 2 High KV switches be considered as a disconnecting means for each part of the building?
#2. If there are documented safe switching procedures established and maintained for disconnection, and the establishment is monitored by qualified personnel (such as the manitenance department), Wouldn't this be an exception to the disconnecting means being grouped in the same location? If not would these documented procedures allow the high KV switches to be used as the disconnecting means? The section I am reading is 225.32 Exc. #1
 
Re: Service disconnects

Lrollo,
If I understand your post correctly, you are working in one building. 230.2 states a building or other structure served shall be supplied by only one service unless permitted in 230.2(A)through(D) So are you applying 230.2(B) or 230.2(C)? I would think even if you could apply 230.2(B) you would still have to apply 230.70(A), 230.71(A) and 230.72(A)

I can only find 230.72(B) allowing additional services to be remote from the normal service.
225.32 EX.#1 IMO only applies when you have more then one building or structure on the same property being supplied.
I am only an apprentice so we should wait and see what others with more experience say. I am sure the question of "What defines grouped?" will come up....

[ January 25, 2006, 03:54 PM: Message edited by: kevinware ]
 
Re: Service disconnects

Effectively each transformer secondary is it's own service. There is no requirement that these secondaries be grouped together.

It is very common to distribute medium voltage throughout a facility and then locate substation transformers near the loads.
 
Re: Service disconnects

If I also understand your post, the 2 HV or MV switches are owned by you and fed from the utility, correct ? And then they feed 2 transformers, presumably MV to 480/277 or some such utilization voltage. IMO, the feed from the utility is the "service entrance" and the 2 switches are the "service disconnects". Everything else is / are feeders, etc.

Sounds like your service disconnects are grouped together and fall under the 6 switch rule.

Agreement ? Disagreement ?
 
Re: Service disconnects

Yes, the substation, the MV switches, the transformers, everything except the incomming feed to the substation is owned by the customer. the 13,800 comes from the substation to a switch and from that switch it is distributed to one transformer 13,800 primary-480/277 secondary.From that transformer it feeds one MDP in the building. There is a second Switch fed with 13,800 volts which feeds a second transformer which feeds a second MDP in the same building. The 2 MV Switches are sitting side by side. Can these two switches be considered the service disconnecting means for the building and what part of the code will support this?
 
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