How many service the building has? the number of service disconnecting means

[dahualin]

I am doing a project with a big cooler warehouse building and a big freezer warehouse builidng. They are connect to each other. I believe they are separated by fire rated wall. The owner owns the primary service including 12kv primary utility meter and switch, 2500KVA 12kv/480v transformer for the freezer building and 1000KVA 12kv/480v transformer for the cooler building. Primary utility meter and swtich, transformers are located outside the building. I am not sure how many service we got. For the whole site, it is one service from utility company. But for the building, it seems two service one from each transformer.
If the site as a unit and it has one service, how many service disconneting means are allowed to be installed on the whole building? How does the six disconnect rule apply to the building? Thanks.

 

[raider1]

It sounds like there is one service from the utility at 12Kv. After that each building is fed by a feeder. Take a look at 230.70 for service disconnecting means, and 225.30 and 225.31 for the feeder requiremements for each building.

Chris

 

[RB1]

David,

My answer is based on the primary switch beling located remote from the building.

It appears from your description that you have one service (12KV). The conductors from the secondary of the transformers to the building(s) are feeder conductors. If there is a fire wall that provides separation between the two buildings there is no problem supplying each building with it's own feeder (225.30).

As transformer secondary conductors the rules of 240.21(C) apply. If the length of the conductors exceeds ten feet, a single disconnecting means is required at each building, that is, unless this facility meets the definition of a supervised industrial location, in which case up to six disconnects would be permitted (240.90(B)(2)(2)).

 

[dahualin]

I am reading article 230 - services. Could anybody explain Exhibit 230.4 "One service. One service drop supplying two service equipment enclosure installed at separate location, each with maximum of six disconnecting means" and Exhibit 230.13 "One service. One service laterial supplying four service enclosure permitted to have a maximum of six service disconnecting means." on 2005 NEC handbook? It seems to me one service can have more than 6 service disconnecting means in total if there are more than one service equipment enclosure installed at different locations.
Compare Exhibit 230.10 with Exhibit 230.12, why it is one service on Exhibit 230.10 and two services on Exhibit 230.12?
Thanks.