High voltage

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nechelp

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Michigan
An existing 13,200(13.2kV) volt service from the utility to a set of four high voltage switches, all grouped together. From these switches 13.2kV cable runs to individual stepdown transformers and they enter the building to four different switchgear locations.

Are the 13.2kV cables from the high voltage switches to the transformers considered feeders? Are the secondary conductors from the transformers to the switchgear, feeders or conductors of a separately derived system?

I am trying to determine if the switchgear requires a main breaker.
 
Jraef

Jraef

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Electrical Engineer
nechelp said:
An existing 13,200(13.2kV) volt service from the utility to a set of four high voltage switches, all grouped together. From these switches 13.2kV cable runs to individual stepdown transformers and they enter the building to four different switchgear locations.

Are the 13.2kV cables from the high voltage switches to the transformers considered feeders? Are the secondary conductors from the transformers to the switchgear, feeders or conductors of a separately derived system?

I am trying to determine if the switchgear requires a main breaker.
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What switchgear are you referring to, the 13.2kV or on the secondary side of the transformers? If on the 13.2kV side, is that the utility owned side or the owner side?
 
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nechelp

Member
Location
Michigan
I am referring to the low voltage (secondary side of the transformers) switchgear. Transformers are 13.2kV x 480/277V. The high voltage switches and transformers are all owner owned.
 
Smart $

Smart $

Esteemed Member
Location
Ohio
nechelp said:
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Is a main on the secondary side required by the NEC and if so what article/section?
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No. Table 450.3(A) Note 2 permits up to six sets of circuit breakers or fuses.

The compliance problem I see is the switches are likely the service disconnecting means, so the building is served by four feeders... which is a violation of 225.30... but the AHJ may have granted a deviation under 225.30(B), (C), and/or (E).
 
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