Multiple feeders to one building

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xguard

Senior Member
Location
Baton Rouge, LA
As designed we have a building under construction that has a 120/208 volt panel inside the building that will supply 120 volts for a small control panel that controls an air compressor and two pumps. The air compressor is rated 115 volts, the two pumps are 460 volt.

Ignoring lighting, receptacles and such in the building we have:
a 120 volt circuit from the 120/208 volt panel to the control panel.
a 120 volt circuit from the 120/208 volt panel to the combination motor starter/disconnect for the 115 volt air compressor.

a 120 volt control circuit from the control panel to the combination motor starter for the 115 volt air compressor.
a 120 volt control circuit form the control panel to the each disconnect and each motor starter coil for the 460 volt pumps.

The two 480 volt circuits that power the pumps originate from a 480 volt panel outside of the building, about 50 feet away, each having their own breaker. Should a single 480 volt feeder be brought inside the building, landed in a small panel and then go to the motor/contoller disconnects. I see where we meet 225.30 (D) for allowing there to be multiple feeders entering the building for different voltages. Are we allowed though to have two 480 volt circuits enter the building for the pumps?
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
I see where we meet 225.30 (D) for allowing there to be multiple feeders entering the building for different voltages.
Agreed.
Should a single 480 volt feeder be brought inside the building, landed in a small panel and then go to the motor/contoller disconnects.
Yes.
Are we allowed though to have two 480 volt circuits enter the building for the pumps?
No.

 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I agree with Charlie. Run one 480V feeder and set a panel and feed the pumps from there. Remember to check 250.32 for the requirements of a grounding electrode
 
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