I'm installing a 400 amp 3 phase panel from a 480/277 switchboard located in another building. The panel is going to supply strictly 3 phase power loads only. Because a neutral is available in the switchboard, Am I required to install one when I pull the feeder cables in even if there are no single phase loads? If so, what size? Thanks, Dave
Grounded conductor required?
- Thread starter djuntunen
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pierre
Senior Member
- Location
- Westchester County, New York
Re: Grounded conductor required?
How are the lights and receptacles in the separate building supplied?
Pierre
How are the lights and receptacles in the separate building supplied?
Pierre
Re: Grounded conductor required?
In the building there is currently a single phase panel for lights and outlets and Three phase 240v for power. These 2 panels are fed from the seperate bldg. where the 480v switchboard is. The new equipment I'm installing requires 480v.
In the building there is currently a single phase panel for lights and outlets and Three phase 240v for power. These 2 panels are fed from the seperate bldg. where the 480v switchboard is. The new equipment I'm installing requires 480v.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: Grounded conductor required?
The size of the grounded (neutral) conductor is based on the maximum unbalanced neutral current (per Art 220) or table 250.66 which ever is larger.
Also both systems in that building will be required to use a common grounding electrode system.
You will also have to install an equipment grounding (bonding) conductor.
The size of the grounded (neutral) conductor is based on the maximum unbalanced neutral current (per Art 220) or table 250.66 which ever is larger.
Also both systems in that building will be required to use a common grounding electrode system.
You will also have to install an equipment grounding (bonding) conductor.
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