480/277v 3phase

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pkrupski

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Mountain Top, Pa. USA
I have service from utility that is 3 phase 480, I only need 480-no 277 at all. Panels I'm using are 3 phase 480/277. By code, do I need to pull a neutral to panels even though I will never need the 277? Thanks in advance for any info.
 
Here is the code section.

250.24(C) Grounded Conductor Brought to Service Equipment.
Where an ac system operating at less than 1000 volts
is grounded at any point, the grounded conductor(s) shall
be routed with the ungrounded conductors to each service
disconnecting means and shall be connected to each disconnecting
means grounded conductor(s) terminal or bus. A
main bonding jumper shall connect the grounded conductor(
s) to each service disconnecting means enclosure. The
grounded conductor(s) shall be installed in accordance with
250.24(C)(1) through (C)(4).
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There are no requirements to bring the neutral any further.
 
I have more info that raises a further question. The panel I'm using is a square d nf 600/277v 3 phase 4 wire. Again, no loads other than 3 phase 480v. No neutral pulled to panel. I'm being told the panel is not being used in accordance with manufacturers intent and therefor it becomes a liability issue, not an electrical or functionality issue. Does anyone know what the liability is? What problem could arise that would trigger this liability? Thanks.
 
pkrupski said:
I have more info that raises a further question. The panel I'm using is a square d nf 600/277v 3 phase 4 wire. Again, no loads other than 3 phase 480v. No neutral pulled to panel. I'm being told the panel is not being used in accordance with manufacturers intent and therefor it becomes a liability issue, not an electrical or functionality issue. Does anyone know what the liability is? What problem could arise that would trigger this liability? Thanks.
Click to expand...
What?!!! Is the panel only meant for line to neutral loads? I don't think so. Voltage to ground is the same with a neutral there or not.

Who is giving you all this grief?
 
pkrupski said:
I have more info that raises a further question. The panel I'm using is a square d nf 600/277v 3 phase 4 wire. Again, no loads other than 3 phase 480v. No neutral pulled to panel. I'm being told the panel is not being used in accordance with manufacturers intent and therefor it becomes a liability issue, not an electrical or functionality issue. Does anyone know what the liability is? What problem could arise that would trigger this liability? Thanks.
Click to expand...

I have seen the NF marked 600 volts on the label as well - don't know why, they only make breakers rated 480/277 for that line AFAIK.

But whether it be 600 or 480 that is the max voltage not the only voltage it can operate at. You could use this panel for 208/120 if you wanted to, but going to the QO series would (should) cost less.
 
If the system voltage is 277V maximum, you can use the NF panel. There is no need to have the neutral in the panel itself.
 
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