Labeling for 3PH-3W Panel

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lj

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I am installing a 480V 3-phase panelboard. It has a neutral bus, but no neutral conductors are required, so the panelboard will be used as 3-wire only. In this case, I believe the NEC requires a label placed on the front of the panelboard stating that it has no neutral or that it is 3-wire, but I cannot find reference in Article 408 or elsewhere. Appreciate any advice. Thanks.
 
lj said:
I am installing a 480V 3-phase panelboard. It has a neutral bus, but no neutral conductors are required, so the panelboard will be used as 3-wire only. In this case, I believe the NEC requires a label placed on the front of the panelboard stating that it has no neutral or that it is 3-wire, but I cannot find reference in Article 408 or elsewhere. Appreciate any advice. Thanks.
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I'm not sure you'll find one. I haven't heard that before.
 
I agree with Chevy,

I am not aware of any NEC requirement to label or mark a panel that is not supplied with a grounded conductor.

Chris
 
I would either remove the neutral bar or use it as a ground bar (with a bonding jumper of course).
 
I have a UL pamphlet entitled "Marking Guide for Panelboards" which states in part A panelboard designed and intended for use only on a supply circuit involving two different potentials (fro example 120/240 three wire; or 208Y/120 there phase four wire) is so marked
 
I thought it was required by code to state and have a phonic label on all panel(S) stating what's inside!

Maybe I was on a cruise ship!
 
The panel is not a service panel. It is downstream, but that question leads to another aspect of the situation. The panel is fed by an uninterruptible power supply (UPS) system, which has no output transformer and no neutral connection on the output. I could be wrong on this, but I believe that means the UPS would not be considered a separately derived source as defined by NEC Article 100, and since there is no output neutral (grounded conductor), NEC 250.30 cannot apply.
 
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