Is this a 3PH or 1PH panel? Westinghouse NDP

[ianmurphy]

Hey everyone, this is my first post here so forgive me if this is in the wrong thread or some other violation. I am an electrical designer, not an electrician. Every time I google a question, this forum comes up so I decided to join.

Is this panel 3 phase or single phase? The name plate doesn't say. Its a Westinghouse panel, type NDP. The breakers look like 3 pole breakers to me but I can't under stand the numbering on the panelboard or on the schedule.

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Thanks in advance!

 

[infinity]

Since they appear to all be 3 pole CB's it's a 3Ø panel. The numbers correspond to each circuit breaker if you look closely you can see the numbers, odd on the left , even on the right, adjacent to the CB handle.

 

[Beaches EE]

Even though the _phase and _wire are blank on the nameplate the voltage is 120/208 (should actually say 208Y/120, which is 3 phase.

 

[d0nut]

Even though the _phase and _wire are blank on the nameplate the voltage is 120/208 (should actually say 208Y/120, which is 3 phase.

Just because a 208Y/120V system is 3 phase doesn't mean that every panel connected to it has to be 3 phase. You could just as easily have a 120/208V, single phase, 3 wire panel using two ungrounded conductors and the grounded conductor.

That being said, this particular panel sure looks like a 3 phase panel to me. There is a chance that it is not actually wired as a 3 phase panel, but that would be extremely unlikely given the presence of the 3 pole circuit breakers.

 

[jaggedben]

Even though the _phase and _wire are blank on the nameplate the voltage is 120/208 (should actually say 208Y/120, which is 3 phase.

That's not a clincher by itself. It could be a single-phase panel on a 3-phase service or even a single-phase (or 'network') service that is 3-wire supplied from a 120/208 supply.

But I agree with infinity, a 3-pole breaker is pretty definitive. That would be a real hack job to put that in a single phase panel.

Edit: typing at the same time as d0nut. lol

 

[ianmurphy]

Thanks for the info. I think it was confusing to me because I am used to seeing the poles numbered not the circuit breakers. I checked the downstream panels and they are 3Ø, 4W so it is indeed a 3 phase panel.

 

[jim dungar]

Thanks for the info. I think it was confusing to me because I am used to seeing the poles numbered not the circuit breakers. I checked the downstream panels and they are 3Ø, 4W so it is indeed a 3 phase panel.

Individual pole numbering is pretty standard for the old 'Lighting and Branch Circuit Panelboards'. Numbering of the breakers, regardless of poles, has been the common practice for 'Power Panels' and switchboards almost forever.