andykee
Member
- Location
- United States
If I have a 3 phase combiner panel with 240v on a single phase(435v ph-ph), can I feed each hot pin of a nema6 15 outlet from the same phase to get 240v?
Wiring 240v receptacles with a single 240v phase?
- Thread starter andykee
- Start date
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- Location
- Massachusetts
Two conductors from the same phase gives you 0 volts.
andykee
Member
- Location
- United States
That was what I thought, so is a small step-down transformer the best solution?
- Location
- Massachusetts
I do not know what you are trying to accomplish.
Can you tell us more about this combiner panel? Is it part of a solar module array?
K8MHZ
Senior Member
- Occupation
- Electrician
How many conductors are there on a single phase?
He said he got 435 volts on a single phase. I took it that he was asking if putting a 240 volt receptacle on that phase was acceptable.
It looks like you took it as each conductor was a 'phase' and two parallel conductors were going to be run to the receptacle from a single conductor, which would indeed give 0 volts from conductor to conductor.
I think we may need some clarification from the OP, but I think the jist of it is that he can't get 240 volts without a transformer.
- Location
- Massachusetts
andykee
Member
- Location
- United States
K8MHZ
Senior Member
- Occupation
- Electrician
Not so much as you think. What is the definition of a phase? To me, a phase IS two conductors. To others, it is a single conductor.
To me, the following would put 435 volts on the receptacle, as I consider a phase to be two conductors.
No matter, I think we agree that it won't work the way he wants it. If he thinks a phase is a single conductor, he will get 0. If he thinks a phase is two conductors, he would get 435.
If there was a neutral, he could get 250 volts from 435. That's pretty close to 240.
K8MHZ
Senior Member
- Occupation
- Electrician
So somewhere there is a Y transformer with 244 volts L-N, correct?
- Location
- Massachusetts
The screenshot indicates it is a wye so there is a neutral, you would use one ungrounded phase and the grounded conductor/ neutral to get 244 volts to the receptacle.
- Location
- Massachusetts
Yet the OP sees it like I do so ...
andykee
Member
- Location
- United States
So if the system is 422Y/244 V can I wire that outlet as L1 and Neutral on each of the receptacle horizontal pins?
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
It depends on whether the receptacle is rated for 240 to ground or only 120 to ground. Same issue as slash rated breakers.
- Location
- Massachusetts
The only issue I see with that is a NEMA 6 outlet is marked for two ungrounded conductors and you will have an ungrounded and a grounded conductor.
It will work but I am not sure if it is a listing violation.
K8MHZ
Senior Member
- Occupation
- Electrician
That was my concern, too. Using, instead, Nema 7-15 for 277 volts would only have one hot, as it would be one leg of a 480 volt three phase to neutral, meaning only one ungrounded connector.
But then, it's a 277 volt design fed with 240-250 volts.
- Location
- Massachusetts
That was my concern, too. Using, instead, Nema 7-15 for 277 volts would only have one hot, as it would be one leg of a 480 volt three phase to neutral, meaning only one ungrounded connector.
But then, it's a 277 volt design fed with 240-250 volts.
Nice find, I might be more inclined to use that one.
mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
If the panel has neutral L-N and call it a day. Make sure your breaker can handle 240 volts to ground, In North America this usually dictates a 277/480 volt rated panel.
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