120/240 v single phase panel

[jap]

As stated in post #3, it is a 120/208Y volt panel fed from a 208Y/120 volt system; per IEEE C84.1 Table 1 Note (d).

It would not be a Y system to a single phase sub panel.

You cant have a Y if you don't have all 3 legs.


JAP>

 

[jap]

Maybe it should be called a V system to the subpanel.


JAP>

 

[kingpb]

Maybe it should be called a V system to the subpanel.


JAP>

You can argue or disagree all you'd like, it will not change what the standard says.

Perhaps you should contact IEEE standards committee and formulate your argument with them.

Cheers~

 

[jap]

You can argue or disagree all you'd like, it will not change what the standard says.

Perhaps you should contact IEEE standards committee and formulate your argument with them.

Cheers~

Nah,,


JAP>

 

[jap]

No need to confuse or convolute a simple issue.

JAP>

 

[Besoeker]

No need to confuse or convolute a simple issue.

JAP>

Seems to be par for the course here..............

 

[jap]

Seems to be par for the course here..............

It is, but even after all the back and forth, we try not to get too serious about it.


JAP>

 

[petersonra]

I am certainly confused.

 

[Besoeker]

Maybe it should be called a V system to the subpanel.
JAP>

That would make some sense.

 

[kwired]

So what do you properly call voltages that feed 120/208v 1ph panels that are fed from a 120/208v Y 3ph panel?


JAP>

If labeled or plans are marked "120/208 single phase" - I will take that to mean two phase conductors and the neutral of a wye system. Only "usual" way to have both those voltages between just three conductors is via a wye connected source, or an inverter that is simulating wye output.

 

[jap]

If labeled or plans are marked "120/208 single phase" - I will take that to mean two phase conductors and the neutral of a wye system. Only "usual" way to have both those voltages between just three conductors is via a wye connected source, or an inverter that is simulating wye output.

I completely agree, but, as indicated in post #40, it's magically a 120/208Y volt subpanel fed from a 208Y/120 volt system; per IEEE C84.1 Table 1 Note (d).

I'm still trying to figure out how you can feed a subpanel single phase 120/208 volt from a 208Y/120 volt system and it still be considered a Y at the subpanel with only 2 phase conductors and 1 neutral.

I'm being sarcastic of course.


JAP>

 

[Besoeker]

If labeled or plans are marked "120/208 single phase" - I will take that to mean two phase conductors and the neutral of a wye system.

And that's the crux....not one but two.
No matter what you call it.
L1 to N is not in phase with L2 to N.
How can that really be single phase no matter what you call it?

 

[petersonra]

I completely agree, but, as indicated in post #40, it's magically a 120/208Y volt subpanel fed from a 208Y/120 volt system; per IEEE C84.1 Table 1 Note (d).

I'm still trying to figure out how you can feed a subpanel single phase 120/208 volt from a 208Y/120 volt system and it still be considered a Y at the subpanel with only 2 phase conductors and 1 neutral.

I'm being sarcastic of course.


JAP>

It is still a Y system at the source. I don't see how it is still not part of that service or system just becasue you did not run all 4 wires.

 

[kwired]

I completely agree, but, as indicated in post #40, it's magically a 120/208Y volt subpanel fed from a 208Y/120 volt system; per IEEE C84.1 Table 1 Note (d).

I'm still trying to figure out how you can feed a subpanel single phase 120/208 volt from a 208Y/120 volt system and it still be considered a Y at the subpanel with only 2 phase conductors and 1 neutral.

I'm being sarcastic of course.


JAP>

FWIW you still can derive three phase from it with an open delta primary connected transformer.

Oops,said that wrong - open delta secondary

 

[jap]

It is still a Y system at the source. I don't see how it is still not part of that service or system just becasue you did not run all 4 wires.

Sure it's a part of it. That's a no brainer.

But we're not talking about the source we're talking about a branch off of that source.


JAP>

 

[jap]

FWIW you still can derive three phase from it with an open delta primary connected transformer.

Oops,said that wrong - open delta secondary

Leave the transformer out of it.

There is not 3 phases at the subpanel.

JAP>

 

[Besoeker]

Leave the transformer out of it.

There is not 3 phases at the subpanel.

JAP>

Correct. Just two.

 

[kwired]

Leave the transformer out of it.

There is not 3 phases at the subpanel.

JAP>

I never said there was, I said you can derive three phase from this panel. Can't do that from same panel if it is supplied by 120/240 three wire supply. More common to see it done from medium voltage distribution lines, but concepts are still the same.

Have a commercial space with 120/208 three wire feed to it and need a three phase circuit - is one possible way to do it.

 

[LarryFine]

And that's the crux....not one but two.
No matter what you call it.
L1 to N is not in phase with L2 to N.
How can that really be single phase no matter what you call it?

Because L1-N is single phase, L2-N is single phase, and L1-L2 is single phase.

 

[kwired]

And that's the crux....not one but two.
No matter what you call it.
L1 to N is not in phase with L2 to N.
How can that really be single phase no matter what you call it?

You can not directly run a three phase load from it, though as I earlier mentioned you can derive an open delta system from it from which you can directly run a three phase load.

You might be able to connect a three phase motor to both lines and to the neutral and it might run, but you have horrible voltage balance and it probably destroys that motor in no time, unless you do some transformation before connecting to the three phase motor.