jumper
Senior Member
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- 3 Hr 2 Min from Winged Horses
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120/240 3 phase
- Thread starter bobbymari
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bobbymari
Senior Member
- Location
- los angeles ca
should say outside work area not are sorry couldn't rotate, technically outer work area is attached to bldg but as I mentioned earlier it's basically 4x4 posts with a roof
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bobbymari
Senior Member
- Location
- los angeles ca
there we go. technically outer work area is attached to bldg but as I mentioned earlier it's basically 4x4 posts with a roof
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bobbymari
Senior Member
- Location
- los angeles ca
looking at this now I could actually eliminate sub B and wire outer work area from sub A, a little more pipe work as welder plugs are on other side of work area but eliminates breker feeding breaker feeding breaker.... Thoughts???
This is the way that I interpret your application:
You refer to the 240v 3ph as having a neutral, if so I suspect that you actually have a 240/120v 3ph4w system. Often times this system is a delta where (3) 1ph transformers are configured in a delta and one transformer is of a higher KVA with a center tap. It is across that transformer that you would derive your 120/240 1ph3w commonly between the A and C phase, the CT being the neutral. This also can be done with a singe 3ph 240/120 transformer with a 120/240v lighting tap but with significant less KVA available for that tap.
By "stinger to ground" I may guess that you are referring to the 'B' ph to ground voltage hat is actually 208v which is unusable anyway.
You would have 240v between A-B-C and 120/240 1ph3w between the A and C phase with a CT for the N which is then grounded. Please not that a 240/120, 3ph4w transformer will not provide 208v power that can be used. Should you need 208v from 240v a B-B transformer would be required
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bobbymari
Senior Member
- Location
- los angeles ca
templdl: thats the exact setup to the T. As for stinger correct I'm referring to b phase and is not needed. Not sure why they added the transformer for208 as nothing in this complex runs off of 208. Possibly previos tenant equiptment but as of now 3 phase setup which is fairly new is hardly being used other than shop area which is what I want to clean up. the main 3 phase equiptment has its own load center, but they added a transformer converting to 208 after this which I don't need for what needs to be done here.
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Electric-Light
Senior Member
Is there such thing as 7-wire Y setup North America?
Such a transformer N, and A, B,C and A2, B2, C2.
The 2s are taps off each inductor which provides 120v from N to ph while the ends of two branches or neutral to any end provides 240v.
Such a transformer N, and A, B,C and A2, B2, C2.
The 2s are taps off each inductor which provides 120v from N to ph while the ends of two branches or neutral to any end provides 240v.
Hard to say with absolute certainty there isn't... but will say uncommon, if not rare.
kwired
Electron manager
- Location
- NE Nebraska
If you encountered such a thing you about would need to run the 120 portion to one panel, and the 240 (139 to neutral) portion to another panel.
You would have all kinds of possible voltage combinations if you installed a 6 bus panel with neutral ranging from 18, 120, 139, 208, 222, 226, 240
Not what I'm picturing...If you encountered such a thing you about would need to run the 120 portion to one panel, and the 240 (139 to neutral) portion to another panel.
You would have all kinds of possible voltage combinations if you installed a 6 bus panel with neutral ranging from 18, 120, 139, 208, 222, 226, 240
kwired
Electron manager
- Location
- NE Nebraska
Not what I'm picturing...
Not what I am picturing either. I was picturing three phase 240/139 wye system with taps within those windings to be able to achieve 120/208 from the part winding taps. You would have about 19 volts from each tap to the end of each winding. Your picture is(or easily could be) just two wye systems with the neutrals bonded together.
Or three 120/240 systems.
kwired
Electron manager
- Location
- NE Nebraska
How you going to get 208 volts from that?
mivey
Senior Member
Not at a distribution level that I know of. There are some six-phase transmission systems. I think they were mostly a test system but they have been around for a couple of decades so they may be in use more than I think. They were looked at because they could carry more power than a double-circuit 3-phase line. Several other benefits but the phase-shifting may have been a deterrent.
Of course this is common for rectifier inputs where they convert a 3-phase source to a six or twelve phase source. Besoeker has posted diagrams of these.
mivey
Senior Member
The systems would have to be isolated. Once you ground the center-taps of the wye windings, you are back to the six-phase wye that smart pictured.
Leg to same-colored leg (e.g. A to B, B' to C').
Perhaps I should have said "AND" three 120/240 systems
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kwired
Electron manager
- Location
- NE Nebraska
OK I can see that.
Here is what I originally had in my mind:
Voltage from A-B-C is 240 and 139 to N.
Voltage from A1-B1-C1 is 208 and 120 to N.
mivey
Senior Member
Now I see what you meant. Not seen at utility distribution levels. But maybe as part of some auto-transformer setup in the customer premise.
Now that this has been established where do we go from here to keep is simple so to speak? If you have an existing 208Y/120 and you have no use for 208v 1ph or 208v3ph then all that there is left that would be practical is 120v1ph.
It looks as if you have the 240/120v 3ph4w coverered and as such are there any further issues? It looks as if you have a basic application which it appears as if you have under control.
kwired
Electron manager
- Location
- NE Nebraska
I can't say I have ever seen it or what smart$ posted either, but it should be possible.
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