oscar47
Member
- Location
- Destin, fl
Is it possible to connect 208Y as the primary and get 480 as the secoundary on a 480 Primary to
208Y secoundary transformer?
208Y secoundary transformer?
480/208Y Transformer
- Thread starter oscar47
- Start date
- Status
Yes but, you wouldn't connect it as wye/delta, you would connect it as delta/delta.
Roger
- Location
- New Jersey
- Occupation
- Journeyman Electrician
You would need to have a 208 volt input which would still be WYE connected just without a neutral.
Rob, you would in fact have a wye voltage but, you would connect it delta/delta or as you put it, without the neutral. With that being said, now one of the out put phases need to be grounded or install a ground detector.
Roger
ceb58
Senior Member
- Location
- Raeford, NC
Hi Roger. I will throw this in. The 480p/208s ones I have reversed like this, I made sure that they were marked "Suitable for reverse connection" Just in case we got an inspector who was looking for something to do.
Hey Curtis, you have a good point as far as some of our inspectors are concerned. BTW, the boat's ready and I'll buy the bait this time.
Roger
ceb58
Senior Member
- Location
- Raeford, NC
I will buy the bait if you don't forget the tackle boxHey Curtis, you have a good point as far as some of our inspectors are concerned. BTW, the boat's ready and I'll buy the bait this time.
Roger
texie
Senior Member
- Location
- Fort Collins, Colorado
- Occupation
- Electrician, Contractor, Inspector
As others have indicated, yes you can. Is it good idea? IMO, no for most applications. One problem, among others, with this is the now 480 output is delta, which leaves you with no neutral for easy grounding of the SDS. And what if you need a neutral anyway? Of course it can be corner grounded or possibly even ungrounded, but that brings on other requirements/issues.
A 208 delta to 480 wye is not that hard to get-just not as common as the other way.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I'm not understanding how if you have a 480-208/120 volt transformer wired in reverse how you would physically make the 208 volt connection a Delta? Isn't it factory connected in a WYE configuration with one side of each winding connected to the X0?
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
If you only connect the load or supply to the three phase wires, the load/supply cannot tell the difference between wye and delta, but the current in the transformer windings will be different depending on whether that side is delta or wye internally. The current in the phase wires on that side will be the same at any given power level, but the current in the windings that results will be different.
brian john
Senior Member
- Location
- Leesburg, VA
The primary (208 VAC) side is still a wye, X1, X2, X3 are all connected at X0 and the ratio is 1 to 4 or you might argue 2.3 to 4.
Last edited:
mike_kilroy
Senior Member
- Location
- United States
You are correct.
It is still Y input using X1,X2,X3 and not hooking up X0.
If one WERE to change it to a delta they would then have not a 208vac 3ph input but a 360v in to 480v out xfmr; or putting 208 into the reconfigured delta's old 208 input, they would only get 277v L-L out the new secondary.
Rob, you are missing my point. I am not insinuating there is a change in the windings, all I am saying is, for simplicity purposes, the actual connections to the transformer will be the same as delta/delta as in X1, X2, X3 / H1, H2, H3, there is no XO or HO in the picture.
You are absolutely correct that we are still connecting a wye to a delta.
Roger
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