Three phase delta- wye transformer connection

[gpang]

According to my "GE Distribution Transformer Manual", a delta-wye transformer with a 30 degree angular displacement (additive polarity) has a primary phase connection of H1A to phase A, H1B to phase C, and H1C to phase B. My question is, why is the phasing connected in this sequence and not ABC? Does the sequence of phase connection matter?

Thanks

 

[david luchini]

According to my "GE Distribution Transformer Manual", a delta-wye transformer with a 30 degree angular displacement (additive polarity) has a primary phase connection of H1A to phase A, H1B to phase C, and H1C to phase B. My question is, why is the phasing connected in this sequence and not ABC? Does the sequence of phase connection matter?

Thanks

I'm at a loss to understand what they are trying to tell you. H1A, H1B and H1C don't seem to be common terms for transformers.

I would expect to see a D-Y transformer connected H1, H2, H3 as ABC to correspond with X1, X2, X3 as ABC on the secondary side.

Maybe you could post a bit more from the Manual to clarify.

 

[gpang]

I'm at a loss to understand what they are trying to tell you. H1A, H1B and H1C don't seem to be common terms for transformers.

I would expect to see a D-Y transformer connected H1, H2, H3 as ABC to correspond with X1, X2, X3 as ABC on the secondary side.

Maybe you could post a bit more from the Manual to clarify.

Sorry, but what I was trying to say was, GE shows the connection of H1 of transformer A and H2 of transformer C is connected to the incoming/primary phase A; H1 of transformer B and H2 of transformer A is connected to the incoming/primary phase C; and H1 of transformer C and H2 of transformer A is connected to the incoming/primary phase B. This is in regards to the three points of the delta connection on the primary. The secondary phasing follows the same phasing as the primary, A,C,B. I hope this helps.

 

[david luchini]

Sorry, but what I was trying to say was, GE shows the connection of H1 of transformer A and H2 of transformer C is connected to the incoming/primary phase A; H1 of transformer B and H2 of transformer A is connected to the incoming/primary phase C; and H1 of transformer C and H2 of transformer B is connected to the incoming/primary phase B. This is in regards to the three points of the delta connection on the primary. The secondary phasing follows the same phasing as the primary, A,C,B. I hope this helps.

Assuming you meant B in red above, yes, that connection would give you a standard 30deg lagging phase shift.

You could achieve the same 30deg lagging phase shift with an A,B,C connection (rather than an A,C,B connection) by connecting the transformer like this...

H1 of transformer A and H2 of transformer B is connected to the incoming/primary phase A;
H1 of transformer B and H2 of transformer C is connected to the incoming/primary phase B;
H1 of transformer C and H2 of transformer A is connected to the incoming/primary phase C.

 

[gpang]

Assuming you meant B in red above, yes, that connection would give you a standard 30deg lagging phase shift.

You could achieve the same 30deg lagging phase shift with an A,B,C connection (rather than an A,C,B connection) by connecting the transformer like this...

H1 of transformer A and H2 of transformer B is connected to the incoming/primary phase A;
H1 of transformer B and H2 of transformer C is connected to the incoming/primary phase B;
H1 of transformer C and H2 of transformer A is connected to the incoming/primary phase C.

THANKS for the explanation, it was very helpful.

 

[arrehman1]

video tutorials

video tutorials

According to my "GE Distribution Transformer Manual", a delta-wye transformer with a 30 degree angular displacement (additive polarity) has a primary phase connection of H1A to phase A, H1B to phase C, and H1C to phase B. My question is, why is the phasing connected in this sequence and not ABC? Does the sequence of phase connection matter?

Thanks

This youtube video tutorial for delta wye transformer connection might help - http://gpac.link/1IKAS52
Also this one with CTs connected in DAB connection - http://gpac.link/1EtRiBa