Delta to Wye transformer

[dm9289]

In my work area we have incoming transformer with 480-277Y 4000 amp output.
We have many transformers before our motor control cabinets labeled Delta to Wye although our source is Wye, and measures as such.
We had a situation with equipment that we needed a 3 phase 480/277 Y to a 240/120Y.
When the transformer arrived it was marked Delta to Wye so I called the manufacture and they said just hook it up it will work and it did.
I obviously do not understand this help?
Is you using delta/ Wye as Wye/Wye common?

 

[epelectric33]

Delta and Wye are just referring to the transformer windings. It is still the same voltage that you are hooking up on the primary side. There are many instances where I have seen this type of configuration installed to help control harmonics on the system.

 

[MD Automation]

Is you using delta/ Wye as Wye/Wye common?

When you say used as Wye-Wye... Feeding a Delta primary from a Wye source does not change the winding configuration of the primary. Your transformer is still a Delta-Wye.

The Delta wound primary on your transformer input does not care if the supply feeding comes from a Delta or Wye source. All it cares about is getting 3 sets of L-L 480 VAC sine waves (that are 120 degrees apart) to magnetize the 3 primary coils. It does not care what relationship any of those phases has to ground.

You don't feed that primary with a neutral - you just want 3 hots (and a ground). Both a Delta and a Wye supply are going to give you exactly that. From the point of view of your primary coils, both a Delta and Wye supply would look identical.

 

[infinity]

In my work area we have incoming transformer with 480-277Y 4000 amp output.
We have many transformers before our motor control cabinets labeled Delta to Wye although our source is Wye, and measures as such.
We had a situation with equipment that we needed a 3 phase 480/277 Y to a 240/120Y.
When the transformer arrived it was marked Delta to Wye so I called the manufacture and they said just hook it up it will work and it did.
I obviously do not understand this help?
Is you using delta/ Wye as Wye/Wye common?

That is not a wye connected voltage did you mean Delta?

A Delta primary only required the 3 phase conductors so even if the transformer had a Wye primary you would still only use three conductors.

 

[dm9289]

Delta and Wye are just referring to the transformer windings. It is still the same voltage that you are hooking up on the primary side. There are many instances where I have seen this type of configuration installed to help control harmonics on the system.

Thank you would make sense since many are before VFDs

 

[dm9289]

When you say used as Wye-Wye... Feeding a Delta primary from a Wye source does not change the winding configuration of the primary. Your transformer is still a Delta-Wye.

The Delta wound primary on your transformer input does not care if the supply feeding comes from a Delta or Wye source. All it cares about is getting 3 sets of L-L 480 VAC sine waves (that are 120 degrees apart) to magnetize the 3 primary coils. It does not care what relationship any of those phases has to ground.

You don't feed that primary with a neutral - you just want 3 hots (and a ground). Both a Delta and a Wye supply are going to give you exactly that. From the point of view of your primary coils, both a Delta and Wye supply would look identical.

Thank you I think I get it better now. And I have never seen one with any form of use for an input neutral.
I was looking at it as directions. Meaning Delta primary meant connect Delta supply.
Just my misunderstanding of the terminology.