480v high leg motor issue

[ptonsparky]

[soapbox] Fair enough. [/soapbox]

 

[winnie]

So is there such thing as a 480v delta high leg? If so, what would be your voltages?

It is certainly possible to have 480V delta high leg.

You would need a transformer that provides a 480V delta, and one of the 480V coils would have a mid point tap. The midpoint tap would get grounded. If you set this transformer up this way, you would have 480V L-L for all 3 phases, and L-G voltages of 240V, 240V, and 416V.

There is a good diagram midway down this page: https://ctlsys.com/support/four_wire_delta_circuits/

 

[MD Automation]

Nobody could ever tell me what they were, thank you

You are most welcome.

Here is a very typical nameplate from a common Delta -> Wye step down transformer, you can see the 2 dashed lines on the primary and secondary showing a 30 degree phase shift between them. The dotted line on the Delta Primary is "angled" up 30 degrees and the dotted line of the Wye Secondary (at X0) is straight across with zero "angle"



Your Delta to Delta coil setups are straightforward and as the current rises in any one primary coil, it does so at the same time in its secondary mate. So zero phase shift and the dotted lines in your nameplate at H1 and X1 show the same angle - with no shift between them.

This phase shift is mostly a nerdy thing and it is very common for them to get misinterpreted as some kind of grounding indications. But they are not, it's science yo !

Also, sorry this thread is sliding off the rails into the transformer weeds - I assume your motor problem is not related to your transformer.

Again - good luck!

 

[journeyman0217]

You are most welcome.

Here is a very typical nameplate from a common Delta -> Wye step down transformer, you can see the 2 dashed lines on the primary and secondary showing a 30 degree phase shift between them. The dotted line on the Delta Primary is "angled" up 30 degrees and the dotted line of the Wye Secondary (at X0) is straight across with zero "angle"

View attachment 2579091

Your Delta to Delta coil setups are straightforward and as the current rises in any one primary coil, it does so at the same time in its secondary mate. So zero phase shift and the dotted lines in your nameplate at H1 and X1 show the same angle - with no shift between them.

This phase shift is mostly a nerdy thing and it is very common for them to get misinterpreted as some kind of grounding indications. But they are not, it's science yo !

Also, sorry this thread is sliding off the rails into the transformer weeds - I assume your motor problem is not related to your transformer.

Again - good luck!

This is awesome…completely makes sense to me now. Thank you for taking the time to explain. Definitely didn’t derail because I’m understanding now what the overall scenario I have going on is. Just an update it seems as if the control coil to the contact is bad and not providing the necessary voltage to fully engage the contact, therefore closing our “low voltage” relay.