Auto Tx - Neutral Currents???

[ChrisCentral]

Good Afternoon,

I need to install an Auto Tx to step up the voltage of a 480VAC 3-ph 50kW generator to the connection voltage of the building 600VAC (Canada).

I am worried about neutral currents (The Wye's of Wye's) but Auto Tx's are a different beast!

The service Tx to the building is 347/600VAC Wye:g... should I connect the Neutral or not? What about the fact that the XO and HO are the same in an Auto Tx?

I think no Neutral connection and no ground connection on the XO/HO point but any advice or tips otherwise would be very helpful.

Thanks!!

 

[chris kennedy]

That doesn't sound like an auto tranny, how many kva you talkin?

 

[templdl]

It would help a lot if the OP would post a one line diagram For what he's describing.

 

[GoldDigger]

Good Afternoon,

I need to install an Auto Tx to step up the voltage of a 480VAC 3-ph 50kW generator to the connection voltage of the building 600VAC (Canada).

I am worried about neutral currents (The Wye's of Wye's) but Auto Tx's are a different beast!

The service Tx to the building is 347/600VAC Wye:g... should I connect the Neutral or not? What about the fact that the XO and HO are the same in an Auto Tx?

I think no Neutral connection and no ground connection on the XO/HO point but any advice or tips otherwise would be very helpful.

Thanks!!

I assume that the building has some line to neutral loads.
If it does, you must supply a grounded H0. Normally you would do that via a delta to wye transformer even with a wye service. But with each of your windings being an autotransformer (boost), you cannot avoid grounding the XO too.
I don't think you can do what you want.
I also do not see a delta to delta setup you can do without isolation, unless you have a corner ground service.

 

[templdl]

It would really be a great help of the OP included a one line diagram on his application. If so his question probably could be answered easily.

 

[kingpb]

Good Afternoon,

I need to install an Auto Tx to step up the voltage of a 480VAC 3-ph 50kW generator to the connection voltage of the building 600VAC (Canada).
Thanks!!

Your voltage is 480V 3ph. If stated correctly, there is no neutral. Utilizing a transformer to step it up would simply be a delta LV side with wye grounded HV side (480-600V). The generator will be grounded at the generator.

If the service is 600Y/347V then you can take the neutral off the HV side of the step-up transformer to the service.