Service Wye:g wiring a Step Down Tx Wye-Wy:g

[ChrisCentral]

Good Afternoon,

I'm a new grad and my 4th yr professor told us never wire the HV neutral of a Wye-Wye:g step down Tx into a Wye:g service. Something about Neutral currents but I can't recall? I'm working on a design and the electrician wants to use a Wye-Wye:g TX on a 4-wire Wye:g service.

I know the secondary of the step down can have a neutral and it must be grounded but..

Why should I not land a neutral on the primary of the step down Wye-Wye:g Tx?

Thanks!!

 

[WesR]

Problems could occur if harmonics are present, among other things. I found this paper to be insightful:

http://www.geindustrial.com/publibrary/checkout/GET-3388B?TNR=White%20Papers|GET-3388B|generic

 

[ChrisCentral]

Thanks WesR