What's new
What's new

Transformer in reverse/delta vs wye?

Greg Quenneville

Hot Rolled
Joined
May 26, 2005
Location
Gold Coast,Queensland Australia
I need a small step-up 3 phase transformer 240-415v. I have found a 4.8 kva step-down transformer that I plan on running in reverse. The data plate says:

1RY: 415/400/380/360 V Wye 50/60 Hz
2RY: 200v 14A Delta

What is the significance of the Wye and delta in the windings? I am planning on running my 230v three phase into the 200v side for an approximate 430v output from the 360 terminals.

Can an expert please advise if I am on the right track with this plan?

(load motor is a two-speed reversible 380-440v YY/delta wound, 1.6Amp. Rewinding shop quoted $500 to convert to 240v three phase)

Thanks for any and all help on this one.

Greg
 
Keeping it simple the wye and delta are just ways to describe how the windings are connected to the wiring / each other. Many times Delta is used in a higher current demand situation, allowing very balanced loading, but when a grounded leg / common is not needed. The wye can use a common leg / neutral via a balanced shared center tap. I'm in no condition to expound on this stuff tonight, but I'd say you are on the right track. Just make sure your over-current protection is adequate. A good safety measure it to double check your xfmr connections when done, turn it on w/ no load and then check your output voltages.
Transformers tend to let their smoke out less like a smoke bomb, and more like a stick of dynamite.

Good Luck,
Doug S.
 
"1RY: 415/400/380/360 V Wye 50/60 Hz

"2RY: 200v 14A Delta"

Most likely, this was a specialty transformer intended on supplying Japanese utilization equipment (most is 200) from European power sources (380/400/415).

Use it in reverse to step-up your local power (probably 230) to "400 class".

Protect the transformer with a 15 amp C.B. (the next size to 14 amps), or possibly 20 amps.
 
Thanks guys, that confirmation is what I needed. I will connect it with a three phase breaker in the line from the RPC. I'll have to fab up an enclosure for it too.

Peter your mentioning Japanese equipment makes sense...I know their single phase stuff is 100v, and this unit is in fact Japanese made.

Greg
 








 
Back
Top