Wye Winding Help

Bwkemmer

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I have a Pearson H milling machine, and it has an Italian motor on it. To my knowledge it has a wye start and a wye run. So I'm kinda at a loss. I have a American Rotary AD 10 phase converter and it says that it will not do wye motors. I called a local motor re-winder, and he told me that it really doesn't matter, hes done many of them and never had issues, I also got the same kind of answer from a fellow at Phase-a-matic. I got a little bit of a different story when i talked to an electrician and he said it would require a transformer to make it work.
This after noon i got a little curious as to if it would work or not when i plugged it in, so i tried, and it worked really well, didnt notice any odd noise, or any smoke coming out of the motor.
So i guess the question is, what are others thoughts on this, and if anyone has had any experience with this kind of thing? Any help is greatly appreciated. Thanks.


There is a pic of the motor tag, and im assuming that the 2 upside down Y's stands for wye run, wye start.


image1.JPG

And a picture of the wiring setup, it is a drum switch on the side of the motor. not sure if it helps much, but the wires are lettered instead of numbered. The top part of the switch is three wires coming in and grounded to the box.
IMG_4689.JPG
 
for all intent and purpose you have 2 choices when running 3 phase, WYE and Delta configurations
most of the 3 phase motors you'll likely come across are wired WYE
in my industry 99% are wired WYE, only a few are delta motors
if it runs and sounds ok, you are fine, make chips!:)
 
This only applies if the center of the Y is required as a neutral, as opposed to floating which is the case with most motors/3 phase machinery. YY configuration is fine, as is the usual configuration for the low voltage configuration of a dual voltage 220/440 or 230/460V motor. I believe this reference in the RPC manual is because the phases are not equally staggered in 120 degree intervals when using an RPC, the third wave is generated between the two legs of single phase. I have yet to see a good explanation and graphical voltage representation of an RPC output voltage, and how this changes with load.

This post explains the issue with the true neutral vs. the generated neutral when using an RPC: http://www.practicalmachinist.com/v...converters-and-vfd/wye-idler-10hp-rpc-305024/
wye-idler-10hp-rpc-rpc_phase-angles.jpg

Per the American Rotary RPC manual.
"The three-phase output is delta configured. Phase to phase voltages are similar to the input voltage, but phase to ground voltages are not all equal. When the two pass through lines measured to ground measure 120v, the third manufactured line will measure approximately 208v to ground. This voltage may vary widely depending upon load conditions. Most machinery requires a delta three phase voltage and this third line voltage to ground should not affect operation. If apiece of equipment requires a wye voltage and requires a neutral connection, the output of the phase converter must be run through a delta-wye transformer to create the neutral. The phase converter must be started before the transformer is connected electrically. This is done with a safety disconnect switch. American Rotary supplies these transformers and disconnect switches."
 
Bwkemmer,
I'm looking forward to meeting you at my shop on Saturday!
Swapping stories and making chips.
Glad you've got some clear responses on your dilemma.

Daryl
MN
 
Thank you Ulma Doctor and mksj. This helped much. Just wanted to be sure I wasn't gonna end up with something bad. And yes uglydog, it should be a good time.
 
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