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Do I have a bad 3-phase motor?

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
Hooked up an old (like WW2) 3-phase motor to a new VFD, and the motor sounded like it was spinning up- actually, it sounded like a small jet engine spooling up- but it was only barely turning. I could stop the pulley with my hand.

I shut it off before the VFD got up to "full speed", pulled the connections and ran an ohmmeter across all four wires- I get roughly 1.5 to 2.2 ohm across pretty much any combination of wires- ground included.

I'm assuming this means there's a short in the fields? Or did I maybe wire it wrong?

Doc.
 
Okay, I'm strongly starting to think the guy that helped me wire this didn't know as much as he thought he did. 'Course, I;m a doofus myself, so what the hey. :D

It's a typical 9-wire, with each wire having a little metal tag, 1 through 9.

They're currently paired 2-8, 3-6, 7-1, and 4-5-6. With the leads from the VFD coming in to the three pairs.

I'm suspecting that's either nowhere near right (online references aren't particularly clear) or it's wired for 440 rather than 220.

If the latter, how would I rearrange this puzzle to go to the lower voltage?

Doc.
 
Okay, I'm strongly starting to think the guy that helped me wire this didn't know as much as he thought he did. 'Course, I;m a doofus myself, so what the hey. :D

It's a typical 9-wire, with each wire having a little metal tag, 1 through 9.

They're currently paired 2-8, 3-6, 7-1, and 4-5-6. With the leads from the VFD coming in to the three pairs.

I'm suspecting that's either nowhere near right (online references aren't particularly clear) or it's wired for 440 rather than 220.

If the latter, how would I rearrange this puzzle to go to the lower voltage?

Doc.

no that's right, except that you have two 6's in there. 3 and 9 should be connected together.

if you had 3 and 6 connected, and 4-5-9 connected, it will not work.
 
Look up 3 phase motor wiring diagrams on google. I think your problem is with 3-6. This should be 3-9 or is the 9 just a misread on your part? Line connection should be to 1,2 and 3.

If in fact the 3-6 connection is correct, then you should have loose 3 lead.

While you are trouble shooting, hang a voltmeter on the leads from the VFD and make sure there is voltage there.

Tom
 
False alarm. It was the VFD. The guy ordered a Huanyang or something off of eBay, and we have no idea what default parameters it has or how to reset it.

But I hooked the motor to the WEG VFD in one of my vertical mills, and she spins right up and quietly hums along at what appears to be full speed.

Anybody got a translated, for-dummies guide on how to set these Huanyang hunks of crap? :D

Doc.
 
Could be your vfd setting was set to ramp up waaaay to slowly.
I've had this problem with a customer in the past running a small super old 2hp motor.
Spun it up but never got full umphdue to its settings.
 
False alarm. It was the VFD. The guy ordered a Huanyang or something off of eBay, and we have no idea what default parameters it has or how to reset it.

But I hooked the motor to the WEG VFD in one of my vertical mills, and she spins right up and quietly hums along at what appears to be full speed.

Anybody got a translated, for-dummies guide on how to set these Huanyang hunks of crap? :D

Doc.
Yes. Easy. Set it in trash.

Sent from my SM-G900V using Tapatalk
 








 
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