Can this motor be wired for 240v?

Ropata

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Hi guy's,

As per the title, is there an easy way to tell if this WEG branded motor can be wired for 240 volt? I have an old VFD that outputs 240 3 phase only.

20171005_184622.jpg 20171005_184635.jpg 20171005_184756.jpg
 
Should be able to. It appears to be 400V star connected so if you reconfigure it as a delta motor it would need 240V. Would pull a bit extra current if fully loaded but that should be OK.

All six winding ends seem to be taken out to the terminal box (looks like the top two rows in the photo) so you would just remove the shorting bar from the top three and then reconnect something like this

upload_2017-10-5_8-56-40.png


That is assuming each winding is connected to terminals that are in line. You would need to do a continuity check as they sometime do the step internally so that the delta links are just vertical (ie one winding will internally connect to say the top right terminal and the bottom middle)
 
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Thanks Peter. Can any damage be done if I do it wrong first time or will the motor just spin the wrong way?
 
You say your VFD outputs 240V 3 phase. Just check that that is 240V between two phase, not phase to earth. Equipment running on 240V between phases would be unusual in NZ, the normal household supply is 230V phase to earth so already 380V phase to phase.

You may not need to reconfigure the motor.
 
Sorry Peter, this is all Greek to me. I might take a better look at both the motor and the VFD in the morning and report back. We run on 240v single phase multiple earth neutral. I think our system is identical to China.

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I'm actually a kiwi - just live/work in Africa. That's why I started to think a 240V 3 phase VSD would be a strange thing to have there.
 
Wonder what the bottom row terminals are for?
Mark S.
 
Motors with terminals like that usually are connected in straight lines so you can just re-position the links.
 
Should be able to. It appears to be 400V star connected so if you reconfigure it as a delta motor it would need 240V. Would pull a bit extra current if fully loaded but that should be OK.

All six winding ends seem to be taken out to the terminal box (looks like the top two rows in the photo) so you would just remove the shorting bar from the top three and then reconnect something like this

View attachment 243427


That is assuming each winding is connected to terminals that are in line. You would need to do a continuity check as they sometime do the step internally so that the delta links are just vertical (ie one winding will internally connect to say the top right terminal and the bottom middle)


Even easier than that, most 3-phase dual voltage motors are set up with the winding ends already staggered, so three short, straight links and you have delta... With the links off, there will be open circuit from one to the other "vertically" and as Pete says, from one of each vertical pair to the opposite of the next pair.

The pair at the bottom of the pic may be for a thermal switch, to disconnect (via a contactor) if the motor overheats, or even a magnetically operated brake (hard to tell without a pic of the other end of the motor).

Dave H. (the other one)
 
Even easier than that, most 3-phase dual voltage motors are set up with the winding ends already staggered, so three short, straight links and you have delta... With the links off, there will be open circuit from one to the other "vertically" and as Pete says, from one of each vertical pair to the opposite of the next pair.

The pair at the bottom of the pic may be for a thermal switch, to disconnect (via a contactor) if the motor overheats, or even a magnetically operated brake (hard to tell without a pic of the other end of the motor).

Dave H. (the other one)
Great. I'll do a video after work of a continuity check of all connections. Should I pull off the short bars so all terminals are isolated first? the motor is off an old wood working machine, maybe a thicknesser.
 
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