Phase Converter Buzzing

Grenade said:

I've just finished putting together a 10HP phase converter using an American Rotary panel and a self supplied idler motor. The idler motor is making a buzzing noise when there's no load on the circuit. As soon as I apply a load it goes away. See the video in the link below.

VID_20200601_113019_LS.mp4 - Google Drive

American Rotary support was great until they realized I was using my own idler motor, then they told me to buzz off (ha). Below are the voltage readings between legs.

Loaded__________Unloaded
L1-L2: 238_______L1-L2: 239
L1-L3: 233_______L1-L3: 250
L2-L3: 230_______L2-L3: 232


Does anyone have any idea what's causing this and how I can resolve it? Thanks in advance!

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johansen said:

remove some of the run capacitors until you see that 250 volt number drop a bit, or just ignore it. 250 volts no load is not too high.

you can then take those capacitors which were removed and move them to the load so they are only switched in when the load is turned on.

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johansen said:

remove some of the run capacitors until you see that 250 volt number drop a bit, or just ignore it. 250 volts no load is not too high.

you can then take those capacitors which were removed and move them to the load so they are only switched in when the load is turned on.[/QUOT

Interesting !! Caps in the load. All three phases?? Or just generated phase?

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