Testing 3 phase motors

I am testing a couple of 3 phase motors I have acquired. I have a single phase to 3 phase 3/4 hp rotary converter that generates the 3 phase field. I have checked a couple motors but when I tested 2 Baldor motors I tripped my fused switches. The first heated my switch red hot and the second turned slowly then killed my FRS 5 fuses in my converter set up. Both were 2-3 hp but I checked a different manufacturer 3 hp motor and it ran fine. So at this point I need to get more fuses. I had the motors wired for low voltage to match my 240 supply. I checked these wiring configurations thoroughly.

How do I test these 3 phase motors? I checked resistance between a 3 leads and measured a couple of ohms each. No spikes.

Also, I am looking to use these 3 phase motors for an idler in a separate rotary phase converter. I have read about getting a balanced voltage. Would this be just measuring the 3 voltages from the 3 different combinations of leads? What is a decent balanced voltage supply - say for mills or lathes?

Thanks Pal

Reply to
Pal
Loading thread data ...

Pal

You seem to be doing the testing of the 2 or 3 HP 3 phase motors properly. If the motor is possibly faulty, maybe you can evaluate it by connecting a

12 VDC battery to any two of the leads to the 3 phase motor and test the resistance to 'twisting the rotor shaft'.

If you want any additional assistance with your testing you are welcome to E-mail me at home.

Jerry

Reply to
Jerry Martes

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.