Would like some input, Please?

COMachinist

COMachinist

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Hi All
I’m putting the finishing touches on my House DIY 2x72 grinder, and I seem not be able to find NEMA 56C motor looked at a Baldor VM3558 2hp but it is not rated VFD. So I’m not sure exactly sure what the motor specs should be. I would rather not have to spend $1000.00 on a grinder motor that is only used lightly in the shop. I wont’t be running it 24/7 365 if you know what I mean. The plans don’t spec the motor other than NEMA 56C case mounting for the plate.
any advice is greatly appreciate.
Thank
CH
 
I would not worry about the inverter spec motor for that application since you won't be running real slow or for long times at high torque and low speed. You can set limits to the frequency and my mill and lathe ate set for 30hz-90hz. Never a problem for either old school 3 phase motor.

if I thought i was running it to hard, I would consider mounting a big computer cooling fan on the back of the motor.
 
Motor does not need to be VFD rated to use with a VFD. Most newer motors have higher rated insulation and the problem with insulation breakdown is more of an issue if run on the higher voltages above 400V. Baldor motor will work fine, speed range would be around 20-150 Hz. Baldor VM3558 is a good choice and it is a TEFC.
 
Oh ok, thank you both for the input. I‘ll go ahead and order the VM 3558, should it be run vector or vector less mode, for the grinder?
Thank you again.
CH
 
Sensoless vector mode, need to correct the speed range, too many VFD projects ongoing. Speed range for that motor would be 20-90Hz in sensorless vector mode. Do not need anything fancy control wise, but I would recommend what is called 3 wire control which uses momentary buttons for run (NO switch) and stop (NC switch), you do not need reverse. That way if the power momentary drops it will not restart.
 
Well new plan, I did not get the Baldor motor, so for 2/3 the money of a Baldor and VFDI can get a new in box North America Electric 2hp 56c and a KB AC 27d drive which is simple and will meet my needs for abelt grind in the shop. Any comments of coarse is accepted, thankfully.
CH
 
Baldors are nice, but not a neccesity. I have a 3 phase Dayton on my lathe, which is considered
a less desirable motor, but despite that handicap, it works just fine. You should be good.
 
Well I decided to go with a grinder kit, a new 2 hp North American electric 3600rpm, inverter rated, and a KBAC 27D inverter. The motor has 2 year warrant. So thank for the input, it is appreciate.
CH
 
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