Will running a 1.5hp motor on a 2hp VFD damage it?

Dan Seaver

Dan Seaver

Joined
Jun 25, 2007
Messages
898
I just got off the phone with Kent USA about my surface grinder. The technician couldn't clarify if the motor was 1.5 or 2 hp. I can't either since I can't read Taiwanese. He told me the best thing would be to buy an inverter rated for 2hp since it will run either 1.5 or 2 hp.

He didn't know about VFDs when I talked to him so now I turn to you fellas. Will running a 1.5hp motor on a VFD rated for 2hp damage the motor if I run the motor at the rated RPMs?

Thanks
-Dan
 
I'd quick search for the specs. on the VFD. I know the KBAC-27 that's pretty popular with the 220v 2hp folks, can drive a 110v motor if things are wired right.

Good luck with it, Craig
 
The motor is 220v.

Wait, if i calculate the Kw based on the V and A then I should be able to tell if the 1.5 is for the HP or Kw. Thus letting me know if its 1.5 or 2hp.
 
Amperage is the key. You can always run less amperage than the unit is rated for. I would think you would be OK. One can usually run a smaller motor than what the VFD is rated for. But, you must be sure that the motor on the unit is 3 phase, as the VFD will convert the 220v single phase to 220v 3 phase. I am assuming you do not have 3 phase service in your shop- only 220v single phase.

Milt
 
Nothing bad will happen from using a VFD rated for 2HP. Actually that is safer since the 1.5hp motor will not be working over the VFD as hard as the 2hp motor. I run a 2HP motor on a 3HP rated VFD so I know that --hopefully-- the VFD will never pop from getting worked over.
 
No problem with a smaller 3 phase motor on a bigger inverter (VFD). The motor draws the amps, the inverter doesn't shove 'em in. If your motor draws more than the VFD can provide, it will click off to protect itself.
It's like you have 100 amps going into your home service with 20 amp breakers, but your toaster only draws .5 amps. 20 amps are available, but the toaster only draws .5.
 
Excellent. Thanks for the help guys. The motor is only .97Kw so its 1.5hp but I'll still get a 2HP vfd just to be safe. :thumbup:

VFD- $240
Magnetic chuck- $400
Grinder- $550

$9000 surface grinder for $1200- priceless :D hehehe
 
It is a 3 phase 208V motor right? Trying to run a single phase motor on a 3 phase VFD, well you couldn't even wire it up properly.
 
Edit. I think I found a capacitor in the electrical control box. :confused: It says 1 P.H. on it too. But it doesn't look like any capacitors I have ever seen. I'm gonna have my buddy take a look at it tonight and I'll post a picture later.
 
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