How to size a speed pot for a VFD?

My basic DC-101 Electronics is failing me today.

First off, I already have a call into the manuf's tech support about this, but how would you go about determining the resistance required for a speed pot for a 0-10VDC signal feed into a VFD.

What info needs to be known about the drive board's spec's?

Consult the manual for the drive. That should include the manufacturer's recommendation for the size of an external speed pot. Typically 5K or 10K.

The thing you have to remember about a potentiometer vs. a rheostat is that the "pot" is used to provide a differential voltage between the two legs and the center, moving, tap. It is the ratio between the resistances on each side of the center tap that matters, and as long as the resistance is high enough to prevent excess current the value isn't usually critical. As Steve points out, the manufacturer will provide the allowable range in his manuals.

Thanks for your help guys.
I finally found the proper manual for the VFD. Was having trouble even finding that.

Looks like 10K is it.

dogleg43 said:

Thanks for your help guys.
I finally found the proper manual for the VFD. Was having trouble even finding that.

Looks like 10K is it.

Click to expand...

When purchasing, make sure you order a 10K linear potentiometer, not a logarithmic one.