1000:1CONSTANT TORQUE

[place1234]

An inverter duty motor normally says "1000:1 constant torque".
what is the "1000:1"? Any standard like NEMA defines that?

Look for your help, thx!

 

[Barry1961]

The 1000:1 is the speed range or turn down ratio. The motor should be able to constantly run at the rated torque at a 1000:1 speed range. For example it could be rated from 2 rpm to 2000 rpm.

There is no standard that I know of for the ratings of “inverter duty” motors. You will have to read the detailed specifications of each motor to get an idea of what they can do. What the motor can do in reality will also depend on the type and brand of VFD. Be sure to check the temperature rise at the speeds you are going to be operating at. Some motors are capable of running hotter than standard wire, THHN, can tolerate.

It would be very difficult to have a standard rating system for “inverter duty” motors unless they were all tested on the same VFD. You might be able to do a standard with a true sine wave VFD but I don’t see it happening.

Barry1961

 

[Skogsgurra]

It is happening. NFO Sinus for instance. Yes, it is a Swedish inverter, but I think that I am allowed to mention that it exists. It outputs pure sine voltage.

Gunnar Englund

http://www.gke.org