Originally Posted by
Tycho
I've seen this problem many times, especially on systems where the motor has been sized "perfectly", or with no power to spare compared to the compressor size.
the issue would however be constant.
What is the application? freezing or cooling?
I've had a motor this size stall and cause the VFD to reboot (danfoss) when running on low speed.
We have stopped using the Amps as a safety because they are not "real" amps on the VFD, instead, after consulting with danfoss, we are now using the motor KW as the limiter since this will be a real value no matter what the voltage or amps are changed to to give it the correct HZ.
Another solution is to start with the suction valve closed, but that's not an option when the system is running in auto.
I'm in sydney now, want me to pop over and have a look at it? ;)