What's new
What's new

VFD reccomendation 15 hp motor


Cast Iron
Feb 16, 2004
Kiron IA USA
I have a machine that has been operating with a 10 hp and 5 hp single phase motors belted to it. It has worked OK for years. I am having trouble with the 10 hp motor tripping thermal switch. I have been watching amp draw and it is not overloaded. I wonder if thermal overload switch is weak? I may try a remote overload switch as the motor is 90 feet in the air. Not easy to use IR heat gun to see what temperature is. If the different overload devices don;t solve problem, I will replace with a new 15 hp motor and VFD. What VFD should I look at? I have used VFDs for 25 years but 1 hp is a different commitment than a 30 hp model.The machine can not be used at any speed but motor rated so variable speed is not any value. Maybe just put together a 30 hp idler phase converter?

Look at this.
Last edited:
If the location the motor is in happens to be dusty, the motor may just be choked with dust, Either inside if it is open, or if it is a closed motor, the fins may be thickly coated with dust, etc.