- #1
SevenToFive
- 56
- 3
How does one calculate the amount of HP a motor makes when it is not running at a full 60Hz?
The reason for my asking is a customer wants to use a 1/4HP motor and a gearbox to vary the speed of a conveyor. At a full 60Hz we are figuring 1750rpm for the motor, and through the 7:1 gearbox the output speed would be 250rpm, but they also want to slow it down to 3.3rpm. This can be done using a VFD and having the motor output speed at 27.25rpm. However most gearboxes are rated for HP, so as speed goes down torque goes up and we do not want to exceed the torque rating by exceeding the tooth strength of the gearbox. Other applications will be using a 1/2HP motor, 1HP, and 2HP motor with larger gearboxes but in the same speed ranges.
Is there a way to calculate the motor HP when the frequency and speed decrease?
Thanks to all of hose who reply.
The reason for my asking is a customer wants to use a 1/4HP motor and a gearbox to vary the speed of a conveyor. At a full 60Hz we are figuring 1750rpm for the motor, and through the 7:1 gearbox the output speed would be 250rpm, but they also want to slow it down to 3.3rpm. This can be done using a VFD and having the motor output speed at 27.25rpm. However most gearboxes are rated for HP, so as speed goes down torque goes up and we do not want to exceed the torque rating by exceeding the tooth strength of the gearbox. Other applications will be using a 1/2HP motor, 1HP, and 2HP motor with larger gearboxes but in the same speed ranges.
Is there a way to calculate the motor HP when the frequency and speed decrease?
Thanks to all of hose who reply.