st colin – Member
An inverter/variable speed drive will work perfectly. Usually for a fan application, step it down a frame size kW wise, as an inverter will ‘boost’ to get a fan going but wont require much to keep it spinning.
Eh?
Surely that will depend on whether the motor is overspec’d for the application or not…
The fan loading on a motor will be proportional to the square of the fan speed, so if the current motor is overspec’d and is essentially running at or near it’s synchronous speed, then underspecing the inverter will be fine.
But, if the motor is the correct size for the application then an underspec’d inverter will will allow the motor to run at slower speeds, however you will then not be able to run at full fan speed if you ever needed to.
Whatever, the inverter needs to be rated for the power required to drive the fan at the maximum speed required…
However, as stated above, does reducing the fan speed still give the required extraction rate for the application?
You might be better off looking for a more efficient fan/motor setup rather than installing an inverter.