How to select a VFD for your motor

Brand Name	GANDO		Place of Origin	China

Delivery Time:2 days
Certification:CE

A variable-frequency drive (VFD) is a system for controlling the rotational speed of an alternating current (AC) electric motor by controlling the frequency of the electrical power supplied to the motor. A variable frequency drive is a specific type of adjustable-speed drive. Variable-frequency drives are also known as adjustable-frequency drives (AFD), variable-speed drives (VSD), AC drives, microdrives or inverter drives. Since the voltage is varied along with frequency, these are sometimes also called VVVF (variable voltage variable frequency) drives.

To?select?a?VFD, ?you?need?to?know?below?data, ?which?you?can?read?on?the?nameplate, ?of?your?motor.

Item	Data
Input?Voltage	___VAC
Capacity	____KW?/___HP
Rated?current	____A
Connection?method	□Delta(△)???□Star(Y)
Motor?pole?Number
Loading
Application?requirement

The VFD specification should meet, at least meet the above data of your motor. Normally we suggest a class bigger.

Please see an example below:

To make sure you select the right model of VFD, we shall pay attention to the loading type and rated current.

Normally we call the water pumps and fans light duty loading, hoisting and crane heavy duty loading, and mostly we call normal duty. the difference between them mainly are light duty loading dose not need large torque from the motor, but heavy loading need large torque at low speed especially the hoisting machine needs large torque all the time.

For?light?duty?loading, ?we?advice?you?choose?P5/V8/M, ?so?the?37kw?380V?inverter?with?model?P5-37T4, ?whose?rated?current?is?75A.?if?your?motor?is?75A, ?a?grade?large?will?better. ? For?heavy?duty?loading, ?we?advice?G7/G11/V5?series, ?the?37kw?inverter?with?G7-37T4, ?whose?rated?current?is?also?75A, ?but?can?output?large?torque?at?low?frequency. ? Normal?duty?you?can?choose?303/V8?series, ?37kw?inverter?303-37T4, ?whose?rated?current?also?be?75Amps.

Commonly we advice one grade larger while choosing the VFD, or at least you make sure the rated current of your motor is smaller than rated current of the VFD.

Please note that the current of your motor is the key point in selecting a VFD.

More question, please contact with our technical and send us the filled data sheet above.. GANDO provides free consultant related to our products.