Selection of ID Fan Motor

Calling them, maybe:

GE brings good things to life!(tm)

can't wait for the entertainment and your answer that is usable

kW
voltage
frame number
enclosure rating
any special features required

and possibly more

further inputs.... attending class!!

Sir,

As others have implied, your post leaves more than one piece of information missing--such as desired air flow, efficiency of the fan, and others. This is a very large fan, and will require a very significant amount of time to get up to its operating speed. Although the torque requirement will be important for motor sizing, you don't mention anything about starting method....

--JMM

The motor is basically an electromechanical device which draws power from the network and converts electrical energy into mechanical power by developing torque at motor shaft which is transmitted to the driven equipment through coupling. Hence the selection of motor can't be viewed in isolation.

The major parameters which are associated with selection of motor are as under:

i) Starting torque or locked rotor torque: the torque developed by the motor at standstill (s=1)

ii) Rated torque: the torque developed by the motor at rated speed with rated voltage and frequency available at motor terminal

iii) Pull up torque: minimum torque developed by the motor during the process of acceleration

iv) Pull out torque or breakdown torque: maximum torque developed by the motor with rated voltage and frequency available at motor terminal

v) Speed torque characteristics of the motor based on the above four parameters

vi) Starting duty: No. of allowable cold and hot starts per hour

vii) Hot and cold thermal withstand curve of the motor.

viii) Load inertia (GD² value) with respect to motor shaft

ix) Load curve or speed torque characteristics of the driven equipment

Item no. i) to vii) are inherently motor parameters which should be taken into consideration while designing the motor to drive a load with characteristics defined by item viii) and ix).

Unless the mechanical load has a very high inertia with a typical speed torque characteristic (say ball mill, crusher, and centrifugal blower) normally standard motors (NEMA design A or B) should suffice. But these parameters should be checked before putting the motor into service. Proper setting of the overload relay of the DOL starter should also be looked into considering the starting time, starting duty and thermal withstand curve of the motor.