# How to determine the motor power of the fan The selected motor power N=(Q/3600)*P/(1000*η)*K where the air volume Q unit is m3/h, the full pressure P unit is Pa, the power N unit is kW, and the η fan full pressure efficiency (according to Fan-related standards, the total pressure efficiency shall not be lower than 0.7, the actual estimated efficiency may be smaller, or 0.6, a small fan shall be taken as a small value, and a large fan shall be taken as a large value).

Axial flow fan: 1.05-1.1, take the large value for low power, and take the small value for high power

Selected motor power N=(Q/3600)*P/(1000*η)*K

The calculation formula of fan power P (KW) is P=Q*p/(3600*1000*η0*η1)

Q—air volume, m3/h; p—full wind pressure of fan, Pa; η0—internal efficiency of fan, generally 0.75~0.85, low value for small fan and high value for large fan η1—mechanical efficiency,

1. If the fan is directly connected to the motor, take 1;

2. Coupling connection takes 0.95~0.98;

3. Use V-belt connection to take 0.9~0.95;

4. Use flat belt drive to take 0.85

How to calculate the current of the motor: I=(motor power/voltage)*c

Power unit is KW; voltage unit: KV; C: 0.76 (power factor 0.85 and power efficiency 0.9 product)

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