The working principle of centrifugal fan is basically the same as that of turbine compressor. Both of them are caused by low gas flow rate and little pressure change. Generally, it is not necessary to consider the change of gas specific capacity, that is, to treat gas as incompressible fluid. The centrifugal fan can be made into two types: right-handed and left-handed. For the right rotating fan, the impeller rotates counterclockwise, known as the left rotating fan.
Commissioning requirements of centrifugal fans
1. Centrifugal fan can allow full voltage start-up or decompression, but it should be noted that the current of full voltage starting is about 5 ~ 7 times of rated current, and the starting torque is proportional to the square of voltage.
2. Check effectively whether the connection mode corresponds to the wiring diagram, check whether the voltage of the fan power supply conforms to the requirements, whether the power supply is short of phase or in the same phase, and whether the capacity of the distributor parts conforms to the requirements.
3. In the test, the number of no less than two people, one person control the power supply, observe the operation of the fan.
4. In the test, the low speed should be started first to check whether the rotation direction is correct or not. When the starting speed is high, the fan should be restarted after it is still, so as to avoid the high speed reverse rotation and cause the switch tripping.