When the centrifugal fan is bent backwards, the number of the fans is not less than two. Some people control the power supply, and one person can observe the operation of the fan. If an abnormal phenomenon is found, immediately stop the inspection, first check whether the rotation direction is correct, and the centrifugal fan. After starting the operation, immediately check whether the running current of each phase is balanced and whether the current exceeds the rated current; if there is any abnormality, stop the inspection. After five minutes of operation, check whether the fan is abnormal or not, and confirm that there is no abnormal phenomenon and then start up.
When bending the centrifugal fan to test backwards, the low speed should be started first, and the rotation direction should be checked effectively. When starting the high speed, the fan must be restarted before starting to prevent the high speed reverse rotation, causing the switch to trip and the motor to be damaged. When the centrifugal fan reaches the normal speed, the input current of the fan should be measured. The operating current of the centrifugal fan cannot exceed its rated current. If the operating current exceeds its rated current, check that the supplied voltage is normal.
The electric power required to bend the centrifugal fan backwards means that under certain working conditions, the centrifugal fan and the wind chassis are effectively used, and when the air inlet is fully opened, the power required is large. If the air inlet is fully open for operation, there is a risk of damage to the motor. When testing the fan, it is best to close the valve on the inlet or outlet of the fan. After the operation, the valve is gradually opened to reach the required working condition, and the operating current of the fan exceeds the rated current.