Common faults and causes of fans

If the fan fails during use, the cause should be identified in time, the fault should be found out in a targeted manner, and the repair and elimination should be carried out reasonably to avoid damage to the body and safety accidents.

1. Excessive vibration of the fan

1) Impeller fouling, excessive dirt, corrosion and wear cause balance failure;

2) The impeller is deformed in contact with the volute or the air duct;

3) The rivet connecting the impeller and the wheel disc is loose, and the nut fastened between the wheel disc and the shaft is loose;

4) Over-temperature deformation of the rotating body (impeller, main shaft);

5) The installation foundation of the fan is damaged, or the rigidity of the contact surface is not enough or not strong;

6) There is an error in the concentricity of the main shaft and the motor shaft, and the coupling bolt is loose;

7) The deformation of the air duct makes the operation of the fan unstable and causes resonance;

8) The mounting bolts of the motor, connecting plate, bearing seat, box body, etc. are loose;

9) The fan blades at the rear of the motor and the cooling fan blades in the connecting plate are loose;

10) The fan bearing is damaged.

2. The temperature rise of the fan bearing is too high

1) The balance of the rotating body fails, and the vibration causes heat;

2) The bearing is installed with non-specified lubricating grease or grease with poor quality, deterioration, excessive filling, dust, sticky sand, dirt, etc.;

3) The fan resistance is too large or the three-phase electricity is unbalanced, or the motor is overheated due to the low voltage;

4) The bearing cover is tightened too tightly or too loosely;

5) The two bearings are not concentric or the coupling is not concentric;

6) The bearing is damaged.

3. The current of the fan motor is too large

1) System resistance or medium density is too large;

2) The input voltage of the motor is too low or the power supply phase is cut off;

3) Vibration is violent;

4) The motor wiring is wrong.

4. The fan start switch trips

1) The impeller rotates in the opposite direction;

2) The switch capacity configuration is small or the thermal protector rating is set unreasonably;

3) The overload causes the starting current to be too large (recommended to start with reduced pressure or close the inlet regulating valve);

4) Phase loss caused by poor contact of incoming lines or the same phase; poor performance of control lines;

5) The power grid capacity is insufficient, the voltage is low, the line leaks, and the wiring pile is heated and disconnected;

6) The motor wiring is wrong, connect the Y connection to the △ connection (generally, the motor with ≤3Kw is the Y connection, and the ≥4Kw is the △ connection).