Examples of troubleshooting methods for cooling fa

Examples of troubleshooting methods for cooling fans in large pump stations

(I) cooling fan shutdown fault

1 Fault phenomenon

the upper computer and basic cabinet display or alarm, and the three-phase over temperature of the main motor and the loss of air of the cooling fan alarm

2 Possible consequences

the three-phase overtemperature of the main motor caused by the fan's failure to work normally, and the pump protection tripping with unstable friction force in operation

3. Cause

(1) the fan has no power supply

(2) the fan is damaged

(3) the fan runs in phase failure

(4) the air volume switch sensor position is incorrect

(5) the fan signal line is loose and broken

(6) a phase wiring bolt in the fan is loose, causing the wiring to touch the housing

4. Troubleshooting

(1) check the power supply voltage, fuses, circuit breakers, contactors, thermal relays and connecting lines to solve the resulting power failure

(2) measure the insulation resistance of the fan, check the condition of the fan winding, and replace the damaged parts or the whole machine

(3) check the power control equipment, power lines and terminals for the above good performance of polycarbonate, and solve the phase failure caused by it

(4) adjust the position of the air volume switch sensor. Shaft sinking winch

(5) check the signal circuit, connect and sort out the signal circuit

(6) tighten the connecting bolts to solve the problem that the fan does not run

(II) abnormal sound fault of cooling fan operation

1 Fault phenomenon

the fan vibrates greatly and emits periodic friction noise

2. Cause

(1) the fan bearing is damaged and the coupling is installed incorrectly

(2) the casing or air inlet rubs against the impeller

(3) the foundation is not firm

(4) the rivets of the impeller are loose or the disc is deformed

(5) the impeller shaft disc and shaft are loose, and the coupling bolts are loose

(6) the inlet and outlet pipes of the fan are poorly installed

(7) rotor imbalance

3. Solution

(1) replace the fan bearing and adjust the concentricity of the coupling

(2) correct the installation angle of the impeller

(3) reinforce the fan foundation and tighten the loose bolts

(4) improve the installation position of fan inlet and outlet pipes

(5) the fan replacement interface is intuitive, the operation is simple, the control scheme is perfect, and the function is powerful

(III) the temperature rise of fan bearing is too high

1 Fault phenomenon

the temperature of fan housing is obviously too high

2. Cause

(1) the bearing housing vibrates violently

(2) poor quality of lubricating grease

(3) the rolling bearing is damaged

(4) the fixing tightness of bearing end frame is uneven

3. Solution

(1) adjust the installation position of the fan or replace the fan bearing

(2) clean the bearing and replace with high-quality lubricating grease

(3) replace the fan

(IV) excessive fan motor current

1 Fault phenomenon

the motor temperature is high, and the protection device and power switch often trip

2. Cause

(1) the flow is over value or the air duct leaks

(2) the gas density and pressure delivered by the fan are too high

(3) the input voltage of the motor is too low or the single-phase power supply is out of power

(4) the coupling leather ring is too tight or the gap is uneven

(5) affected by the violent vibration of the bearing housing

3. Solution

(1) check the pipe connection and repair the air leakage part

(2) check the working condition of power supply and electrical equipment, repair and replace damaged parts

(3) check the rotation of fan and motor and adjust the installation clearance

(4) replace the coupling leather ring to make it moderately tight