What are the methods for diagnosing faults in boiler flue gas exhaust fan motors?

What are the methods for diagnosing faults in boiler flue gas exhaust fan motors?

The motor is a crucial component of a boiler exhaust fan. When issues arise with this component, it directly affects the operation of the high-pressure fan. What are the methods for detecting faults in the boiler exhaust fan motor? Please refer to the following summary. (1) Visual inspection: Check whether the junction box and winding terminals are burnt. If overheated, the windings will turn dark brown and emit a distinctive odour. (2) Temperature testing method: Run the motor without load for 20 minutes, then touch various parts of the windings with the back of your hand to check whether the temperature exceeds normal levels. (3) Measurement using a live-circuit ammeter: If the current in a particular phase is excessively high, this indicates a short circuit in that phase. (4) Bridge measurement: When checking the DC resistance of each winding, the difference between them must not exceed 5. If it does, the phase with the lower resistance is short-circuited. (5) Short-circuit detection method: When the winding under test is short-circuited, the steel plate will vibrate. (6) Megohmmeter method: Measure the insulation resistance between any two phase windings. If the reading is very low or zero, it indicates a short circuit between the two phase windings. (7) Voltage drop method: Connect the three windings in series, apply a low-voltage safe alternating current, and measure the voltage drop to identify short-circuit faults in the windings. (8) Boiler flue gas fan current method: When the motor is running without load, first measure the three-phase current, then measure the two-phase current and compare the readings. If there is no change despite a change in the power supply, the phase winding with the higher current is short-circuited. The above are the methods for identifying faults in boiler flue gas fan motors. It is hoped that relevant personnel will master these methods in a timely manner.