1. Check the power supply and fuses
Confirm the power supply voltage is normal. Use a multimeter to measure the input voltage.
Check if the corresponding fuse is blown. Replace with a fuse of the same specification if necessary.
2. Visual and auditory inspection
Observe the blower motor casing for burn marks or unusual odors. Check if the fan blades are deformed or stuck.
Pay attention for abnormal noise or vibration during startup, which may indicate bearing wear or impeller imbalance.
3. Motor and fan inspection
After disconnecting the power, remove the blower assembly and check if the blower motor windings are overheating or show obvious damage.
Use a multimeter to measure the motor resistance to determine if there is a short circuit or open circuit.
4. Control circuit and sensors
Check the control module, relays, switches, and wiring connections for looseness or corrosion.
If equipped with a frequency converter, confirm that the inverter's output frequency matches the set value.
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