General Assist Technical Reference
J-Series VRF Outdoor Fan Motor Testing
Part No. 9601705017 — Motor Induct
Diagnostic procedure for checking wiring, winding resistance, power supply and physical condition of the outdoor fan motor assembly.
Electrical safety: These checks involve mains-voltage circuits. Isolate power before disconnecting connectors or measuring resistance. Live voltage measurements must only be carried out by appropriately qualified personnel using suitable test equipment and safe work practices.
Purpose: Use this procedure to verify whether an outdoor fan fault is caused by the motor itself, its wiring/connectors, the fan capacitor, the control PCB supply, or a physical airflow restriction.
1. Check the circuit connections
- Inspect the wiring path from Control PCB CN2 → joint connector → fan motor.
- Confirm the fan capacitor connections, including the Yellow / Black leads.
- Verify CN11 (AC-IN) and CN35 (CT / communication) are fully seated and secure.
- Confirm the DC 12 V control signal from the control board is present where applicable.
2. Check fan motor winding resistance
With power isolated and the motor disconnected as required, measure resistance between the following wires:
| Winding | Measure Between | Expected Resistance |
|---|---|---|
| Main A | White (1) – Red (2) | 45.0 Ω ±5% |
| Main B | Red (2) – Blue (3) | 59.5 Ω ±5% |
| Auxiliary | Red (2) – Black | 22.5 Ω ±5% |
Replace the fan motor if: a winding is open circuit, short circuit, or the measured resistance is outside the stated ±5% range after allowing for meter lead resistance and temperature conditions.
3. Check the fan motor power supply
- Measure the output voltage at CN2 on the control PCB.
- Expected reading: AC 220 V ±20 V between CN2(2) and CN1(2) when standby power is present.
- If the reading is 0 V, check the AC input connection at CN1 and confirm the main power supply before condemning the fan motor.
4. Check the fan and airflow path
- Confirm the fan rotates freely and there is no mechanical interference.
- Check for dirt, debris or foreign material around the fan and heat exchanger.
- Confirm installation clearances are not restricting air intake or discharge.
- Check for abnormal vibration, bearing noise or evidence of the fan wheel contacting the housing.
5. Quick reference
| Test | Normal Result | If Incorrect |
|---|---|---|
| CN2 power output | 220 ±20 V AC | Check CN1 AC input, mains supply and control PCB. |
| Motor winding resistance | Within ±5% of specified values | Replace fan motor if wiring and connections are confirmed good. |
| Fan operation | Smooth start-up, no abnormal vibration or noise | Inspect motor, fan wheel, bearings and mounting. |
| Airflow path | Clear and unobstructed | Remove blockage and correct installation clearance issues. |
6. Diagnostic sequence
- Confirm the fan is physically free to rotate and the airflow path is clear.
- Isolate power and inspect all motor, capacitor and PCB connectors.
- Measure the motor winding resistance.
- If the motor readings are correct, restore power and perform the required live voltage checks.
- Use the results to determine whether the fault is with the motor, wiring, capacitor, power supply or control PCB.
Service note: Do not replace the fan motor solely because the fan is not operating. Confirm the motor winding resistance, control PCB output, connectors, capacitor and mechanical condition first.