AIRSTAGE Technical Reference
Cassette Indoor Fan Motor Resistance Check
Models AU7, AU9, AU12, AU14 and AU18
Electrical resistance reference for confirming indoor fan motor winding condition
This procedure is used to confirm the electrical condition of the indoor fan motor for cassette-type units. Resistance measurements must be taken between the specified terminals at 20°C.
Safety: Isolate electrical power before disconnecting the motor or taking resistance measurements. Confirm the circuit is de-energised before proceeding.
Check Point 1 - Models AU7 and AU9
Fan motor part number: 9601040040
Resistance values at 20°C (±8%)
| Measurement | Resistance (Ω) |
|---|---|
| White - Red | 658 |
| Red - Black | 329 |
| Red - Violet | 99.6 |
| Violet - Blue | 99.6 |
Check Point 2 - Models AU12 and AU14
Fan motor part number: 9601040019
Resistance values at 20°C (±8%)
| Measurement | Resistance (Ω) |
|---|---|
| White - Red | 455 |
| Red - Black | 541 |
| Red - Violet | 103 |
| Violet - Blue | 103 |
Check Point 3 - Model AU18
Fan motor part number: 9601040026
Resistance values at 20°C (±8%)
| Measurement | Resistance (Ω) |
|---|---|
| White - Red | 446 |
| Red - Black | 552 |
| Red - Violet | 117 |
| Violet - Blue | 117 |
Diagnostic Notes
- All readings are specified at 20°C ambient temperature.
- If a winding is open, shorted, or significantly outside the stated tolerance, replace the indoor fan motor.
- Verify the thermal protector (140°C) has continuity before determining that the motor has failed.
- Confirm the fan rotates freely and airflow is not restricted by dirt, obstructions or mechanical drag.
Assessment guidance: Compare the measured resistance against the value for the applicable model and allow for the stated ±8% tolerance. Temperature variation can affect the measured result.
