AIRSTAGE Technical Reference
Power Relay & Diode Power Bridge Testing
Circuit checks, resistance values and replacement criteria
Use this procedure to check the power relay, Control PCB output and diode power bridge before replacing components.
Components covered: Power Relay P/No. 9900262013 and Diode Power Bridge P/No. 0100122039.
Electrical safety: Isolate power before disconnecting terminals or carrying out resistance and continuity checks. Live-voltage testing at CN12 must only be performed by appropriately qualified personnel using suitable test equipment and safe working procedures.
1. Power Relay - P/No. 9900262013
Check Point 1: Circuit connection and coil resistance
- Verify the connection at CN12 on the Control PCB (PWB ASSY).
- Measure the coil resistance across the relay terminals.
Expected coil resistance
Approximately 120 Ω
Approximately 120 Ω
If the coil is open (∞ Ω) or reads 0 Ω, replace the Power Relay.
Check Point 2: Relay operation during normal conditions
A. Relay does not operate - OPEN between COM and ON
- Confirm coil resistance is approximately 120 Ω.
- Measure DC +12 V at CN12 on the Control PCB.
- If no voltage is present, replace the Control PCB.
- If voltage is correct but the relay still does not operate, replace the Power Relay.
B. Relay does not release - always ON when all indoor units are stopped
- Exclude normal preheat operation.
- Disconnect the connector from the relay.
- Check continuity between COM-ON.
- If continuity exists while inactive, the relay contacts are stuck / welded. Replace the Power Relay.
2. Diode Power Bridge - P/No. 0100122039
Check Point 1: Circuit connection
Confirm correct terminal wiring between the ACTPM module and the diode bridge.
- BLACK (In/Out) and WHITE (In/Out) connections must be correctly connected to the outdoor fan circuit.
Check Point 2: Open / short circuit test
- Remove each terminal from the bridge rectifier.
- Measure resistance between the terminal pairs shown below.
| Read Wire | Reference Terminal | Expected Resistance |
|---|---|---|
| BLACK (Out -) | WHITE (In +) | ≥ 1 MΩ |
| BLACK (In +) | WHITE (In -) | ≥ 1 MΩ |
| BLACK (In -) | WHITE (Out +) | ≥ 1 MΩ |
| WHITE (Out +) | WHITE (In -) | ≥ 1 MΩ |
Abnormal reading: If any reading shows low resistance (short circuit) or open circuit, replace the Diode Power Bridge.
3. Summary
| Component | Check | Normal Reading | Action if Abnormal |
|---|---|---|---|
| Power Relay Coil | CN12 | 120 Ω | Replace Power Relay |
| Relay Operation | COM-ON | Opens / closes properly | Replace Relay or Control PCB |
| Diode Bridge | All terminal pairs | ≥ 1 MΩ | Replace Diode Bridge |
Technical values and replacement criteria are based on the supplied service information. Confirm model applicability before replacing components.