General Assist Technical Reference
Indoor Unit PCB Model Code - SW4 DIP Switch Settings
PCB replacement / model-code setup
When replacing an indoor unit control PCB, refer to the original control board for the correct DIP switch settings. Also ensure that SW4 matches the model code shown on the unit serial number plate.
What SW4 Does
SW4 is used to set the indoor unit model-code information on the replacement PCB.
Important: Do not rely on a generic PCB setting. Match SW4 to the actual indoor unit model code on the serial number plate.
SW4 DIP Switch Settings by Model Code
| Switch | 54 | 45 | 36 | 30 | 25(24) | 20(22) | 18 | 14 | 12 | 9 | 7 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| SW4-1 | OFF | ON | OFF | ON | OFF | ON | OFF | ON | OFF | ON | OFF |
| SW4-2 | ON | OFF | OFF | ON | ON | OFF | OFF | ON | ON | OFF | OFF |
| SW4-3 | OFF | OFF | OFF | ON | ON | ON | ON | OFF | OFF | OFF | OFF |
| SW4-4 | ON | ON | ON | OFF | OFF | OFF | OFF | OFF | OFF | OFF | OFF |
PCB Replacement Procedure
- Before removing the original PCB, record the existing DIP switch settings.
- Confirm the indoor unit model code from the serial number plate.
- Fit the replacement PCB.
- Set SW4-1 to SW4-4 according to the model-code table above.
- Match any other relevant DIP switch settings to the original PCB.
- Recheck all switch positions before restoring power.
Important: Incorrect SW4 settings can cause the replacement PCB to identify the indoor unit as the wrong model/capacity. Always verify the serial-plate model code before commissioning the replacement board.