General Assist Technical Reference
J Series Indoor Unit DIP Switch Settings
Heating and cooling correction, auto restart, model coding and controller communication
Use this reference when checking or configuring applicable J Series indoor unit control PCBs.
These DIP switch settings allow fine-tuning of selected indoor unit functions, including heating and cooling temperature correction, automatic restart, remote controller custom codes and cassette draft prevention.
Important: Do not change SW3 or SW4 on site unless specifically instructed by authorised technical support. These switches define factory-configured fan characteristics and indoor unit model coding. Incorrect settings may cause abnormal operation.
1. SW1 - Heating temperature correction
| Switch | Setting | Function | Effect |
|---|---|---|---|
| SW1-1 and SW1-2 | OFF | Forbidden | Do not adjust |
| SW1-3 / SW1-4 | OFF / OFF | Heating +2 degrees C | Warmer heating correction |
| SW1-3 / SW1-4 | ON / OFF | Heating -2 degrees C | Cooler heating correction |
| SW1-3 / SW1-4 | OFF / ON | 0 degrees C | Factory default |
| SW1-3 / SW1-4 | ON / ON | Heating +4 degrees C | Maximum heating correction |
Use SW1-3 and SW1-4 to adjust the heating thermistor correction where the customer's perceived room temperature differs from the controller response.
2. SW2 - Cooling temperature correction and auto restart
| Switch | Function | Setting | Effect |
|---|---|---|---|
| SW2-1 | Cooling temperature correction | OFF: 0 degrees C ON: +2 degrees C | Adjusts the cooling temperature correction |
| SW2-2 and SW2-3 | Forbidden | OFF - factory setting | Do not adjust |
| SW2-4 | Auto restart | OFF: Invalid ON: Valid | Allows the unit to restart automatically after a power interruption |
3. SW3 - Indoor fan speed and external input
Factory configuration: SW3-1 to SW3-3 define model-specific indoor fan characteristics. Do not change these settings during normal field service.
| Model type | SW3-1 | SW3-2 | SW3-3 | Purpose |
|---|---|---|---|---|
| Cassette AU20-AU54 | Varies by capacity | Defines the model-specific fan curve | ||
| Wall mounted AS18-AS30 | Varies by model | Defines the fan motor profile | ||
| Other models | OFF | OFF | OFF | Default configuration |
SW3-4 - External input selection
OFF: Edge signal - factory setting
ON: Pulse signal
OFF: Edge signal - factory setting
ON: Pulse signal
4. SW4 - Indoor unit model code
Do not change on site: SW4-1 to SW4-4 configure the replacement PCB for the correct indoor unit capacity and model type. Each switch combination corresponds to a specific unit size, including 7, 9, 12, 14, 18, 24, 25, 30, 36, 45 and 54 type units.
Incorrect SW4 settings can cause the PCB to operate with the wrong capacity, fan profile or control logic. Confirm the required model-code setting from the applicable service documentation before replacing or configuring a PCB.
5. SW5 - Remote controller custom code and draft prevention
| Switch | Function | Setting | Description |
|---|---|---|---|
| SW5-1 / SW5-2 | Wireless remote controller custom code | OFF / OFF: Type A - factory ON / OFF: Type B OFF / ON: Type C ON / ON: Type D | Prevents one wireless remote from controlling nearby indoor units unintentionally |
| SW5-3 | Forbidden | OFF | Do not adjust |
| SW5-4 | Draft prevention - cassette only | OFF: Normal flap, 35-65 degrees ON: Draft prevention, 25-65 degrees | Changes the discharge-air angle to reduce direct cold drafts |
The wireless remote controller must be configured to the same custom code as SW5-1 and SW5-2. A mismatched code may make the indoor unit appear unresponsive to the remote controller.
6. Operational notes
| 1 | Record the original settings before making any permitted adjustment. |
| 2 | Temperature correction: Adjust SW1 and SW2 only for customer comfort tuning and only after confirming the unit, sensors and airflow are operating correctly. |
| 3 | Auto restart: Enable SW2-4 only where automatic recovery after a power interruption is required. |
| 4 | Custom code: Ensure the indoor unit and wireless remote controller use the same A, B, C or D code. |
| 5 | Power cycle: Isolate and restore power after changing a permitted DIP switch setting where required by the applicable service procedure. |
Escalation: Where the installed switch positions do not match the applicable model documentation, do not guess the correct configuration. Record the PCB part number, indoor unit model and existing switch positions, then contact authorised technical support.