General Assist Technical Reference
LUAK / LJBYL DIP Switch Configuration
Indoor unit, remote controller and outdoor unit settings
Reference for temperature correction, control input, auto restart, operating mode, fan speed and maximum-current settings
This article summarises the field-configurable DIP switches and jumper wires used on applicable LUAK / LJBYL systems. A star symbol (★) identifies the documented factory setting.
Safety requirement: Isolate electrical power before accessing or changing any DIP switch or jumper wire. Changes must only be completed by appropriately qualified service personnel.
1. Indoor unit settings
SW1 - Factory reserved
| Switch | Factory setting | Function |
|---|---|---|
| SW1-1 to SW1-4 | OFF ★ | Out of use. Do not adjust for field configuration. |
SW2 - Functional adjustments
| Switch | OFF | ON | Function |
|---|---|---|---|
| SW2-1 | +4 °C ★ | 0 °C | Room-temperature correction setting for heating. |
| SW2-2 | Edge ★ | Pulse | External control-input signal setting. |
| SW2-3 | Validity ★ | Invalidity | Auto-restart setting following restoration of power. |
Jumper wire settings
| Jumper | Connected | Disconnected | Function |
|---|---|---|---|
| JM1 | 0 °C ★ | +2 °C | Room-temperature correction setting for cooling. |
| JM2 | Residential ★ | Commercial | Residential or commercial operating-mode setting. |
| JM3 | Normal ★ | Heater setting | Heater setting selection. |
Temperature correction: These switches alter the control temperature reference; they do not recalibrate the sensor. Confirm the installation position, airflow and room-temperature conditions before applying a correction.
2. Remote controller settings
| Switch | OFF | ON | Function |
|---|---|---|---|
| SW1-1 / 1-2 | Switch 2 OFF ★ | Switch 1 ON ★ | Dual remote-controller setting. Match the documented master/sub arrangement when two controllers are used. |
| SW1-3 | One unit ★ | Multiple unit | Group-control setting. |
| SW1-4 | Heat & Cool model ★ | Cooling Only model | Model setting. |
| SW1-5 | Invalidity | Validity ★ | Auto-changeover setting. |
| SW1-6 | Invalidity ★ | Validity | Memory-backup setting. |
J5 - Fan-speed setting for AR90
| Jumper | Connected | Disconnected | Function |
|---|---|---|---|
| J5 | 3 speed - HI, MED, LO ★ | 1 speed - HI | Fan-speed configuration for AR90 applications. |
3. Outdoor unit maximum-current setting
The outdoor DIP switches may be used to reduce maximum current where the breaker trips during test operation because the available electrical current capacity is insufficient.
| DIP 1 | DIP 2 | DIP 3 | Maximum current | Application |
|---|---|---|---|---|
| OFF | OFF | OFF | 17.5 A | 36,000 BTU model factory setting |
| ON | OFF | OFF | 15.0 A | 30,000 BTU model factory setting |
| OFF | ON | OFF | 13.0 A | Reduced maximum-current setting |
| ON | ON | OFF | 10.5 A | Lowest documented maximum-current setting |
Critical caution: Never set a 30,000 BTU model to 17.5 A. The protection devices may activate and the unit may not operate correctly. Reducing the maximum current will also reduce cooling and heating performance.
4. Field implementation and commissioning
| 1 | Confirm the full indoor and outdoor model numbers before making changes. |
| 2 | Record the original DIP switch and jumper positions before adjustment. |
| 3 | Isolate power and verify the unit is de-energised. |
| 4 | Make only the required change and ensure each switch is fully seated in its selected position. |
| 5 | Restore power and test heating, cooling, fan operation, controller response and auto restart where applicable. |
| 6 | Document the final configuration on the commissioning or service record. |
Model verification: DIP switch arrangements can vary between production revisions. Confirm the applicable service or installation manual whenever the PCB layout or model suffix differs from this reference.