AIRSYS WPUs communicate with the controller via either a 13 wire harness (ASLLC.2, ASLLC.2.48) or a set of ethernet cables (ASLLC.2A, ASLLC.2A.48). Incorrect/loose wiring may cause the system to malfunction without giving an alarm. Wire identification for all ASLLC models is given below.
ASLLC.2
| Wire # | Function | Correct Behavior |
| 1 | Compressor Signal | When asked for compressor: 240VAC across 1 and 4 |
| 2 | Supply Fan Signal | 240VAC across 2 and 4 (always on to provide power feedback, actual speed (0-10VDC) controlled by wire 11&12) |
| 3 | Heater Signal | When asked for Heater: 240VAC across 3 and 4 |
| 4 | Signal Common | 240VAC across 4 and L1. 0V across 4 and L2. |
| 5 | Alarm Common | |
| 6 | Low Pressure Alarm | NC with 5. Opens when low pressure switch trips. |
| 7 | High Pressure Alarm | NC with 5. Opens when high pressure switch trips. |
| 8 | Air Pressure Differential Alarm | NC with 5. Opens when air pressure differential alarm trips |
| 9 | Fan O.L./AC Loss Alarm | NC with 5. Opens when Fan O.L. feedback or no power to fan |
| 10 | Damper Position | 0-10VDC across 10 and 12. 0V = fully closed. 10V = fully open |
| 11 | Supply Fan Speed | 0-10VDC across 11 and 12. 0V = stopped 10V = full speed |
| 12 | DC Ground | |
| 13 | Damper Power | 24VDC across 12 and 13 to power the damper actuator |
ASLLC.2.48
| Wire # | Function | Correct Behavior |
| 1 | Compressor Signal | When asked for compressor: 48VDC across 1 and 12 |
| 2 | AC Loss Alarm | NC with 12. Opens when power loss relay (KA1) is open |
| 3 | Heater Signal | When asked for Heater: 48VDC across 3 and 12 |
| 4 | Not used | |
| 5 | Alarm Common | |
| 6 | Low Pressure Alarm | NC with 5. Opens when low pressure switch trips. |
| 7 | High Pressure Alarm | NC with 5. Opens when high pressure switch trips. |
| 8 | Air Pressure Differential Alarm | NC with 5. Opens when air pressure differential alarm trips |
| 9 | Fan O.L./AC Loss Alarm | NC with 5. Opens when Fan O.L. feedback or no power to fan |
| 10 | Damper Position | 0-10VDC across 10 and 12. 0V = fully closed. 10V = fully open |
| 11 | Supply Fan Speed | 0-10VDC across 11 and 12. 0V = stopped 10V = full speed |
| 12 | DC Ground | |
| 13 | Damper Power | 24VDC across 12 and 13 to power the damper actuator |
ASLLC.2A, ASLLC.2A.48
| Wire # | Function | Correct Behavior |
| 1 | Compressor Signal | When asked for compressor: 24VDC across 1 and 4 |
| 2 | Supply Fan Power Detection | 5 kΩ across 2 and 4 = AC supply fan 10 kΩ across 2 and 4 = DC supply fan |
| 3 | Heater Signal | When asked for Heater: 24VDC across 3 and 4 |
| 4 | Signal Common | |
| 5 | Alarm Common | |
| 6 | Low Pressure Alarm | NC with 5. Opens when low pressure switch trips. |
| 7 | High Pressure Alarm | NC with 5. Opens when high pressure switch trips. |
| 8 | Air Pressure Differential Alarm | NC with 5. Opens when air pressure differential alarm trips |
| 9 | Fan O.L./AC Loss Alarm | NC with 5. Opens when Fan O.L. feedback or no power to fan |
| 10 | Damper Position | 0-10VDC across 10 and 12. 0V = fully closed. 10V = fully open |
| 11 | Supply Fan Speed | 0-10VDC across 11 and 12. 0V = stopped 10V = full speed |
| 12 | DC Ground | |
| 13 | Damper Power | 24VDC across 12 and 13 to power the damper actuator |