Heaters
Pin 1: Ion detection signal line
Pin 2: Power supply Zero line
Pin 3: Power supply for ignition fan and also the common terminal for the wind pressure detection switch
Pin 6: Normally closed terminal of the wind pressure detection switch
Pin 11: Normally open terminal of the wind pressure detection switch
Pin 4: Power supply for the first-stage solenoid valve
Pin 5: Power supply for the second-stage solenoid valve
Pin 7: Power supply for the ignition
Pin 8: Reset signal
Pin 9: Only available in LME22 (power supply for the main burner air door purge actuator)
Pin 10: Fault output
Pin 12: Power supply Fire line
Additionally,Pin 1 is the ion detection signal line. If a UV probe is needed, an additional UV probe module AGQ3 is required to achieve it.
Startup sequence for LME21 controller:
After the start switch is closed (pins 2 and 12 receive power), the controller's yellow light turns on, and simultaneously pin 3 outputs a signal. The fan starts running, and during the purge time, the wind pressure switch is checked.
Pin 11 changes from normally open to normally closed, and pin 6 changes from normally closed to normally open.
If the wind pressure switch check is successful, the fan continues purging. After the purge time ends, the yellow light starts flashing. Pin 7 outputs a signal to activate the ignition , and simultaneously pin 4 outputs a signal to open the solenoid valve for ignition. Additionally, pin 1 is used for flame detection.
If no flame is detected within 3 seconds, the controller's red light turns on to indicate a fault
output.
If a flame is detected, the controller's light turns green, indicating successful ignition.