9
Res. D Series
9
Normal Heating Sequence (cont.)
7. Steady state operation.
During steady state operation, the control monitors:
Thermostat temperature sensor
-when set point temperature is satisfied, gas
valve is shut down and damper is powered closed. The gas control LED flashes a
short flash once every 4 seconds (idle) status code.
Damper Position
-if the damper position is altered during a call for heat, the pilot
and main valves are shutdown. The damper is powered open attempting to close
the damper safety circuit. The gas control LED flashes 3 times with a 3 second
pause.
Flame sensor
-if flame is lost, pilot & main valves are shut down. The damper is
powered open. The gas control attempts to re-light the pilot 4 times. If
unsuccessful, the damper is closed, and the gas control proceeds to a 5 minute
lockout. The gas control re-attempts to light the pilot starting at normal heating
sequence #2.
8. Thermostat satisfies. (Gas Control LED flashing once every 4 seconds).
9. Burner off.
10. Damper Powered Closed (15 seconds).
Abnormal Operation
1. Flammable Vapor Sensor Fault:
a.
If the resistance is greater than 70,000 Ohms-
the gas control immediately
turns off all outputs. The gas control waits and monitors resistance for 30
seconds. If the resistance is greater than 65,000 ohms after 30 seconds, the
gas control proceeds to verify resistive delay for 2 minutes and flashes 7
times, then 1 time with a three second pause. This process is repeated 5
times until the control either returns to normal operation or proceeds to
flammable vapor lockout.
b.
If the resistance is below 3000 Ohms-
The gas control immediately turns
off all outputs and proceeds to flash 8 times, then 1 time with a three second
pause. The status self clears if the resistance returns to normal range for at
least 15 seconds.
2. Temperature Sensor Fault:
a.
Temperature sensor open circuit
–The gas control immediately turns off all
outputs and proceeds to flash 8 times then, 3 times with 3 second pause.
The status self clears if the fault clears for at least 15 seconds.
b.
Thermal well sensor not reading the same temperature within ±5.5°F
–
The gas control immediately turns off all outputs and proceeds to flash 8
