151B0801 R5 3/28/2006
18
R7184 DETAILED SEQUENCE OF OPERATION
Power is applied to unit. The R7184 completes a self-diagnostic procedure. If no light or flame is present, and unit
passes its self-diagnostic procedure, the control enters into the idle mode.
Thermostat calls for heat
:
A) Safety check is made for flame (4 second delay).
1) If flame is not present, the R7184 will apply power to the burner motor and igniter.
2) If flame is present, the control remains in the idle state.
B) Unit enters a pre-purge period of 15 seconds.
C) After 10 seconds, control checks for flame presence.
1) If flame is not present, the R7184 enters the trial for ignition state.
2) When flame is present, the control enters lock out mode.
D) Control monitors the burner flame.
1) When flame is present, the control enters ignition carryover state. (Continues to spark for 10 sec.).
a) Provides continuous spark after flame is sensed to assure that burner remains lit.
b) Turns on LED diagnostic light.
c) Starts carryover timer.
(i)
Flame and call for heat are monitored.
•
If flame is lost and lockout timer has not expired, R7184 will return to trial for ignition state.
•
If flame is lost and lockout timer has expired, R7184 will enter the recycle state.
♦
Recycle timer starts.
♦
Burner motor and igniter and solenoid valve are turned off.
♦
LED diagnostic light flashes slowly.
E) Carryover timer expires.
1) Enters run state.
a) Igniter turns off.
Combustion continues until thermostat is satisfied, or R7184 detects a loss of flame and enters into Recycle Mode.
F) Thermostat is satisfied - call for heat is terminated:
a) R7184 shuts off burner motor and solenoid valve.
(i)
If control utilizes a blower motor off delay, after 30 seconds, flame presence is checked.
•
If flame is not present, the R7184 LED diagnostic light is off and returns to idle state.
If flame is presence is detected, the control enters lock out mode.
