Honeywell 7800 Series Manual page 19

Fig. 16—RM7895C,D sequence.
LED
DISPLAY
BURNER
OPERATING
CONTROLS
AND
INTERLOCKS
FLAME
SIGNAL
b. Main Flame Establishing Period (MFEP):
1. After the Ignition Trials, and with the presence of
flame, the main fuel valve, terminal 9, is powered. If a
flameout occurs, the RM7895A,B will lockout or
recycle within .8 or 3 seconds, depending on the Flame
Failure Response Time (FFRT) of the amplifier.
2. The RM7895C,D has a ten second MFEP. After the
Ignition Trials, and with the presence of flame, the
main fuel valve, terminal 9, is powered. If a flame-
out occurs, the RM7895C,D will lockout within .8
or 3 seconds, depending on the Flame Failure Re-
sponse Time (FFRT) of the amplifier.
RUN
1. The RM7895C,D has a delayed main valve. The
delayed main valve is energized once the RUN period is
entered. A ten second stabilization period occurs.
2. The RM7895 is now in RUN and will remain in RUN
until the controller input, terminal 6, opens, indicating that the
demand is satisfied or a limit has opened.
Fig. 18—Sequence status LEDs.
BURNER SEQUENCE:
INITIATE STANDBY
POWER
POWER
PILOT
PILOT
FLAME
FLAME
MAIN MAIN
ALARM
ALARM
00 00
INITIATE STANDBY START
POWER POWER POWER
LIMITS AND BURNER CONTROLLER CLOSED
AIRFLOW SW. CHECK
2
SAFE START CHECK
FOR RM7895C1020 (ONLY), INGITION TERMINAL 10 IS DE-ENERGIZED WHEN FLAME IS PROVEN.
1
2
AIRFLOW SWITCH CHECK FEATURE IS FOR THE RM7895D.
STANDBY: PURGE
F/G HOLD HOLD: F/G
(FLAME (FLAME
PURGE
DETECTED) DETECTED)
POWER
POWER POWER
PILOT
PILOT PILOT
FLAME FLAME
FLAME
MAIN MAIN
MAIN
ALARM ALARM
ALARM
00 10
TIMED PFEP
PURGE 4 OR 10 SEC
MFEP
POWER POWER POWER
PILOT PILOT PILOT
FLAME FLAME FLAME
MAIN MAIN MAIN
ALARM ALARM ALARM
BURNER/BLOWER MOTOR
10
IGN.
1
10 SEC. IGN./PILOT
8
MAIN VALVE
DELAYED MAIN VALVE
L1
AIRFLOW INTERLOCK CLOSED 6
FLAME PROVING
Fig. 17—Sequence status LEDs.
RUN/TEST SWITCH
(RM7896C,D)
SEQUENCE
STATUS
LEDs
RESET
PUSHBUTTON
FLAME
SIMULATOR INPUT
RUN
(RM7895A,B
MAIN
INTERMIT-
PILOT
IGNITION IGNITION
TENT PILOT)
POWER
POWER POWER
PILOT
PILOT PILOT
FLAME
FLAME FLAME
MAIN
MAIN MAIN
ALARM
ALARM ALARM
19
RM7895A,B,C,D
10 15
RUN STANDBY
POWER POWER
PILOT
FLAME
MAIN
ALARM
4
9
21
TO 6
TO 7
AFSC
SSC
M5114F
CAPTIVE
MOUNTING
SCREW
PLUG-IN
PURGE
CARD
DUST
COVER
RELAY
MODULE
FLAME
AMPLIFIER
FLAME CURRENT
TEST JACKS
RUN
(RM7895C,D
INTERRUP- RESET/
TED PILOT) ALARM
POWER POWER
PILOT PILOT
FLAME FLAME
MAIN MAIN
ALARM ALARM
M3356
65-0086—2
OPERATION
M7552