Honeywell RM7895A1048 - Relay Module Assembly and Operation; Exploded View of Relay Module; Operating Sequence Stages

11 32-00156-03
RM7895A,B,C,D/EC7895A,C; RM7896A,C,D7800 SERIES Relay Modules
HONEYWELL
POWER
PILOT
FLAME
MAIN
ALARM
RESET
DUST
COVER
PURGE
TIMER
WIRING
SUBBASE Q7800A1005/U SHOWN
SUBBASE
CAPTIVE
MOUNTING
SCREW
RUN/TEST (C,D ONLY)
SWITCH
CONFIGURATION
JUMPERS
RELAY
MODULE
SEQUENCE
STATUS
LED PANEL
RESET
BUTTON
FLAME
AMPLIFIER
BURNER CONTROL
Fig. 4. RM7895A,B,C,D/EC7895A,C; RM7896A,B,C,D Relay Module, exploded view.
2. STANDBY PERIOD
a. Airflow lockout feature is enabled and the airflow switch
does not close after ten seconds or within the specified
purge card timing.
b. Flame signal is detected after 30 seconds.
c. Ignition/pilot valve/intermittent pilot valve terminal is
energized.
d. Main valve terminal is energized.
e. Delayed main valve terminal is energized
(RM7895C,D).
f. Internal system fault occurred.
g. Purge card is removed.
h. Purge card is bad.
3. PREPURGE PERIOD
a. Airflow lockout feature is enabled and the airflow switch
opens.
b. Ignition/pilot valve terminal is energized.
c. Main valve terminal is energized.
d. Delayed main valve terminal is energized (RM7895C,D).
e. Internal system fault occurred.
f. Purge card is removed.
g. Purge card is bad.
h. Flame signal is detected.
4. PILOT FLAME ESTABLISHING PERIOD (PFEP)
a. Airflow lockout feature is enabled and the airflow switch
opens.
b. No flame signal at end of PFEP.
c. Ignition/pilot valve/intermittent pilot valve terminal is
not energized.
NOTE: For the RM7895C1020/2020 and
RM7896C1036/2036, during the first 8 seconds of
PFEP, when a flame signal is detected, terminal 10 is
de-energized. If the flame signal is lost, terminal 10
will re-energize.
d. Main valve terminal is energized.
e. Delayed (second stage) main valve terminal is energized
(RM7895C,D/EC7895C; RM7896C,D).
f. Internal system fault occurred.
g. Purge card is removed.
h. Purge card is bad.
5. MAIN FLAME ESTABLISHING PERIOD (MFEP)
(RM7895C, RM7896C,D; EC7895C)
a. Airflow lockout feature is enabled and the airflow switch
opens.
b. Ignition terminal is energized.
c. Ignition/pilot valve terminal is not energized.
d. Main valve terminal is not energized.
e. Delayed main valve terminal is energized.