Specifications
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SECTION VII - TROUBLE SHOOTING
HONEYWELL RM7895A,B,C,D/EC7895A,C; RM7896A,B,C,D
7800 SERIES RELAY MODULES
PRINCIPAL TECHNICAL FEATURES
The RM7895, RM7896 provides all customary flame
safeguard functions as well as significant advance-
ments in safety, annunciation, and system diagnostics.
Safety Shutdown (Lockout) Occurs if:
1. INITIATE PERIOD
a. Purge card is not installed or removed.
b. Purge card is bad.
c. Configuration jumpers have been changed (after
200 hours).
d. AC line power errors occurred, see Operation.
e. Four minute INITIATE period has been
exceeded.
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 (2nd stage) main valve terminal is ener-
gized (RM7895C,D/EC7895C; RM7896C, 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 not energized.
c. No flame present at end of PFEP.
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.
4. PILOT FLAME ESTABLISHING PERIOD (PFEP)
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 (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,D/EC7895C; RM7896C,D)
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.
f. No flame present at end of MFEP.
g. Internal system fault occurred.
h. Purge card is removed.
i. Purge card is bad.
6. RUN PERIOD
a. No flame present.
b. Airflow lockout feature is enabled and the airflow
switch opens.
c. Interrupted pilot valve terminal is energized
(RM7895C,D/EC7895C; RM7896C,D).
d. Main valve terminal is not energized.
e. Delayed (second stage) main valve terminal is not
energized (RM7895C,D/EC7895C;
RM7896C,D).
f. Internal system fault occurred.
g. Purge card is removed.
h. Purge card is bad.
OPERATION
Sequence of Operation
The RM7895A,B,C,D/EC7895A,C; RM7896A,B,C,D
has the operating sequences listed below; see Fig. 2
and 3. The RM7895A,B,C,D/EC7895A,C;
RM7896A,B,C,D LED provide positive visual indication
of the program sequence: POWER, PILOT, FLAME,
MAIN and ALARM.
Initiate
The RM7895A,B,C,D/EC7895A,B,C; RM7896A,B,C,D
Relay Module enters the INITIATE sequence when the
relay module is powered. The RM7895A,B,C,D/
EC7895A,C; RM7896A,B,C,D can also enter the INI-
TIATE sequence if the relay module verifies voltage
fluctuations of +10/-15% or frequency fluctuations of
±10% during any part of the operating sequence. The
INITIATE sequence lasts for ten seconds unless the
voltage or frequency tolerances are not met. When not
met, a hold condition is initiated and displayed on the
optional KDM for at least five seconds; when met, the
INITIATE sequence restarts. If the condition is not cor-
rected and the hold condition exists for four minutes, the
RM7895A,B,C,D/EC7895A,C; RM7896A,B,C,D locks
out.