Honeywell 7800 Series Product Data page 28

7800 SERIES RM7896A,B,C,D RELAY MODULE
NOTE: Normal sequences are in bold type, while abnormal sequences are not in bold type.
Sequence
INITIATE
If the RM7896 is in a HOLD status, the following conditions could exist:
INITIATE HOLD: (AC Frequency/Noise)
INITIATE HOLD: (AC Line Dropout)
INITIATE HOLD: (AC Frequency)
INITIATE HOLD: (Low Line Voltage)
STANDBY
If the RM7896 is in a HOLD status, the following conditions could exist:
STANDBY HOLD: F/G (Flame Detected)
STANDBY HOLD: T7 (Airflow Interlock)
PURGE
If the RM7896 is in a HOLD condition, the following conditions could exist:
PURGE HOLD: TEST (Run/Test Switch)
PURGE HOLD: F/G (Flame Detected)
PURGE HOLD: T7 (Airflow Interlock)
PILOT IGN
65-0193
Table 6. Sequence and status hold information.
Status
The LED indicates the burner status, POWER, which is a stabilization period
for the RM7896 to check for any fluctuations in AC line voltage inputs or control
input on power-up or during normal operation. The timing of the INITIATE period is
ten seconds before entering STANDBY.
The LED indicates the burner status, POWER, and that it is waiting for excess line
noise to clear up. The burner sequence will not advance into STANDBY until the
excess line noise, which prevents sufficient reading of the line voltage inputs,
ceases or a line frequency error is corrected (perhaps caused by using a 60 Hz
device on a 50 Hz line, or vice versa).
The LED indicates the burner status, POWER, and that AC Line power has
momentarily dropped out. The burner sequence will not advance into STANDBY
until the AC line voltage has stabilized throughout the INITIATE sequence.
The LED indicates the burner status, POWER, and that line frequency is faster
than the expected value. The burner sequence will not advance into STANDBY
until the line frequency returns to the proper value (perhaps caused by using a
60 Hz device on a 50 Hz line).
The LED indicates the burner status, POWER, and that low line voltage has
occurred. The burner sequence will not advance into STANDBY until the line
voltage is at a sufficient level for proper operating parameters.
The LED indicates the burner status, POWER. The burner can be placed in
STANDBY by opening the burner switch or if the operating controller indicates its
set point has been satisfied. If a demand is present for burner operation, the
burner sequence will not advance from STANDBY to PURGE until the recycle
limits close.
The LEDs indicate the burner status, POWER and FLAME, and that a flame is
detected. A demand is present for burner operation. The burner sequence will not
advance to PREPURGE because a flame is detected as being present. The
sequence will not advance to PREPURGE until the flame signal clears. If the
flame signal does not clear within 40 seconds, the RM7896 will lockout.
The LED indicates the burner status, POWER, and that the Air-flow Interlock is
closed. A demand is present for burner operation and the burner sequence will not
advance to PREPURGE until the Airflow Interlock proves open. If this time
exceeds the 120 second hold, the RM7896B,D will lockout.
The LED indicates the burner status, POWER, and that it is the period of time
before ignition during which time the blower motor is running. The timing of the
PURGE period is selectable.
The LED indicates the burner status, POWER, and that the Run/Test Switch is in
the TEST position. The sequence will not continue until the Run/Test Switch is
placed in the RUN position (RM7896C,D).
The LEDs indicate the burner status, POWER and FLAME, and that a flame is
detected. The burner sequence will not advance through PREPURGE because a
flame is detected as being present. The sequence will hold, waiting for the flame
signal to clear. If the time exceeds 30 seconds, the RM7896 will lockout.
The LED indicates the burner status, POWER, and that the Air-flow Interlock is not
closed. The sequence will not advance to ignition until the Airflow Interlock proves
closed. If this time exceeds a 30 second HOLD, the RM7896 will lockout.
The LEDs indicate the burner status, POWER, PILOT and FLAME, which is the
period of time the RM7896 permits the pilot valve to be open and the pilot flame to
be established.
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