Honeywell 7800 Series Installation Instructions Manual page 26

RM7890, RM7895 100 Vac
SERVICE NOTE:
A lockout condition or restart of a relay module can be accom-
plished by pressing the reset pushbutton on the relay module
or by pressing a remote reset pushbutton wired through an
optional KDM, Data ControlBus™ Module, extension cable
assembly, or remote reset module. A power-up reset module
causes an electrical reset of the relay module but does not re-
set a lockout condition.
NOTE: Normal sequences are in bold type, while abnormal sequences are in regular type.
Sequence
INITIATE
If the relay is in a HOLD status, the following conditions can exist:
INITIATE HOLD:
(AC Frequency/Noise)
INITIATE HOLD:
(AC Line Dropout)
INITIATE HOLD:
(AC Frequency)
INITIATE HOLD:
(Low Line Voltage)
STANDBY
If the relay module is in a HOLD status, the following conditions could exist:
PURGE (RM7895 only)
PURGE HOLD: F/G (Flame
Detected) (RM7895 Only)
PURGE HOLD: T7 (Airflow
Interlock) (RM7895 Only)
STANDBY HOLD: F/G
(Flame Detected)
SAFE START CHECK
(RM7890 Only)
32-00216-01
Table 14. Sequence and Status Hold Information.
The LED indicates the burner status, POWER, which is a stabilization period for the relay module
to check for any fluctuations in ac ling 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 the relay module 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
detected.
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.
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 setpoint has been satisfied. If a
demand is present for burner operation, the burner sequence will not advance from STANDBY
until the recycle limit closes.
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 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 relay module will lockout.
The LED indicates the burner status, POWER, and that the Airflow Interlock is not closed. The
sequence will not advance into ignition until the Airflow Interlock proves closed. If this time
exceeds a 30-second HOLD, the relay module will lockout.
The LED indicates 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 SAFE START
CHECK (PREPURGE in the RM7895) because a flame is detected as being present. The sequence
will not advance to SAFE START CHECK until the flame signal clears. If the flame signal does not
clear within 40 seconds, the relay module will lockout.
The LED indicates the burner status, POWER, which is the period of time after STANDBY. The
RM7890 is verifying that a flame is not present before the start of Ignition Trials. If a flame is
present, the RM7890 will recycle to STANDBY.
SERVICE NOTE:
Remove the access slot covers on the sides of the Q7800 Wir-
ing Subbase to check voltages.
WARNING
Electrical Shock Hazard.
Can cause severe injury, death or property damage.
Replace access slot covers on the Q7800B Wiring
Subbase after performing voltage checks.
Information
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