Honeywell 7800 Series Manual page 30

RM7885A
TROUBLESHOOTING
NOTE: Normal sequences are in bold type, while abnormal sequences are not in bold type.
Sequence
INITIATE
NOTE: The ALARM LED and Alarm output will exist until flame has been proven after the Safe-Start Check.
If the RM7885A 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 RM7885A is in a HOLD status, the following conditions could exist:
STANDBY HOLD: F/G (Flame Detected)
Shutter Check Amplifiers only:
SAFE-START CHECK
PILOT IGN
TABLE 6—SEQUENCE AND STATUS HOLD INFORMATION.
Explanation
The LED indicates the burner status, POWER, which is a
stabilization period for the RM7885A to check for any fluc-
tuations in AC line voltage inputs or control input on power-
up or during normal operation. The timing of 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 se-
quence 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
will be in STANDBY after INITIATE and waiting for the
Start command or the Stop Switch to be pressed. If a Start
demand is present for burner operation, the burner sequence
will not advance from STANDBY to PILOT IGNITION until
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 PILOT
IGNITION because a flame is detected as being present. The
sequence will not advance to PILOT IGNITION until the
flame signal clears.
If a flame or flame simulating condition occurs after an
accumulated 40 seconds of a no flame condition in
STANDBY, the fault will not be detected until SAFE-START
CHECK.
The LED indicates the burner status, POWER, which is the
period of time after STANDBY. The RM7885A is verifying
that a flame is not present before the start of Ignition Trials. If
a flame is present, the RM7885A will hold.
The LEDs indicate the burner status, POWER, PILOT and
FLAME, which is the period of time the RM7885A permits
the pilot valve to be open and the pilot flame should be
established.
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