Honeywell 7800 SERIES Manual page 26

RM7890A,B,C
TROUBLESHOOTING
NOTE: Normal sequences are in bold type, while abnormal sequences are not in bold type.
Sequence
INITIATE
If the RM7890 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 RM7890 is in a HOLD status, the following conditions could exist:
STANDBY HOLD: F/G
(Flame Detected)
SAFE START CHECK
PILOT IGN
RUN
RESET/ALARM TEST
65-0126—2
TABLE 6—SEQUENCE AND STATUS HOLD INFORMATION.
The LED indicates the burner status, POWER, which is a stabilization period for
the RM7890 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 the RM7890 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 50
Hz device on a 60 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 SAFE START CHECK
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 SAFE START CHECK 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 RM7890 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.
The LEDs indicate the burner status, POWER, PILOT and FLAME, which is the
period of time the RM7890 permits the pilot valve and ignition to be energized
and the pilot flame to be established.
The LEDs indicate the burner status, POWER, PILOT, FLAME and MAIN,
which is the period of time after the Ignition Trials and before the operating
controller set point is reached. During this time, the burner is firing under the
control of the operating controller.
The LED indicates the burner status, POWER and ALARM. This condition
indicates that the reset pushbutton is pressed. If it is held for more than four
seconds, the alarm output is energized. The alarm output will be de-energized
after the reset pushbutton is released.
Information
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