Honeywell 7800 Series Manual page 26

RM7800E,G,L,M
OPERATION
Fig. 26—RM7800M sequence.
VFD
DISPLAY
LED
DISPLAY
BURNER
OPERATING
CONTROLS
AND
INTERLOCKS
FLAME
SIGNAL
FIRING
RATE
MOTOR
KEYBOARD DISPLAY MODULE (VFD)
The first line of the Vacuum Fluorescent Display
(VFD) provides current status of the burner sequence
(STANDBY, PURGE, PILOT IGN, MAIN IGN, RUN and
POSTPURGE), timing information (PURGE, PILOT IGN,
MAIN IGN and POSTPURGE) in minutes and seconds, hold
information (PURGE HOLD: T19) and lockout information
(Lockout, Fault Code, Message and Sequence), see Fig. 27.
The extreme right side of the first line will either be blank
or it will show a small arrow pointing to the second line
followed by a two-letter code (DI-Diagnostic Information,
Hn-Fault History Information, and EA-Expanded Annun-
ciator). When the arrow and two-letter code are displayed, it
indicates the second line is showing a selectable message
submenu. The second line will display selectable or pre-
emptive messages. A selectable message supplies informa-
tion for flame strength, system status indication, system or
self-diagnostics and troubleshooting. A preemptive message
will have parentheses around the message and supply a
detailed message to support the sequence status information.
A preemptive message can also be a lockout message. A
preemptive message will replace a selectable message to
support the sequence status information. It will also replace
a selectable message after 60 seconds if it or a lockout
message is available. The RM7800 LEDs provide positive
visual indication of the program sequence: POWER, PI-
LOT, FLAME, MAIN and ALARM.
00 00
INITIATE STANDBY PREPURGE
POWER POWER POWER
LIMITS AND BURNER CONTROLLER CLOSED
RUNNING INTERLOCKS CLOSED
INTERLOCK CHECK
PREIGNITION INTERLOCK CLOSED
SAFE START CHECK
RM7800M SWITCHING
13 15
TO
MOTOR ACTION
RM7800M
00 10 20 25
TIMED PFEP
PURGE
4 OR 10 SEC MFEP RUN
POWER POWER POWER
PILOT PILOT PILOT
FLAME FLAME FLAME
MAIN MAIN MAIN
ALARM ALARM ALARM
BURNER/BLOWER MOTOR
5
10
IGN. 5 SEC.
10 SEC. IGN./PILOT 8
INTERMITTENT PILOT VALVE
MAIN VALVE
L1
TO
6 TO
4
20
TO
5
TO 18
LOW FIRE SW.
FLAME PROVING
13
Fig. 27—Keyboard Display Module and se-
quence status LEDs (Table 3).
FIVE WIRE CONNECTOR FOR
COMMUNICATIONS, REMOTE
KEYBOARD DISPLAY AND REMOTE RESET
RUN/TEST SWITCH
SEQUENCE
STATUS
SELECTABLE
MESSAGE OR
PRE-EMPTIVE
MESSAGE
SEQUENCE
STATUS
LEDs
RESET
PUSHBUTTON
FLAME
SIMULATOR INPUT
26
00 15
POSTPURGE STANDBY
POWER POWER POWER
PILOT
FLAME
MAIN
ALARM
21
9
6
7 IC
PII
SSC
TO 15
M1926D
DI = DIAGNOSTICS
H1 = HISTORY
EA = EXPANDED
ANNUNCIATOR
FLAME CURRENT
TEST JACKS
CAPTIVE
MOUNTING
SCREW
PLUG-IN
PURGE
CARD
KEYBOARD
DISPLAY
MODULE
RELAY
MODULE
FLAME
AMPLIFIER
M7359