Settings And Adjustments - Honeywell 7800 Series Installation Instructions Manual

a. Configuration jumper JR2 intact:
(1) Main valve terminals 9 and 17 are energized.
(2) After a 10 second (15 second for RM7838C)
MFEP, the RM7838 is in Run with the Pilot
Valve (terminal 8) energized.
b. If configuration jumper JR2 is clipped.
(1) RM7838B - 10 seconds after terminals 9 and
17 are energized, the pilot valve terminal 8 is
de-energized.
(2) RM7838C - 15 seconds after terminals 9 and
17 are energized, the pilot valve, terminal 8 is
de-energized.
c. If the flame signal is lost during the MFEP, safety
shutdown occurs and the ALARM sounds.
Run
1. The RM7838B,C releases the firing rate motor to
modulation (terminals 13 and 15 are closed).
2. The RM7838B,C is now in RUN and remains in RUN
until the controller input, terminal 6, opens (burner
control opens, Stop Switch is pushed, running
interlocks open, a limit opens). The gas valves and
combustion fan are de-energized. (Unless
Postpurge option is chosen or VPS test is "Both" or
"Split.")
3. The Pre-Ignition Interlock must close five seconds
after terminal 6 opens or a lockout will occur. (Will be
ignored during Valve On time if VPS option is
chosen.)
4. The RM7838B,C will now begin the next purge time
cycle.
Postpurge
If configured, the RM7838B,C will complete a Postpurge
immediately following the terminal 6 interruption. The
Pre-Ignition Interlock (terminal 20) must close within five
seconds if a safety lockout occurs. Upon completion of the
Postpurge, the RM7838B,C will conduct the next purge
cycle. VP, if Both, Split, or After are configured, will run
concurrent with Postpurge. If no Postpurge, VP will
complete before starting the next purge cycle. Note the
combustion blower (terminal 5) will remain energized until
VP is complete.
Run/Test Switch
The Run/Test Switch is located on the top side of the
RM7838B,C, see Fig. 25. The Run/Test Switch allows the
burner sequence to be altered as follows:
1. In Prepurge Drive to High Fire position, the Run/Test
Switch, when placed in the TEST position, holds in
PURGE with the firing rate motor in the High Fire
position.
2. In the measured PURGE sequence, the Run/Test
Switch, when placed in the TEST position, causes the
PURGE timing to stop. The firing rate motor is in the
High Fire position.
3. In Purge Drive to Low Fire position, the Run/Test
Switch, when placed in the TEST position, holds the
burner sequence in PURGE with the firing rate motor
in the Low Fire position.
4. In PFEP, the Run/Test Switch, when placed in the
TEST position, stops the timer, allowing pilot-turn-
down test and other burner adjustments to be made.
RM7838B, RM7838C 7800 SERIES RELAY MODULES
This activates a 15 second flameout timer that
permits pilot flame adjustment without nuisance
safety shutdowns.
5. During Run, the Run/Test Switch, when placed in the
TEST position, drives the firing rate motor to the Low
Fire position.
NOTE: When the RM7838B,C is switched to the TEST
mode, it stops and holds at the next Run/Test
Switch point in the operating sequence. Make
sure that the Run/Test Switch is in the RUN
position before leaving the installation.
SETTINGS AND
ADJUSTMENTS
Selectable Site-Configurable
Jumpers
The RM7838B,C has a two site-configurable jumper
option; see Fig. 27 and Table 8. If necessary, clip the site-
configurable jumper with side cutters and remove the
resistors from the Relay Module.
SELECTABLE SITE-CONFIGURABLE JUMPERS
Fig. 27. Selectable site-configurable jumpers.
Table 8. Site Configurable Jumper Options.
Jumper
Number Description
JR1 Pilot Flame
Establishing Period
(PFEP)
JR2 Pilot Type
JR3 Fan for VPS
JR3 applies when Before, Split, or Both VP feature is
enabled on the RM7838B,C.
To conduct Valve Proving during purge, power on terminal
7 is required.
21
M32335
Intact Clipped
10 4 seconds
seconds
Intermit. Interrupt.
Disabled Enabled
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