R7120D BURNER CONTROL MODULES
66-1196EF—01
12
1.
In Pre-Purge Drive To High Fire Position
(R7120D1002), the Run/Test Switch, when placed in the
TEST position, holds in PREPURGE with the firing rate
motor in the High Fire position.
2.
In the measured PREPURGE sequence, the Run/Test
Switch, when placed in the TEST position, causes the
PREPURGE timing to stop. The firing rate motor is in
the High Fire position.
3.
In Pre-Purge Drive to Low Fire position, the Run/Test
Switch, when placed in the TEST position, holds the
burner sequence in PREPURGE 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 during the first 8 seconds when a
10-second PFEP is selected or during the first 3 seconds
when a 4-second PFEP is selected, allowing pilot-turn-
down test and other burner adjustments to be made. This
activates a 15-second flameout timer that permits pilot
flame adjustment without nuisance safety shutdowns. The
Run/Test Switch is ignored during PFEP for the
R7120D1002 if terminals 5 and 7 or 7 and 6 are
jumpered.
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 R7120 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 R7120 has site-configurable jumper options; see Fig. 10
and Table 4. If necessary, clip the site-configurable jumpers
with side cutters and remove the resistors from the Relay
Module.
Fig. 10. Selectable site-configurable jumpers.
Table 4. Site Configurable Jumper Options.
a
Pilot Valve/First Stage Oil Valve (Valve/Start) terminal 5.
b
A 30 second MFEP can be accomplished by adding a jumper wire between terminals 8 and M.
SERVICE NOTE
: Clipping and removing these site-configurable jumpers enhances the level of safety. Removal after 200 hours
of main valve operation will result in a hard lockout, Code 110.
RUN/TEST SWITCH
NOTE: CONFIGURATION JUMPERS SHOWN FOR RM7800G/RM7840G.
SELECTABLE CONFIGURATION JUMPERS
M12301
Jumper Number
Description
Intact
Clipped
R7120 Type
JR1
Pilot Flame Establishing
Period (PFEP)
10 seconds
4 seconds
All
JR2
Pilot Valve
a
/Main Flame
Establishing Period (MFEP)
10 seconds/
Intermittent
15 or 30 seconds Interrupted
b
R7120D2000 only
JR3
Start-up Interlock Check
Disabled
Enabled
All