20
SERVICE NOTE: Clipping and removing a site-
configurable jumper enhances the level of safety.
RM7895A,B,C,D
OPERATION
See Table 6 for further details of Hold conditions.
RUN/TEST SWITCH FUNCTIONS
The Run/Test Switch is located on the top side of the
RM7895C,D, see Fig. 17. The Run/Test Switch allows the
burner sequence to be altered as follows:
1. In the measured PREPURGE sequence, the Run/Test
Switch, when placed in the TEST position, causes the
PREPURGE timing to stop.
2. In Pilot Flame Establishing Period, the Run/Test
Switch, when placed in the TEST position, stops the timer
during the first eight seconds of a ten second PFEP selec-
tion or during the first three seconds of a four second PFEP
selection. It also allows for pilot-turn-down test and other
burner adjustments. This activates a fifteen second flame-
out timer that permits pilot flame adjustment without nui-
sance safety shutdowns. The Run/Test Switch is ignored
during PFEP for RM7895C,D if terminals 8 and 9 or 9 and
21 are jumpered.
NOTE: When the RM7895C,D 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.
WARNING
Do not use the Run/Test Switch during Pilot
Flame Establishing Period for the RM7895C,D
when using direct spark ignition.
SELECTABLE SITE-CONFIGURABLE JUMPERS
The RM7895 has three site-configurable jumper options,
see Fig. 19 and Table 3. The site-configurable jumpers should
be clipped with side cutters and the resistors removed from
the Relay Module.
TABLE 3—SITE CONFIGURABLE JUMPER OPTIONS.
Jumper Number
Description
Intact
Clipped
RM7895 Type
JR1
a
Pilot Flame Establishing Period
10 seconds
4 seconds
(ALL)
JR2
Flame Failure Action
Recycle
Lockout
(ALL)
JR3
Airflow Switch (ILK) Failure
Recycle
Lockout
(ALL)
a
The RM7895C1020 has a fixed pilot flame establishing period of ten seconds. The model does not have jumper JR1.
Fig. 19—Selectable site-configurable jumpers.
STATIC CHECKOUT
CAUTION
1. Use extreme care while testing the system. Line
voltage is present on most terminal connections
when power is on.
2. Open the master switch before installing or
removing a jumper on the subbase.
3. Before continuing to the next test, be sure to re-
move test jumper(s) used in the previous tests.
4. Replace all limits and interlocks not operating
properly. Do not bypass limits and interlocks.
5. Close all manual fuel shutoff valve(s) before
starting these tests.
After checking all wiring, perform this checkout before
installing the RM7895 on the subbase. These tests verify the
Q7800 Wiring Subbase is wired correctly, and that the exter-
nal controllers, limits, interlocks, actuators, valves, trans-
formers, motors and other devices are operating properly.
NOTE: Do not perform a dielectric test with the RM7895
installed. Internal surge protectors will break down and
conduct a current. This could cause the RM7895 to fail the
dielectric test or possibly destroy the internal lightning
and high current transient protection components.
EQUIPMENT RECOMMENDED
1. Voltmeter (20 kohm/volt minimum sensitivity) set on
the 0-300 Vac scale.
2. Two jumper wires; no. 14 wire, insulated, 12 inches
(304.8 mm) long, with insulated alligator clips at both ends.
!
!
RUN/TEST SWITCH
(RM7896C,D)
SELECTABLE CONFIGURATION JUMPERS
M7553
