Honeywell 7800 Series Installation Instructions Manual page 34

RM7888A 7800 SERIES RELAY MODULE
a
This minimum or stronger signal should be obtained easily if the detector is correctly installed and positioned to prop-
erly sense the flame. This voltage must be obtained before completing checkout.
b
The flame signal amplifier circuitry is tested one-half second every five seconds during burner operation and shuts
down the burner if the amplifier fails (all installations).
c
The flame amplifier is an Ampli-Check™ type.
Measure the flame signal at the appropriate times defined
in the following checkout tests. Read the flame signal in
volts dc at the flame amplifier test jacks + and -(Com).
1. Use a 1 Megohm/volt meter with a 0 to 10 Vdc capa-
bility.
2. Set the 1 Megohm/volt meter to the 0 to 10 Vdc
range.
3. Insert the positive (red) probe into the + jack of the
flame amplifier. Insert the negative (black) probe
into the - (Com) jack of the flame amplifier (see Fig.
25).
4. Allow a few seconds for the meter reading to stabi-
lize.
5. If using AMPLI-CHECK™ or shutter check amplifiers,
read the average stable voltage, disregarding the
peaks caused by the self-checking operation.
6. The meter reading must be as specified in Table 11
after all tests are completed and all adjustments
made.
As an option, the flame signal can be checked by using the
optional Keyboard Display Module. If the signal is
unstable or less than the minimum acceptable voltage,
check the flame detector installation and circuitry.
1. Check the supply voltages at terminals 4 (L1) and L2
(N). Make sure the master switch is closed, connec-
tions are correct, and the power supply is of the cor-
rect voltage, frequency and is sinusoidal.
2. Check the detector wiring for defects including:
• Incorrect connections.
• Wrong type of wire.
• Deteriorated wire.
• Open circuits.
• Short circuits.
• Leakage paths caused by moisture, soot or
accumulated dirt.
3. For a flame rod, make sure:
• There is enough ground area.
• The flame rod is properly located in the flame.
• The temperature at the flame rod insulator is no
greater than 500° F (260° C).
4. For all optical detectors, clean the detector viewing
window and inside of the sight pipe as applicable.
5. With the burner running, check the temperature at
the detector. If it exceeds the detector maximum
rated temperature:
• Add a heat block to stop conducted heat traveling
up the sight pipe.
• Add a shield or screen to reflect radiated heat.
• Add cooling (refer to sight pipe ventilation in the
detector Instructions).
6. Make sure that the flame adjustment is not too lean.
7. Make sure that the detector is properly sighting the
flame.
8. If necessary, resight or reposition the detector.
32-00214—01
Initial Lightoff Check for Proved
Pilot
Perform this check on all installations that use a pilot. It
should immediately follow the preliminary inspection.
NOTE: Low fuel pressure limits, if used, could be open. If
so, bypass them with jumpers during this check.
1. Open the master switch.
2. Make sure that the manual main fuel shut off
valve(s) is closed. Open the manual pilot shutoff
valve. If the pilot takeoff is downstream from the
manual main fuel shutoff valve(s), just very slightly
open the manual main valve to supply pilot gas flow.
Make sure the main fuel is shut off just upstream
from the burner inlet, or disconnect power from the
automatic main fuel valve(s).
3. Verify the combustion chamber has been properly
purged.
4. Close the master switch and start the system by
energizing terminal 6 (Special Function 1). See
RM7888A Sequence of Operation. The program
sequence should start the ten second INITIATE
sequence.
5. Ignition spark should occur and the pilot should
light. If the pilot ignites, the FLAME LED will be ener-
gized. Proceed to step 8.
6. If the pilot flame is not established in ten seconds,
safety shutdown occurs. Let the sequence complete
its cycle. Consult the equipment operating manual
for further information.
7. Push the reset pushbutton, and let the system recy-
cle once. If the pilot still does not ignite, make the
following ignition/pilot adjustments:
a. Open the master switch and remove the
RM7888A from the subbase.
b. On the subbase, jumper terminal 4 to ignition
terminal 10.
c. Close the master switch to energize only the igni-
tion transformer.
d. If the ignition spark is not strong and continuous,
open the master switch and adjust the ignition
electrode spark gap setting to the manufacturer
recommendations.
e. Make sure the ignition electrodes are clean.
f. Close the master switch and observe the spark.
g. After a continuous spark is obtained, open the
master switch and add a jumper on the subbase
from terminal. 4 (L1) to the pilot terminal 8.
h. Close the master switch to energize both the
ignition transformer and the pilot valve.
i. If the pilot does not ignite and if the ignition
spark is still continuous, adjust the pressure reg-
ulator until a pilot is established.
j. When the pilot ignites properly and stays ignited,
open the master switch and remove the jumpers
from terminals 4 to 8 and 4 to 10 of the subbase.
k. Check for adequate bleeding of the fuel line.
34