Direct spark ignition systems – 2nd Ave. Honeywell Relay Modules 7800 Series User Manual
7800 SERIES RELAY MODULES
On the subbase, jumper L1 to the ignition
terminal; refer to the appropriate wiring diagram
to determine the proper terminal. Disconnect the
leadwire to the pilot valve if it is connected to the
Close the master switch to energize only the
If the ignition spark is not strong and continuous,
open the master switch and adjust the ignition
electrode spark gap setting to the manufacturer
Make sure the ignition electrodes are clean.
Close the master switch and observe the spark.
After a continuous spark is obtained, open the
master switch and add a jumper on the subbase
from terminal L1 power to the pilot terminal 8 or
21. Reconnect the leadwire from the pilot valve if
it was disconnected in step b.
Close the master switch to energize both the
ignition transformer and the pilot valve.
If the pilot does not ignite and if the ignition spark
is still continuous, adjust the pressure regulator
until a pilot is established.
When the pilot ignites properly and stays ignited,
open the master switch and remove the jumper(s)
from the terminals of the subbase.
Check for adequate bleeding of the fuel line.
Reinstall the 7800 Series Relay Module on the
subbase, close the master switch, and then return
to step 4.
7. When pilot ignites, measure the flame signal. If the pilot
flame signal is unsteady or approaching the 1.25 Vdc
minimum value, adjust the pilot flame size or detector
sighting to provide a maximum and steady flame signal.
8. Recycle the system to recheck lightoff and pilot flame
9. When the MAIN LED turns on, make sure the automatic
main fuel valve is open; then smoothly open the manual
main fuel shutoff valve(s) and watch for main burner
flame ignition. When the main burner flame is
established, go to step 16.
10. If the main burner flame is not established within five
seconds or the normal lightoff time as specified by the
equipment manufacturer, close the manual main fuel
11. Recycle the system to recheck the lightoff and pilot
12. Smoothly open the manual fuel shutoff valve(s) and try
lightoff again. (The first re-attempt may have been
required to purge the lines and bring sufficient fuel to
13. If the main burner flame is not established within five
seconds or the normal lightoff time specified by the
equipment manufacturer, close the manual main fuel
shutoff valves(s). Check all burner adjustments.
14. If the main burner flame is not established after two
Check for improper pilot size.
Check for excess combustion air at low fire.
Check for adequate low fire fuel flow.
Check for proper gas supply pressure.
Check for proper valve operation.
Check for proper pilot flame positioning.
15. Repeat steps 8 and 9 to establish the main burner
flame; then go to step 16.
16. With the sequence in RUN, make burner adjustments
for flame stability and Btu input rating.
17. Shut down the system by opening the burner switch or
by lowering the setpoint of the operating controller.
Make sure the main flame goes out. There may be a
delay due to gas trapped between the valve(s) and
burner. Make sure all automatic fuel valve(s) close.
18. Restart the system by closing the burner switch and/or
raising the setpoint of the operating controller. Observe
that the pilot is established during PILOT IGN and the
main burner flame is established during MAIN IGN
within the normal lightoff time.
19. Measure the flame signal. Continue to check for the
proper signal through the RUN period. Check the signal
at both High and Low Firing Rate positions and while
modulating, if applicable.
20. Run the burner through another sequence, observing
the flame signal for:
Pilot flame alone.
Pilot and main flame together.
Main flame alone (unless monitoring an
intermittent pilot). Also observe the time it takes
to light the main flame. Ignition of main flame
should be smooth.
21. Make sure all readings are in the required ranges
22. Return the system to normal operation.
After completing these tests, open the master switch
and remove all test jumpers from the subbase
terminals, limits/controls or switches.
Direct Spark Ignition Systems
This check applies to gas and oil burners not using a pilot. It
should immediately follow the preliminary inspection. Refer to
the appropriate sample block diagram of field wiring for the
ignition transformer and fuel valve(s) hookup.
Low fuel pressure limits, if used, could be open. If so,
bypass them with jumpers during this check.
1. Open the master switch.
2. Complete the normal ready-to-fire checkout of the fuel
supply and equipment as recommended by the
3. Close all manual main fuel shutoff valve(s). Check that
the automatic fuel valve(s) is closed. Make sure fuel is
not entering the combustion chamber.
4. Close the master switch and start the system with a call
for heat by raising the setpoint of the operating
controller; see the relay module sequencing. The
program sequence should start the INITIATE sequence.
5. Let the sequence advance through PREPURGE (if
applicable). Ignition spark should occur when the PILOT
LED turns on. Listen for the click of the first stage fuel
solenoid valve(s). The relay module locks out and the
ALARM LED turns on.
6. Let the 7800 Series Relay Module complete its cycle.
7. Open the manual fuel shutoff valve(s).
8. Push the reset button and the relay module recycles the
program sequence through PREPURGE (if applicable).
9. When the PILOT LED turns on, make sure that the first
stage burner flame is established. If it is, go to step 15.
10. If the first stage burner flame is not established within
four seconds, or within the normal lightoff time specified
by the equipment manufacturer, close the manual fuel
shutoff valve(s), and open the master switch.
11. Check all burner adjustments.