Troubleshooting - Honeywell 7800 Series Installation Instructions Manual

RM7888A 7800 SERIES RELAY MODULE
check for proper detector operation, check the FFRT and
conduct Safety Shutdown Tests under all operating
conditions.
Flame Signal with Hot Combustion
Chamber (All Installations)
With all initial start-up tests and burner adjustments
completed, operate the burner until the combustion
chamber is at the maximum expected temperature.
Observe the equipment manufacturer warmup
instructions. Recycle the burner under these hot
conditions and measure the flame signal. Check the pilot
alone, the main burner flame alone, and both together
(unless monitoring only the pilot flame when using an
intermittent pilot, or only the main burner flame when
using DSI). Check the signal at both the High and Low
Firing Rate positions and while modulating, if applicable.
Check the FFRT of the Flame Amplifier. Lower the set point
of the operating controller and observe the time it takes
for the burner flame to go out. This should be within .8 or 3
seconds maximum depending on the amplifier selected.
If the flame signal is too low or unsteady, check the flame
detector temperature. Relocate the detector if the
temperature is too high. If necessary, realign the sighting
to obtain the proper signal and response time. If the
response time is still too slow, replace the Plug-In Flame
Signal Amplifier. If the detector is relocated or re sighted,
or the amplifier is replaced, repeat all required Checkout
tests.
Safety Shutdown Tests (All
Installations)
Perform these tests at the end of Checkout, after all other
tests have been completed. If used, the external alarm
should turn on. Press the RM7888A reset pushbutton to
restart the system.
1. Opening a Limits Complete interlock during PILOT
IGN, MAIN IGN or RUN period. (Safety shutdown will
occur.)
2. Detection of flame 40 seconds after entry to
STANDBY.
a. Simulate a flame to cause the flame signal volt-
age level to be at least 1.25 Vdc for 240 seconds
after entry to STANDBY.
b. Safety shutdown will occur.
3. Failure to ignite pilot.
a. Close the pilot and main fuel manual shutoff
valve(s).
b. Depress the reset button.
c. Start the system.
d. The automatic pilot valve(s) should be energized
but the pilot cannot ignite.
e. Safety shutdown will occur.
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4. Failure to ignite main.
a. Open the manual pilot valve(s); leave the main
fuel manual shutoff valve(s) closed.
b. Depress the reset button.
c. Start the system.
d. The pilot should ignite and the flame signal
should be at least 1.25 Vdc but the main burner
cannot light.
e. Energize the appropriate special function input
(terminal 17, 19 or 20) to sequence to RUN. See
the RM7888A Sequence of Operation.
f. The flame signal should drop below 1.25 Vdc
within .three or eight seconds (depending on the
FFRT of the amplifier) after the pilot goes out.
g. Safety shutdown will occur.
5. Loss of flame during RUN.
a. Open the main fuel manual shutoff valve(s) and
open the manual pilot shutoff valve(s).
b. Depress the reset button.
c. Start the system. Start-up should be normal and
the main burner should light normally.
d. Energize the appropriate special function input
(terminal 17, 19 or 20) to sequence to RUN. See
the RM7888A Sequence of Operation.
e. After the sequence is in the normal RUN period
for at least ten seconds with the main burner fir-
ing, close the manual main fuel shutoff valve(s)
to extinguish the main burner flame.
f. The flame signal should drop below 1.25 Vdc
within .three or eight seconds after the main
flame goes out.
g. Safety shutdown will occur (depending on the
FFRT of the amplifier).
IMPORTANT
1. If the RM7888A fails to shut down on any of these
tests, take corrective action; refer to the Trouble-
shooting section and the RM7888A diagnostics
and return to the beginning of all Checkout tests.
2. When all Checkout tests are completed, reset all
switches to original states.

TROUBLESHOOTING

RM7888A System Diagnostics
Troubleshooting of control system equipment failures is
easier with the RM7888A self-diagnostics and first-out
annunciation. In addition to an isolated spst alarm relay
(audible annunciation), the RM7888A provides visual
annunciation by displaying the ALARM LED.
Self-diagnostics of the RM7888A enable it to detect and
annunciate both external and internal system problems.
External faults such as interlock failures, flame failures
and false flame signals, are annunciated by the RM7888A
lockout, which energizes the ALARM LED, by using the
optional Keyboard Display Module or 7800 SERIES
System Annunciation Diagnostics and Troubleshooting,
form 65-0118.
The RM7888A provides diagnostic information to aid the
service mechanic to obtain information when
troubleshooting the system, see Table 7 or Table 9.
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