Honeywell 7800 Series Manual page 42

RM7888A
CHECKOUT
reached, close all manual fuel shutoff valve(s), or open the
electrical circuits of all automatic fuel valve(s). Visually
observe when the burner flame or FLAME LED goes out. If
this takes more than three seconds, the infrared detector is
sensing hot refractory. Immediately terminate the firing
cycle. (Lower the set point to the operating controller, or set
the Fuel Selector Switch to OFF. Do not open the master
switch.)
NOTE: Some burners continue to purge oil lines between
the valve(s) and nozzle(s) even though the fuel valve(s)
is closed. Terminating the firing cycle (instead of open-
ing the master switch) will allow purging the combus-
tion chamber. This will reduce a buildup of fuel vapors
in the combustion chamber caused by oil line purging.
If the detector is sensing hot refractory, the condition
must be corrected. Add an orifice plate in front of the cell to
restrict the viewing area of the detector. If this does not
correct the problem, resight the detector at a cooler, more
distant part of the combustion chamber. While re-sighting
the detector, be aware that it must also properly sight the
flame. For an infrared detector, try lengthening the sight
pipe or decreasing the pipe size (diameter). For details,
refer to the detector Instructions and the equipment Operat-
ing Manual. Continue adjustments until hot refractory hold-
in is eliminated.
ULTRAVIOLET SENSOR, IGNITION
SPARK RESPONSE TEST
(ALL ULTRAVIOLET DETECTORS)
Test to make certain that the ignition spark is not actuat-
ing the FLAME LED:
1. Close the pilot and main burner manual fuel shutoff
valve(s).
2. Start the burner and energize Special Function 1
(terminal 6) only to stop the sequence in the PILOT IGN
period. Ignition spark should occur, but the flame signal
should not be more than 0.5 Vdc.
3. If the flame signal is higher than 0.5 Vdc and the
FLAME LED does come on, consult the equipment operat-
ing manual and resight the detector farther out from the
spark, or away from possible reflection. It may be neces-
sary to construct a barrier to block the ignition spark from
the detector view. Continue adjustments until the flame
signal due to ignition spark is less than 0.5 Vdc.
NOTE: The Honeywell Q624A Solid State Spark Genera-
tor will prevent detection of ignition spark when prop-
erly applied with the C7027, C7035 or C7044 Minipeeper
Ultraviolet Flame Detectors. The Q624A is only for use
with gas pilots.
65-0175
RESPONSE TO OTHER ULTRAVIOLET SOURCES
Some sources of artificial light, such as incandescent or
fluorescent bulbs, mercury, sodium vapor lamps and day-
light, produce small amounts of ultraviolet radiation. Under
certain conditions, an ultraviolet detector will respond to
these sources as if it is sensing a flame. To 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 cham-
ber 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 voltage
level to be at least 1.25 Vdc for 40 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).
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