Checkout - Honeywell 7800 Series Product Data

CHECKOUT

WARNING
Do not allow fuel to accumulate in the combustion
chamber. If fuel is allowed to enter the chamber for
longer than a few seconds without igniting, an
explosive mixture could result. It is recommended that
you limit the trial for pilot to ten seconds, and limit the
attempt to light the main burner two seconds from the
time the fuel has reached the burner nozzle. In any
case, do not exceed the nominal lightoff time specified
by the equipment manufacturer. Close the manual fuel
shutoff valve(s) if the flame is not burning at the end of
the specified time.
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 removing or
installing the RM7896.
3. Make sure all manual fuel shutoff valve(s) are
closed before starting the initial lightoff check and
the Pilot Turndown tests.
4. Do not put the system in service until you have
satisfactorily completed all applicable tests in this
section and any others required by the equipment
manufacturer.
CAUTION
If an RM7896 is replaced with a lower or higher
functioning 7800 SERIES Relay Module, the burner
will not sequence unless wiring changes are made.
IMPORTANT
1. If the system fails to perform properly, refer to
7800 SERIES System Annunciation Diagnostics
and Troubleshooting, form 65-0118.
2. Repeat ALL required Checkout tests after all
adjustments are made. ALL tests must be satisfied
with the flame detector(s) in its FINAL position.
Equipment Recommended
Volt-ohmmeter (20K ohm/volt minimum sensitivity):
• 0-300 Vac capability.
• 0-6000 ohm capability.
• 0-10 Vdc capability.
Checkout Summary
• Preliminary inspection—all installations.
• Flame signal measurement—all installations.
• Initial lightoff check for proved pilot—all installations using
a pilot.
• Initial lightoff check for direct spark ignition of oil—all
burners using DSI.
• Pilot turndown test—all installations using a pilot.
• Hot refractory saturation test—all installations using
Infrared (lead sulfide) Flame Detectors.
• Hot refractory hold-in test—all installations.
7800 SERIES RM7896A,B,C,D RELAY MODULE
• Ignition interference test—all installations using flame rods.
• Ignition spark pickup—all installations using Ultraviolet
Flame Detectors.
• Response to other ultraviolet sources—all installations
using Ultraviolet Flame Detectors.
• Flame signal with hot combustion chamber—all installations.
• Safety shutdown tests—all installations.
See Fig. 1 and 2 for location of component parts and see Fig. 7
and 8 or Q7800 Specifications for terminal locations.
Preliminary Inspection
Perform the following inspections to avoid common problems.
Make certain that:
1. Wiring connections are correct and all terminal screws
are tight.
2. Flame detector(s) is clean, installed and positioned
properly. Consult the applicable Instructions.
3. Correct combination of amplifier and flame detector(s)
is used. See Table 2 in the Specifications section.
4. Plug-in amplifier and purge card are securely in place.
5. Burner is completely installed and ready to fire; consult
equipment manufacturer instructions. Fuel lines are
purged of air.
6. Combustion chamber and flues are clear of fuel and
fuel vapor.
7. Power is connected to the system disconnect switch
(master switch).
8. Lockout switch is reset (push in reset pushbutton) only
if the RM7896 is powered, see Fig. 1 and 2.
9. Run/Test Switch is in RUN position (RM7896C,D).
10. System is in the STANDBY condition. POWER LED is
energized.
11. All limits and interlocks are reset.
Flame Signal Measurement (Fig. 20 and
Table 5)
Measure the flame signal at the appropriate times defined in
the following checkout tests. Read the flame signal volts dc at
the flame amplifier test jacks + and - (Com).
1. Use a 20K ohm/volt meter with a 0 to 10 Vdc capability.
2. Set the 20K ohm/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. 20.
4. Allow a few seconds for the meter reading to stabilize.
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 5 after
all tests are completed and all adjustments are 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 5 (L1) and
L2 (N). Make sure the master switch is closed,
connections are correct, and the power supply is of the
correct voltage and frequency and is sinusoidal.
2. Check the detector wiring for defects including:
• Incorrect connections.
• Wrong type of wire.
• Deteriorated wire.
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65-0193