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Operation
5. Measure the gas pressure at the manual gas valve. The inlet gas pressure should not exceed
6. Open the first manual gas valve in the burner vestibule.
7. Open the manual gas valve in the pilot gas line and bleed the air from the line.
8. Remove any debris from combustion air inlets and/or hoods. Note that some combustion air
Pre-Purge and Pilot Ignition (3:1, 10:1 Turndown, 200-2000 MBh)
Move the manual disconnect switch in the heater vestibule to the ON position. The system should
energize, and the combustion blower motor should start, indicating that all of the safety/limit
contacts are closed:
•
•
•
•
The combustion airflow switch (CAFS1) should close, starting the purge timer, the green power
light should illuminate on the flame-relay panel, the combustion air dampers should open and the
prepurge cycle should begin. The combustion air blower should run for approximately 90 seconds
to evacuate the heat exchanger of any combustible gases before the ignition sequence. This
prepurge cycle is initiated before every startup.
With the prepurge cycle complete, the ignition transformer and pilot solenoid should be energized,
allowing gas to flow to the pilot burner. The pilot should light immediately. The pilot flame gas
pressure should be 2.5 to 3 inches wg.
If the pilot does not light within 10 seconds, the flame relay should shut down the system, and the
red Flame Failure light should illuminate on the flame relay panel. If the pilot does not light, press
the Reset button to clear the fault and repeat the procedure outlined in
The pilot flame can be viewed through the small sight glass on the burner.
Cycle the pilot on and off several times to ensure its reliability. Turn the manual disconnect switch
in the control panel to the Off position.
Main Burner Ignition (3:1, 10:1 Turndown, 200-2000 MBh)
1. With the manual disconnect switch in the Off position, open the second manual gas valve
2. Turn the manual disconnect switch to the On position. After the pre-purge and pilot cycle, the
3. The amber Main Flame light should illuminate on the flame-relay panel after the ultra-violet
4. Check the flame-signal strength from the ultra-violet sensor. A 0 to 15 Vdc, 10K ohm (minimum)
5. Insert the positive probe of the voltmeter into the positive (+) flame-signal test point on the
6. Connect the negative probe to the negative (-) test point on the flame relay cover.
7. Allow the burner to ramp up to full fire.
28
14 inches wg. Adjust the gas pressure, if necessary.
inlets are located on the floor panel of the piping vestibule. Insure the openings are not blocked.
HLI1: high-temperature limit
AI1: airflow interlock
HPGS1: high-pressure gas switch
LPGS1: low-pressure gas switch
located downstream of the automatic gas valve/regulator in the piping vestibule. Note that this
valve is just upstream of the modulating gas valve.
main gas valve will energize and the main burner will light.
flame sensor has detected the main flame. The flame can be observed through the larger sight
glass under the burner. Normal flame color is blue; abnormal color is yellow, indicating a need
for adjustments by a qualified technician. Note that smaller sized heaters have the sight glass
on the side opposite the piping connection side.
voltmeter is required.
flame relay cover.
the desired signal strengths.
"Startup" on page
27.
Table 9
shows
CLCH-SVX08A-EN
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