14
32-00057—01
NOTE:
Be sure main gas manual shut off valves are
closed.
4. With pressure taps open, connect a manometer
between
Tap E
and the chamber.
5. Set system control to stay at low fire during and after
ignition sequence.
6. Attempt to ignite burner.
7. During trial for ignition, adjust bypass pressure
regulator
and adjustable limiting orifice
to achieve
the appropriate
Δ
p between
Tap E
and the chamber as
listed in the appropriate datasheet.
NOTE:
If viewing the flame, it should be blue with flashes
of yellow. The flame should be completely within the
combustion tube. When firing propane or butane, a proper
low fire flame may have sustained flashes of yellow.
8. If burner does not ignite:
a. Attempt to ignite the burner again to purge air from
the gas piping.
b. If burner still does not ignite, adjust bypass pressure
regulator
a half turn clockwise to increase gas
flow.
c. Repeat until burner ignites. If necessary, refer to
Chapter 5, “Maintenance & Troubleshooting” in this
manual.
10.After ignition, verify bypass flame:
a. Shut off gas. When chamber temperature is below
250°F (121°C), shut off combustion air blower.
b. Restart combustion air blower, drive through purge
cycle, and ignite burner.
c. Measure low fire gas pressure to the burner gas inlet
. Verify pressure at
is within the range specified
on the datasheet for your burner.
d. Verify repeatability of ignition and low fire flame
signal.
11. Close all pressure taps.
Step 4: Set Low Fire Gas
■
This procedure is written with the assumption the
burner has a flame monitoring control system
installed and operating. A proper purge cycle must
be part of the system and purge timing should not
be bypassed.
1. Set manual gas butterfly valve to 75% open. See
Figure 4.8.
Figure 4.7. Ratio Regulator Adjustment
NOTE:
To adjust manual butterfly valve:
a. Loosen set screw
b. Turn dial
c. Tighten set screw
Figure 4.8. Manual Butterfly Valve Adjustment
3. Open all manual gas shut off valves.
4. Set system control to stay at low fire during and after
ignition sequence.
5. With taps open, connect manometer between
Tap B
and the combustion chamber.
6. Ignite the burner.
WARNING
1
Bias
adjusting
screw
CCW for
more gas
Set Screw
Outer Dial
Full Open
75% Open
