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Step 3:
Ignite the Burners
(Continued)
Step 4:
Set High Fire Gas
Tap B
Manometer
Step 5:
Set Low Fire Gas
Step 6:
Verify the Gas
Settings
20
8.
Initiate the ignition sequence through the flame monitoring
control system.
9.
Check that all the burners in the zone have ignited.
10.
If shut-off solenoid valves are installed at each burner, then
repeat 6 and 7 for all the burners in the zone.
11.
If all the burners have ignited, drive the zone to high fire. Verify
flame is present at each burner.
1.
Use the gas curves from the appropriate ExtensoJet datasheet
for the gas being used to find the differential gas pressure
needed at high fire. This is the target value for high fire.
2.
Connect the manometer to taps B and D (across the gas
orifice).
3.
Measure the high fire differential gas pressure for the first
burner.
Tap D
4.
Adjust the gas butterfly valve at the burner until the gas flow is
at the target value.
5.
Repeat 3 and 4 for the other burners in the zone.
6.
Check the gas pressure at the inlet to the zone ratio
regulator. This should be at least 5" w.c. (12.5 mbar) higher
than the loading line pressure. It should not exceed the
maximum pressure rating of the ratio regulator (optional).
1.
Drive the system to low fire.
2.
Measure the gas pressure drop at the first burner.
3.
Select the valve according to the control method:
a.
With high/low control:
Adjust the gas bypass butterfly valve (see ExtensoJet
Design Guide No. 230) until the minimum fire that will still
maintain a strong flame signal is obtained.
b.
With modulating gas control:
Adjust the zone gas automatic butterfly valve (see
ExtensoJet Design Guide No. 230) until the minimum fire
that will still maintain a strong flame signal is obtained.
Note:
It is very difficult to measure the very low pressures
experienced at low fire, and it may be necessary to rely
on visual inspection. This is especially true when gas
turndowns in excess of 10 to 1 are being used. The main
intent is to provide a clean stable flame with a good flame
signal that will not cause the furnace temperature to
overshoot.
Make sure that all the settings are still the same after you
have cycled the system several times between high and low
fire.
Note:
When all the settings have been completed, mark the
position of the indicator on the butterfly valves to indicate
valve position.
Eclipse ExtensoJet v2 Installation Guide No. 230, 9/17/2008
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Table of Contents
Troubleshooting
