Low-Fire Adjustment (250 And 350 Mbh Two Staged Only) - Trane IntelliPak 3 with Symbio 800 Installation, Operation And Maintenance Manual

Startup the Unit
If adjustment is needed, adjust the regulator on the
valve. Refer to Figure 38, p. 67
250 & 350 MBh two stage, and
stage valve on all other multi-stage and modulating
burners, for the adjustment screw location. Turn the
screw clockwise to increase the gas pressure or
counterclockwise to decrease the gas pressure.
Combustion Air Analysis
1. Using a flue analyzer make note of the oxygen, carbon
dioxide, and the Air Free CO levels. Take several
samples to assure an accurate reading.
Important: The flue reading should be taken from
center of flue and at least 4 inches down
from the outlet.
2. Compare the measured oxygen level to the combustion
curve in Figure 36, p. 66. The oxygen content of the
flue gas should be 4% to 5%. If the oxygen level is
outside this range, contact the Technical Support for
assistance.
Figure 36. Natural gas combustion curve (ratio of oxygen to carbon dioxide in percent)
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0 1 2 3 4 5
66
for two stage valve on
Figure 37, p. 67 for one
Curve
A =
A
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
Percent Oxygen
Low-Fire Adjustment (250 and 350 MBH
Two Staged only)
1. Use the TEST initiation procedures outlined in the
previous section to operate the furnace in the low-fire
state (1st Stage).
2. Check the manifold gas pressure of the valve by using
the pressure port on the manifold section downstream
of the valve. The manifold pressure for Low Fire First
Stage should be set to 1.2" w.c. (3.0" w.c. for propane).
If adjustment is needed, adjust the LO regulator on the
two stage valve. Refer to
adjustment screw location. Turn the screw clockwise to
increase the gas pressure or counterclockwise to
decrease the gas pressure.
3. Check the oxygen, carbon dioxide, and the Air Free CO
levels after each adjustment.
4. Tap the STOP button on the User Interface to stop the
system operation.
Fuel
1,000 BTU per cu ft.
of Natural Gas
Figure 38, p. 67 for the
RT-SVX080A-EN