AERCO KC1000 Boiler equipped with C-More 2002 - Manual (Page 49)

INITIAL START-UP
4-3
NOTE:
On initial start-up, or return to service from a
fault condition, the unit will remain at a 29% firing
rate for two-minutes, although the control signal
may indicate a greater input.
9. Following the warm-up period, increase the
firing rate in 20% increments while monitor-
ing the gas pressure after every increase. If
gas pressure dips below 8.5” W.C. for FM
gas trains and 8.9” for IRI gas trains at any
input percentage, stop and raise the
pressure. Once 100% is reached, adjust the
gas pressure for 8.5” W.C. or 8.9” W.C.
NOTE:
If 8.5” W.C. for FM gas trains or 8.9” W.C. for IRI
gas trains cannot be obtained at the 100% firing
rate, it will be necessary to stop calibration and
contact the local AERCO representative in your
area. Running the unit on insufficient gas
pressure will void the warranty
10. Once 8.5” W.C. or 8.9” W.C. is set at the
100% level, change the firing rate to 30%
and insert the combustion analyzer probe
into the stack.
NOTE:
Always go to a percentage of firing rate from the
same direction, (i.e., 100% to 30% or 30% to
20%). Whenever going to a firing rate from
below (i.e., 20% to 30%), first go above then
back down to the desired firing rate. This is
necessary due to hysteresis in the air/fuel
stepper motor. Hysteresis causes the air/fuel
valve to stop in a slightly different position if the
firing rate percentage is approached from below
or above. This results in a difference in oxygen
readings for the same firing rate percentage
causing unnecessary recalibration.
11. Allow enough time for the combustion
analyzer to settle. Compare the measured
oxygen level to the oxygen range for the
existing intake air temperature in Table 1.
12. If the measured oxygen level is within the
range listed in Table 1, no adjustment is
necessary. Proceed to step 19.
13. If the measured oxygen level is not within
the range listed in Table 1, remove the
regulator cap and cap gasket from the
differential pressure regulator (see
Figure 4.3) and proceed to step 14.
Table 1
Combustion Oxygen Levels for a 30%
Firing Rate
Inlet Air
Temp
Oxygen
(+0.2/-1.0)
Carbon
Monoxide
-20°F 7.5 % <50 ppm
0°F 7.3 % <50 ppm
10°F 7.2 % <50 ppm
30°F 6.8 % <50 ppm
50°F 6.4 % <50 ppm
60°F 6.2 % <50 ppm
70°F 6.0 % <50 ppm
80°F 5.8 % <50 ppm
90°F 5.6 % <50 ppm
100°F 5.4 % <50 ppm
DIFFERENTIAL
PRESSURE
REGULATOR
REGULATOR CAP
CAP GASKET
Figure 4.3
Differential Regulator
14. Use a flat-tip screwdriver to adjust the
differential pressure regulator. Turn the
screwdriver:
• counterclockwise to increase the
oxygen level
• clockwise to decrease the oxygen level
15. Replace the regulator cap and cap gasket
and wait for the analyzer reading to settle.
16. When the analyzer reading settles, compare
the new oxygen reading to Table 1.
17. If necessary, repeat the adjustment until the
oxygen level is within the range specified in
Table 1.
18. Replace the regulator cap and cap gasket.