Watts AERCO Benchmark 2.0LN, Operating & Maintenance Instructions

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INITIAL START-UP
4-5
Table 3 - Combustion Oxygen Levels for
100% Firing Rate
OPEN
BLOWER AIR
DUCT TO AIR
/FUEL VALVE
CLOCKWISE
OUTLET
USE A 1/2" WRENCH TO
INCREASE/DECREASE
AIR INTAKE
Figure 4.5
Iris Air Damper Locatio n
24. Change the firing rate to 40%. Allow time for
the combustion analyzer to settle. Check the
measured oxygen reading to insure that it is
still within the range as per Table 1.
25. Continue this procedure until oxygen levels
at 40%, 16% and 100% firing rates are
within the ranges specified in Tables 1, 2
and 3.
4.4 UNIT REASSEMBLY
Once combustion calibration is set properly, the
unit can be re-assembled for permanent
operation. Proceed as follows:
1. Put the green ON/OFF switch in the off
position. Disconnect the AC power supply to
the unit.
2. Shut off the gas supply to the unit.
3. Reinstall the brass hex nut back on the
regulator.
4. Remove all of the manometers and barbed
fittings and reinstall the pipe plugs using a
suitable thread compound.
5. Remove the combustion analyzer probe
from the tapped hole in the exhaust
manifold. Replace the NPT plug previously
removed in para. 4.2.3, step 1.
6. Replace the unit’s panels.
4.5 OVER-TEMPERATURE LIMIT
SWITCH
The over-temperature limit switches are located
on the plate to the left of the boiler shell. One is
a fixed manual reset switch that will shutdown
and lock out the boiler if the water temperature
reaches 210°F. The other is an adjustable auto
reset which allows the boiler to restart, once the
temperature drops below its temperature setting.
Figure 4.6 shows the location of the over
temperature limit switch.
OVER TEMP SWITCH-AUTO RESET
OVER TEMP SWITCH-MANUAL RESET
Figure 4.6
Over Temperature Limit Switch Location
Temp (ºF)
O2 CO
NOx (corrected to
3% O
2
)
130
4.3 <100ppm <40ppm
120 4.5 <100ppm <40ppm
110 4.7 <100ppm <35ppm
100 4.8 <100ppm <30ppm
90 5.0 <100ppm <30ppm
80 5.1 <100ppm <30ppm
70 5.1 <100ppm <30ppm
60 5.2 <100ppm <30ppm
50 5.3 <100ppm <30ppm
40 5.4 <100ppm <30ppm
30 5.4 <100ppm <30ppm
20 5.4 <100ppm <30ppm
10 5.4 <100ppm <30ppm
0 5.4 <100ppm <30ppm
-10 5.4 <100ppm <30ppm
-20 5.4 <100ppm <30ppm
-30 5.4 <100ppm <30ppm
-40 5.4 <100ppm <30ppm
100% Fire Rate