AERCO KC Series Equipped with C-More Controller for Massachusetts Only - Manual (Page 35)

INITIAL START-UP
4-5
NOTE:
Adjust the inlet air shutter only at 100% valve
position. Do not adjust the differential pressure
regulator.
25. Change the valve position to 30%. 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.
26. Continue this procedure until all oxygen
levels are within the ranges specified in
Tables 1, 2 and 3.
27. Record all readings on the AERCO start-up
sheet provided with each unit. Proceed to
paragraph 4.5.
4.4 PROPANE COMBUSTION
CALIBRATION
For propane units it will be necessary to install
an additional 8” W.C. manometer. This
manometer will be used to measure the
pressure drop across the air/propane mixing
orifice. After performing the setup procedures in
paragraphs 4,2.2 through 4.2.4, install the 8”
W.C. manometer as described in steps 1, 2 and
3 which follow.
1. Referring to Fig. 4.5, remove the 1/8” NPT
plug from the gas inlet pipe ahead of the
burner and install a 1/8” NPT barbed fitting.
2. Remove the 1/2” NPT plug from the tee
located after the air pressure regulator and
install a 1/2” barbed fitting (see fig. 4.5).
3. Attach the 8” W.C. manometer to the barbed
fittings installed in steps 1 and 2.
NOTE:
The combustion calibration data in Tables 1, 2
and 3 apply to both natural gas and propane
units. Therefore, refer to these Tables when
performing propane combustion calibration.
For propane, combustion calibration data will be
checked at 30%, 16% and 100%. Note that the
data In Table 2 is applicable to a valve position
of 16% for propane and 13% for natural gas.
4. While performing the combustion calibration
procedure in paragraph 4.3, measure the
pressure drop across the air/propane mixing
orifice using the 0-8” W.C. manometer.
5. This reading should remain a constant 3.8”
to 4” W.C. throughout the operating range.
6. If the pressure drop is not within this range,
remove the cap from the air pressure
regulator.
7. Using a flat blade screwdriver adjust the
regulator until 3.8”-4.0” W.C. is obtained.
Clockwise will increase the reading and
counter-clockwise will decrease the reading.
8. If adjustments are made to this regulator it
will be necessary to recheck oxygen settings
at 16%, 30%, and 100% valve positions.
NOTE:
After an adjustment is made to the air regulator,
the cap must be put back on securely to obtain
an accurate reading.
Figure 4.5
Propane Air Differential Pressure Taps
4.5 UNIT REASSEMBLY
Once combustion calibration is set properly, the
unit can be re-assembled for permanent
operation.
1. Set the ON/OFF switch to the OFF position.
Disconnect the AC power supply from the
unit.
2. Shut off the gas supply to the unit.
3. Remove the differential pressure regulator
cap and cap gasket (see Figure 4.3).
4. Apply a drop of silicone to the regulator
adjusting screw to lock its setting.