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according to the type of system (limiting potentiometer or
matching gas).
r. Re-adjust the midfire points for the correct O2 levels.
The linkage may need to be readjusted to obtain the correct
relationship between the fuel valve and air damper. See
Figure I-1.
s. If equipped with FGR, adjust the NOx levels at low and
midfire rates to be about 10% under the guaranteed levels
or as required for the gas firing.
t. The burner should be operating at low fire to adjust the
air proving switch. Turn the adjusting screw cw (in) until the
burner trips out (shutdown caused by the air flow switch).
Turn the adjustment screw ccw (out) 1 ½ turns from the
point of shutdown. Check the operation at higher rates.
FIGURE I-4
Typical Atomizing Air Pressure
% Rate
20
30
40
50
100
13. Heavy Oil Setup
CAUTION
WHEN WORKING WITH HEATED OIL, PROTEC-
TIVE CLOTHING, INCLUDING GLOVES, SHOULD BE
WORN TO PROTECT FROM BURNS.
The air atomized heavy oil system requires the additional
adjustment of oil temperature in the burner setup. The tem-
perature is adjusted to improve the viscosity for good atomi-
zation. Typically, this will be about 150
o
for #5 oil and 200
F for # 6 oil.
a. Prior to startup, the oil system must be operating with the
oil temperature to the burner (before the trim heater) within
o
20
F of the final temperature.
b. Place the burner switch in the "OFF" position. If this is a
combination fuel burner, make sure the fuel selector switch
is on "OIL" and that the oil pump is running.
c. Place the "Auto-Manual" switch in the manual position.
d. Place the manual flame control potentiometer in the MIN
(low fire) position.
e. Turn the electrical power on for the burner, boiler and
related components.
f. The oil may take some time to get up to temperature. If
the oil is cool, the ball valve downstream of the N.O. oil re-
turn valve (Figure B-7) can be opened to make it easier for
the oil to circulate and reach operating temperature.
g. Verify that the oil metering valve is at the nearly closed
position.
h. Turn the burner switch to "ON". This will start the blower
motor and initiate the prepurge cycle.
JB Manual
Minimum
10 - 25
12 - 30
15 - 35
20 - 40
25 - 60
o
o
F for #4 oil, 180
DO NOT ATTEMPT TO START THE BURNER WHEN
EXCESS OIL HAS ACCUMULATED, WHEN THE
UNIT IS FULL OF VAPOR, OR WHEN THE COM-
BUSTION CHAMBER IS HOT.
i. When the prepurge sequence is complete and the low
fire start switch is made, the pilot valve will open and
the pilot flame should be visible through the burner sight
port.
j. When the pilot flame is established, the flame safe-
guard will energize the main oil valves (indicated with
the Fuel Valve Light), and the burner should ignite at low
fire. This operation of the main fuel valves must be visu-
ally checked by observing the valve stem moving up with
a motorized valve or hearing the clicking noise from a
solenoid valve.
k. After a few seconds, the combustion analyzer should
have an accurate reading of the O2 in the stack. The O2
level should be between 4% and 7% (See Figure I-3 for
O2 rates) and the nozzle oil press should be between 10
and 20 PSIG. Do not attempt to fine tune combustion
until the high fire input has been set.
• Turning the cam screw in will add fuel, making it richer
and reducing the O2 level.
• Turning the cam screw out will reduce the fuel input,
increasing the O2 level.
• The air damper should be positioned for the correct low
fire settings.
• The atomizing air pressure can be adjusted using the
air bleed valve (Figure I-4).
• The oil temperature can be adjusted to obtain the best
atomization.
l. Operate the burner until the boiler is warmed up and
near the operating pressure or temperature.
m. Increase the firing rate, using the manual potentiom-
eter, while monitoring and adjusting the O2 level. Adjust
the cam, oil and atomizing air pressure and oil tempera-
F
ture as needed to reach the high fire input.
n. At high fire (end of the modulating motor travel), ad-
just the high fire input to match the maximum input listed
on the rating label. Using a flow meter, the fuel input may
be measured using the following equation,
Oil GPH = [Gal end – Gal start] x [3600 sec/hr]
/ [measured sec]
Where Gal end = meter gallons at end of test
Gal start = gallons at start of the test
Measured sec = measured time of test
GPH = Gallons per hour
o. Modulate the burner to low fire, adjusting the O2 level
as the burner modulates.
p. Readjust the low fire input, using the fuel cam and air
damper adjustments.
q. Re-adjust the midfire points for the correct O2 levels.
The linkage may need to be readjusted to obtain the cor-
rect relationship between the fuel valve and air damper.
(Figure I-1)
r. The burner should be operating at low fire to adjust
Page 39
WARNING
Startup and Operating Adjustments
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