CleaverBrooks FLX Operation, Service And Parts Manual page 38

Chapter 2
ON-OFF BURNER ADJUSTMENTS
Refer to the burner data plate located inside the control panel
door. The data plate will list the burner information: burner
and control voltage, phase, cycle, motor amperage, maximum
and minimum fuel input settings, manifold pressure (at zero
furnace pressure). Add the furnace pressure to get the correct
manifold pressure at maximum firing rate.
These procedures assume that the pre-startup tasks, check
list, electrical interference test, and pilot turndown tests have
been performed in accordance with the instructions in this
manual.
Allow the boiler to fully warm up before making adjustments
for most efficient combustion. Refer to the boiler instruction
manual for the boiler controls settings.
GAS BURNERS
On-Off gas burners are typically equipped with a pressure
regulator, and a solenoid operated diaphragm gas valve to
control the on-off operation of the burner. Adjustments are
made by matching the correct fuel/air ratios.
1. Open the manual gas shutoff cocks.
2. Check the gas pressure at the inlet of the regulator and
the pressure downstream of the regulator. Make sure
they are in accordance with the regulator specifications.
The gas pressure required at the manifold is the pressure
that is required to fire the burner at its rated capacity. To
adjust the regulator, unscrew the cap located on top and
turn the adjustment screw clockwise to increase pres-
sure, or counterclockwise to decrease pressure.
:
Notice
MAXIMUM VALVE INLET PRESSURE
FOR THE V4944 IS 0.5 PSI. IF LINE PRESSURE IS
GREATER, AN OVER PRESSURE DEVICE IS TO
BE INSTALLED DOWNSTREAM OF MAIN GAS
REGULATOR (CSD-1-CF160).
3. Turn the burner switch to the "On" position.
4. Adjust the burner for a smooth ignition of the main
flame. The bleed valve adjustment controls the opening
of the V48 valve. When the controller is not calling for
heat, the coil is de-energized. The plunger in the 3-way
actuator is in the "Down" position so the bleed port is
closed and the supply port is open. Gas flows into the
top part of the valve. The gas pressure on top of the dia-
phragm, the weight, and the spring hold the valve
closed. On call for heat, the controller contacts close and
the coil is energized. This pulls the plunger to the "Up"
position, opening the bleed port and closing the supply
port. The gas in the top of the valve flows out through
the bleed port. This reduces the pressure on top of the
diaphragm, allowing the gas pressure below to lift the
2-26
diaphragm and open the valve.
5. Adjust the high-fire gas input to match maximum rating.
Adjust the gas regulator so the manifold pressure
matches the rating on the burner data plate. Verify and
record the readings and pressures. High-fire is typically
3.0% to 4.0% O with a target value of less than 50 ppm
2
CO.
The burner should be adjusted to provide correct fuel flow at
a constant rate, as indicated on the burner data plate. This is
achieved by clocking the gas flow at the gas meter. The gas
utility or gas meter calibration data, should be consulted to
determine the correction factors to be applied to the meter.
Natural Gas Input Calculation Using a Meter
HHV = higher heating value of gas, Btu/ft
available, use 1000)
CF = cubic feet of gas clocked
t = gas meter clock time, seconds
Pm = meter upstream pressure (see Pref for units)
Pb = barometric pressure (see Pref for units)
Pref = 14.696 psi, or 29.92 "HG, or 406.77" W.C.
Tref = gas reference temperature, ºF (use 77 if data
unavailable)
Tg = gas temperature at meter, ºF
6. After completing all adjustments, replace the regulator
gaskets and slotted aluminum screw cap. Tighten all
linkages and marked settings. Complete the startup
report at the end of this section.
OIL BURNERS
On-Off burners use the Suntec B2TC-8931 oil pump model.
High-fire pressure adjustment is 200-300 PSI (solenoid
energized), and low-fire pressure adjustment is 100-200 PSI
(solenoid de-energized).
1. Briefly push in the starter contact and release to ensure
that the blower motor and oil pump are rotating in the
correct direction.
2. Turn the burner switch to the "On" position.
3. Make sure a pressure gauge, 0-600 PSI range, is
installed, downstream of the solenoid valves. Adjust the
burner for a smooth ignition of the main flame. Discon-
nect the wiring to the solenoid on the Suntec B2TC-
8931 oil pump. Loosen and remove knurled nut on the
solenoid. Adjust the screw, clockwise to increase low-
fire oil pressure, and counterclockwise to decrease the
low-fire oil pressure, until a smooth ignition of the oil
Profire V Burner
3
(if no data is
750-177