RBI LCD Series Installation & Operation Manual page 29

Input Rate, Natural Gas
Gas appliances are rated based on sea level operation
with no adjustment required at elevations up to 5000 ft,
1524 m . At elevations above 5000 ft, 1524 m , input
ratings should be reduced by 4% for each additional
1000 ft, 305 m .
Check the input rate as follows:
1. Turn off all other gas appliances that use the
same gas meter as the boiler/water heater.
2. Call your gas supplier and ask for the heating
value of the gas.
3. Connect a flue gas analyzer to the vent pipe.
4. Start the boiler/water heater and let it run for 15
minutes.
5. Using the gas meter and a stopwatch, clock the
time that it takes to burn 10 cubic feet of gas and
divide this time by 10.
6. Insert the heating value and the time, in seconds,
into the formula below.
7. Input = (heating value, Btu/hr)(3600)/(time, seconds)
8. If the computed rate deviates by more than 5% from
the rated input value of the unit adjust the manifold
pressure accordingly. DO NOT adjust the manifold
pressure by more than 5%. If a proper rate cannot
be maintained without adjusting the manifold
pressure beyond the 5% limit, the main burner
orifices must be replaced. If the input rate is too low,
go to the next lager size of main burner orifices. If
the input rate is too high, go to the next smaller size.
9. At full input the CO2 should be between 7.5% and
8.5% with a CO reading of less than 50 ppm.
CAUTION: Never increase the input of the boiler/
water heater above that for which it is rated. Doing
so can cause premature failure of the unit!
Pilot Adjustment
The pilot burner is actually an isolated main burner that's
controlled by a separate pilot valve. Pilot pressure
settings are as shown in Table 19. These pressures are
measured at the pilot pressure valve, see Figure 19.
Tables 12 and 13 above list the firing mode that is
associated with each stage.
To view the pilot without main burner operation, take the
following steps:
For L225-L400:
1. Remove the upper front jacket panel.
2. Turn off main burner gas flow by turning the main
burner gas valve knob to the off position, Figure 18.
3. Obser ve the pilot flame through one of the
observation ports located at the left and right ends
of the unit.
LCD INSTALLATION AND OPERATION INSTRUCTIONS
For L600-L2300:
1. Remove the upper front jacket panel.
2. Turn off main burner gas flow by turning the manual
gas valve(s) in the control compartment to the off
position, see Figure 19.
3. Obser ve the pilot flame through one of the
observation ports located at the left and right ends
of the unit.
Pilot pressures will be set at the factory. However, if it
is necessary to adjust the pilot pressure to match those
in Table 19, take the following steps:
1. Remove the upper front jacket panel.
2. Remove the 1/8" plug from the pilot pressure test
port and connect a 20 in, 508 mm W.C. manometer
to it, see Figure 18.
3. Remove the gas pressure regulator cap from the
pilot valve. See Figure 18 for the location of the
regulator and cap.
4. Use a 3/32 hex wrench to turn the pressure regulator
adjustment screw clockwise to increase the pilot
pressure and counterclockwise to decrease it.
5. Replace the pressure regulator adjustment screw
cap.
Gas Pressure Adjustment
CAUTION: The maximum inlet gas pressure listed on
the rating plate must not be exceeded or damage
to the boiler/water heater may occur voiding the
warranty!
The minimum supply pressure listed on the rating plate
is for input adjustment.
NATURAL GAS: Optimum results are obtained when the
boiler/water heater is operated with the manifold
pressure(s) set per Table 19. The manifold pressure
should not vary outside these ranges. Each gas valve
pressure regulator has been preset at the factory. If
adjustment is necessary the following steps must be
followed:
1. Remove the 1/8" plug from the manifold pressure
tap valve. Connect 20 in, 508 mm WC mano-meters
to it, see Figure 19.
2. Remove the regulator adjustment screw cap from
the main gas valve.
3. Rotate the regulator adjustment screw clockwise to
increase the manifold pressure, counter clock-wise
to decrease it.
4. Replace the regulator adjustment screw cap and
manual shut off valve pressure tap plug.
CAUTION: Never force the regulator adjustment
screw beyond the stop limits or damage to the
regulator will occur!
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