AERCO BMK 3.0 LN Dual-Fuel Series Gas Fired Low NOx Boiler System - Manual (Page 34)

INITIAL START-UP
4-2
1/8" NPT PLUG
(INSTALL MANOMETER HERE)
LEAK DETECTION
BALL VALVE
PROPANE HIGH
GAS PRESSURE
SWITCH
NATURAL
GAS SSOV
PROPANE
SSOV
NATURAL GAS
LOW GAS
PRESSURE
SWITCH
BALL
VALVE
NAT. GAS &
PROPANE
PRESSURE
REGULATOR
FEEDBACK
LINES
NATURAL GAS
HIGH GAS
PRESSURE
SWITCH
PROPANE
INLET
NAT. GAS
INLET
PROPANE
LOW GAS
PRESSURE
SWITCH
Figure 4-1
1/8 Inch Gas Plug Location
4.2.3 Accessing the Vent Probe Port
The unit contains NPT plugs on both the left and
right side of the exhaust manifold at the rear of
the unit as shown in Figure 4-2. Prepare the port
for the combustion analyzer probe as follows:
1. Remove the plug from the probe port on the
left or right side of the exhaust manifold.
UNIT
FRAME
EXHAUST
MANIFOLD
CONDENSATE
TRAP
DRAIN
HOSE
TO FLOOR
DRAIN
FLUE
VENT PROBE
PORT
Figure 4-2
Analyzer Probe Hole Location
2. If necessary, adjust the stop on the
combustion analyzer probe so that it will
extend mid-way into the flue gas flow. DO
NOT install the probe at this time.
IMPORTANT
For Dual Fuel units, perform the natural
gas combustion calibration procedures in
para. 4.3 before performing the propane
combustion calibration procedures in
para. 4.4.
Refer to Appendix K for switchover
instructions when changing from Natural
Gas to Propane or from Propane to
Natural Gas.
4.3 NATURAL GAS COMBUSTION
CALIBRATION
The Benchmark 3.0 Dual Fuel Boiler is
combustion calibrated at the factory prior to
shipping. However, recalibration as part of initial
start-up is necessary due to changes in the local
altitude, gas BTU content, gas supply piping and
supply regulators. Factory Test Data sheets are
shipped with each unit. These sheets must be
filled out and returned to AERCO for proper
Warranty Validation.
It is important to perform the following procedure
as outlined. This will keep readjustments to a
minimum and provide optimum performance.
1. Open the water supply and return valves to
the unit and ensure that the system pumps
are running.
2. Open the natural gas supply valve(s) to the
unit.
3. Set the control panel ON/OFF switch to the
OFF position.
4. Turn on external AC power to the unit. The
display will show LOSS OF POWER and the
time and date.
5. Set the unit to the Manual Mode by pressing
the AUTO/MAN key on the control panel. A
flashing Manual Valve Position message will
be displayed with the present rate in %.
Also, the MANUAL LED will light.
6. Adjust the Air/Fuel Valve open position to
0% by pressing the ▼ arrow key.
7. Ensure that the leak detection ball valve
(Figure 4-1) downstream of the SSOV is
open.
8. Ensure that the Fuel Selector Switch (Figure
4-3 is in the NATURAL GAS position. In
addition, ensure that the Fuel Type option in
the Configuration Menu (Table 3-4) is set to
Natural Gas.