Benchmark 750-3000 Installation & Startup Manual
SECTION 4
– INITIAL START-UP
OMM-115_D
•
GF-200
•
5/9/2019
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4.4.2 PROPANE GAS COMBUSTION CALIBRATION
PROPANE Combustion Calibration Instructions
These instructions apply only to units running
PROPANE
gas. Instructions for doing
combustion calibration on a unit running Natural Gas appear in the previous section, 4.4.1.
1.
Open the water supply and return valves to the unit and ensure that the system pumps are
running.
2.
Open the
PROPANE
supply valve to the unit.
3.
Set the C-
More Controller’s ON/OFF switch to the
OFF
position
4.
Turn on external AC power to the unit. The display will show a description of the unit and
then the time and date.
5.
Press the
MENU
key on the front panel of the C-More Controller and access the
Setup
menu, enter the password
6817
and then press the
ENTER
key.
6.
Set the unit to the
MANUAL
mode by pressing the
AUTO/MAN
key. A flashing
Manual
Valve Position
message will be displayed with the present position in %
and the
MANUAL
LED will light.
7.
Adjust the air/fuel valve position to
0%
by pressing the
▼ arrow key and then press
ENTER
.
8.
Ensure that the leak detection ball valve downstream of the SSOV is open and the
manometer is attached and functioning properly.
9.
Set
the
ON/OFF
switch
to
the
ON
position
.
10.
Press the
MENU
key on the front panel of the C-More Controller until
COMBUSTION CAL
MENU
appears on the display.
11.
Press the Up ▲ arrow key until
SET
Stdby V Out (Standby Voltage)
setting appears.
Verify that it is set to
2.0 V
(the default). AERCO recommends it be kept at 2.0 volts to
prevent flue gas recirculation. Individually vented units in positive pressure boiler rooms
may set
SET
Stdby V Out
to
0
volts.
12.
Press the Down ▼ arrow key until
SET Valve Position
appears, then press
CHANGE
.
13.
Use the Up ▲ arrow key to change the valve position to
30
%. The unit should begin its
start sequence and fire.
14.
Next, verify that the gas pressure downstream of the SSOV is set to the value in Table 4-4
for the model you are calibrating. If gas pressure adjustment is required, remove the brass
hex nut on the SSOV actuator to access the gas pressure adjustment screw (Figure 4-3).
Make gas pressure adjustments using a flat-tip screwdriver to obtain a gas pressure
approximately shown in Table 4-4.
TABLE 4-4: PROPANE Gas Pressure Range @ 100% Fire Rate
Model
Nominal Gas Pressure
BMK 750P
3.9” W.C. ± 0.2” W.C. (0.97 kPa ± 0.05 kPa)
BMK 1000P
7.6” W.C. ± 0.2” W.C. (1.89 kPa ± 0.05 kPa)
1500DF & 1500P
1.4” W.C. ± 0.1” W.C. (0.35 kPa ± 0.02 kPa)
2000DF & 2000P
2.5” W.C. ± 0.1” W.C. (0.62 kPa ± 0.02 kPa)
2500DF & 2500P
2.0” W.C. ± 0.1” W.C. (0.50 kPa ± 0.02 kPa)
3000DF & 3000P
1.6” W.C. ± 0.1” W.C. (0.40 kPa ± 0.02 kPa)
15.
On Benchmark 3000 units
only
, once the manifold gas pressure is within the range in
table 4-1, record this value; it will be used later, in Section 5.2.2:
Low Pressure Gas Test
,
and Section 5.3.2:
High Pressure Gas Test
.
