Fuel/Air Adjustment - Harsco Industrial C1500H Installation & Owner's Manual

3.11 F /A A
UEL IR DJUSTMENT
®
The gas train for MACH
and a gas safety shut off control valve, combined into one valve assembly. The valves function in series with the
variable speed combustion blower to supply the correct gas air ratio for optimum firing performance and efficiency.
The combustion blower speed is controlled automatically by the boiler controller. The blower speed determines the
amount of air flow and the amount of suction/negative pressure at the gas valves. The gas valve adjusts gas flow to
maintain the proper delivery pressure at the outlet of the valve.
NOTICE: Adjustments shall only be performed by qualified and knowledgeable installer or service agency specifically
trained and certified to perform maintenance and/or startup on the Harsco Industrial, Patterson-Kelley MACH
3.11.1 Combustion setup and adjustment
Boiler Test Mode for High and Low fire:
Set the combustion using the Service Menu BNR ON TEST HI & BNR ON TEST LOW modes. These test modes
should be used when checking and setting the gas safety shut off / control valves on the MACH
a heat request is required. Once the boiler cycles on, use the arrow keys to access the Service Menu and select the
BNR ON TEST HI/LOW mode and push enter. Then select BNR ON TEST HI or the BNR ON TEST LOW mode and
push enter. The boiler will ramp to high or low fire.
NOTICE! There must be sufficient load to operate the boiler at high fire to perform the following adjustments. Start
the boiler and observe proper operating parameters for the system.
The air flow is pre-set at the factory prior to shipment. Gas flow is dependent primarily on fan speed not upstream gas
pressure. The automatic gas valve may have to be adjusted to obtain proper combustion readings for specific local
conditions. A combustion analyzer must be used. Combustion should be set in accordance with Table 3-1.
Table 3-1 Combustion Exhaust Reading For Setting Gas Safety Shut Off / Control Valves
Fuel
Natural Gas
Propane Gas
C1500H/C2000H/C2500/C3000/C4000 boilers are equipped with gas/air ratio control valve
Nominal
Gas Pressure
7" W.C
11" WC
Main gas shut off with
Service port for
checking incoming gas
pressure
High Fire Setting
% O % CO
2 2
4.8 ± 0.2 9.2 ± 0.1
4.8 ± 0.2 10.4 ± 0.3
42
®
MACH Gas Fired Boiler
®
boiler. In this mode
Low Fire Setting
% O % CO
2 2
5.0 ± 0.2 9.1 ± 0.1
5.0 ± 0.2 10.3 ± 0.3
®
boiler.