Harsco Industrial MACH C-750GG Operating instructions

©2010 Harsco Industrial, Patterson-Kelley
Printed: 5/26/2011
MACH®GAS-FIRED BOILER
C-750GG / C-900GG / C-1050GG
DUAL FUEL BOILER GUIDE
Natural Gas or Propane
This manual is to be used in conjunction
with the MACH®Installation & Owner’s
Manual (latest edition).
Model #: ___________________
Serial #: ___________________
Start-Up Date: ____________________
Harsco Industrial, Patterson-Kelley
100 Burson Street,
East Stroudsburg, PA 18301
Telephone: [phone]
Facsimile: [phone]
www.harscopk.com
OW
MACH® Dual Fuel
Rev 1.10 (11/22/10)
C.S.A Design-Certified
Complies with ANSI Z21.13/CSA 4.9
Gas-Fired Low Pressure Steam and Hot Water
Boilers
ASME Code, Section IV
Certified by Harsco Industrial, Patterson-Kelley
C.S.A Design-Certified
Complies with ANSI Z21.13/CSA 4.9
Gas-Fired Low Pressure Steam and Hot Water
Boilers

MACH®Gas-Fired Boiler
Dual Fuel (NG & LP) MACH Boiler Supplement
2

MACH®Gas-Fired Boiler
Dual Fuel (NG & LP) MACH Boiler Supplement
3
1.0Dual Fuel MACH® Boilers 4
2.0MACH®C-750GG / C-900GG / C-1050GG DUAL FUEL BOILERS...................... 4
2.1Gas Input Connections..........................................................................................................4
2.2Fuel Selection........................................................................................................................6
2.3Gas Valve Adjustment...........................................................................................................6
2.4Maintenance..........................................................................................................................7
2.5Troubleshooting.....................................................................................................................8
2.6Assembly Drawing MACH®C-750GG / C-900GG / C-1050GG..........................................9
2.7Electrical Logic Drawing MACH®C-750GG / C-900GG / C-1050GG................................10
2.8Electrical Layout Drawing MACH®C-750GG / C-900GG / C-1050GG..............................11
3.0LIMITED WARRANTY ......................................................................................... 12
NOTICE! The information contained in this document is subject to change without notice from Harsco
Industrial, Patterson-Kelley.
It is essential to read, understand and follow the recommendations of the
manual before installing, operating or servicing this equipment. Failure to do so could result in fire or
explosion and serious injury, death and/or property damage.

MACH®Gas-Fired Boiler
Dual Fuel (NG & LP) MACH Boiler Supplement
4
1.0 Dual Fuel MACH® Boilers
This manual describes the installation requirements of the Harsco Industrial, Patterson-Kelley MACH® dual fuel
boilers. While details may differ slightly, basic operation is the same for all models. This boiler is built to operate with
natural gas (NG) or propane (LP).
This boiler has been constructed by the factory and shipped as a dual fuel boiler. It is essential to read, understand,
and follow the recommendations of this manual before installing, operating, or servicing this equipment. Failure to do
so could result in serious injury, death, and/or property damage.
Each MACH® dual fuel boiler is equipped with two current switches: one switch is in the natural gas valve circuit and
the other is in the propane gas valve circuit. These switches are wired in such a manner as to prevent both fuels from
being fired at the same time. In the unlikely event that both fuel valves are open at the same time, the current
switches cause a high gas pressure error which will shut both gas valves and force a manual reset lock-out of the
ENVI™ control.
2.0 MACH®C-750GG / C-900GG / C-1050GG DUAL FUEL BOILERS
2.1 GAS INPUT CONNECTIONS
The MACH®dual fuel boiler is equipped with dedicated connections for each fuel. The natural gas (NG) connection is
a 1 1/4” ball valve. The propane (LP) connection is a 1” ball valve. If a fuel connection is not used, it must be capped.
It is imperative that the natural gas line be connected to the 1 1/4” connection
and the propane line be connected to the 1“ connection. Incorrect gas connections could result in
serious injury, death and/or property damage.
Do not exceed maximum pressure limits (14” W.C.) for LP & NG fuels.
Installation of the fuel lines must comply with all applicable codes. It is the responsibility of the installer to ensure
compliance with all the requirements of the authority having jurisdiction.
The fuel line ball valves are located on the rear face of the boiler. Each line is labeled for the required fuel. Attach the
propane (LP) line to the 1” ball valve labeled “PROPANE”. Attach the natural gas (NG) line to the 1 1/4” ball valve
labeled “NATURAL GAS”.
It is recommended to close the ball valve for the non-selected fuel.
Use approved pipe sealer that resists the action of fuel gases such as natural gas or propane.
DO NOT USE Teflon™ tape.
Reorder No. 6020-V2WHPK
Improper use may
result in fire or injury.
Read instructions/safety
manual before installing,
operating or servicing boiler.
c
!
WARNING
1998 HCS, Inc. 800-748-0241

MACH®Gas-Fired Boiler
Dual Fuel (NG & LP) MACH Boiler Supplement
5
GAS INPUT CONNECTIONS
←PROPANE
(
1”
)
←NATURAL GAS
(
1 ¼”
)

MACH®Gas-Fired Boiler
Dual Fuel (NG & LP) MACH Boiler Supplement
6
2.2 FUEL SELECTION
1. Before switching fuels, ensure that the boiler is turned off.
2. Ensure that both fuel lines are correctly connected to the boiler.
3. Make sure the ball valve for the desired fuel is open.
4. Use the fuel selector switch, located inside the left control panel door near the top of the boiler, to select the
desired fuel. The fuel selector switch has three positions: propane, off and natural gas.
NOTICE! The dual fuel selector switch is a hesitation type switch. When switching fuels you must
release the switch in the “OFF” position before switching to the other fuel.
5. Start the boiler according to the MACH® C750-C1050 Installation & Owner’s Manual (latest edition)
NOTICE! It is recommended to close the ball valve of the non-selected fuel.
FUEL SELECTOR SWITCH
2.3 GAS VALVE ADJUSTMENT
Open front door on the right side of the boiler. The two gas valves are located inside the cabinet on the left. Each
valve is labeled and adjusted for a specific fuel. The upper gas valve is for natural gas (NG). The lower gas valve is
for propane (LP). Check the combustion using a combustion analyzer and adjust the fuel/air ratio of the valve being
used according to the procedures outlined in the latest edition of the MACH® C750-C1050 Installation & Owner’s
Manual.

MACH®Gas-Fired Boiler
Dual Fuel (NG & LP) MACH Boiler Supplement
7
2.4 MAINTENANCE
The required maintenance on these units is as described in the latest edition of the MACH® C750-C1050 Installation
and Owner’s Manual.
Service and Maintenance on these units must only be performed by
knowledgeable and experienced personnel familiar with its operation. Incorrect or improper servicing of
these units could result in severe injury, death and/or property damage.
GAS VALVES
←NATURAL GAS
(
NG
)
←PROPANE
(
LP
)

MACH®Gas-Fired Boiler
Dual Fuel (NG & LP) MACH Boiler Supplement
8
2.5 TROUBLESHOOTING
If LOCKING HIGH GAS PRESSURE is shown on the display of the ENVI™ control, the burner operation is
interrupted, and the boiler locks out. The high gas pressure switch opens when there is excessive manifold gas
pressure for the proper operation of the boiler.
In addition, a high gas pressure error could be due to both gas valves being open. There are LED indicators on each
gas valve that illuminate when they are powered. If you observe that both gas valves are powered simultaneously,
you will get a LOCKING HIGH GAS PRESSURE error as described above. If this error is observed, call a qualified
service technician for assistance.

MACH®Gas-Fired Boiler
Dual Fuel (NG & LP) MACH Boiler Supplement
9
2.6 ASSEMBLY DRAWING MACH®C-750GG /C-900GG /C-1050GG
Mark Description
1 Burner Transition Piece
2 Blower
3 Venturi
4 Pilot Gas Tube (LP or NG)
5 High Gas Pressure Switch (LP and/or NG)
6 NG Pilot Gas Tube
7 NG Automatic Gas Valve
8 NG Low Gas Pressure Switch
9 LP Pilot Gas Tube
10 LP Automatic Gas Valve
11 LP Low Gas Pressure Switch

MACH®Gas-Fired Boiler
Dual Fuel (NG & LP) MACH Boiler Supplement
10
2.7 ELECTRICAL LOGIC DRAWING MACH®C-750GG /C-900GG /C-1050GG

MACH®Gas-Fired Boiler
Dual Fuel (NG & LP) MACH Boiler Supplement
11
2.8 ELECTRICAL LAYOUT DRAWING MACH®C-750GG /C-900GG /C-1050GG

MACH®Gas-Fired Boiler
Dual Fuel (NG & LP) MACH Boiler Supplement
12
3.0 LIMITED WARRANTY
Warranty information may by found in the latest edition of the MACH® Installation and Owner’s Manual for
each unit series.