Lennox RGEN17 User manual

E2009 Lennox Industries Inc.
Dallas, Texas 75379-9900
This manual provides installation instructions for
models RGEN12 and RGEN17/18 generator sets.
Refer to XP-6515, Operation Manual, for generator set
operation and maintenance instructions.
The generator set is approved for use in stationary
standby applications in locations served by a reliable
utility power source. Do not install this generator set
indoors.
Have a Lennox dealer who is approved to sell and install
Lennox generator sets (hereinafter referred to as a
Lennox dealer) install the generator set outdoors
according to the instructions in this manual. The
generator set installation must comply with the National
Electrical Code (NEC) and local code requirements. If
the generator set is installed in Canada, the installation
must comply with the Canadian Electrical Code (CEC)
and all applicable local codes.
Information in this publication represents data available
at the time of print. The manufacturer reserves the right
to change this publication and the products represented
without notice and without any obligation or liability
whatsoever.
Read this manual and carefully follow all procedures
and safety precautions to ensure proper equipment
operation and to avoid bodily injury. Read and follow the
Safety Precautions and Instructions section.
506087-01
INSTALLATION
INSTRUCTIONS
RGEN12, RGEN17/18
RESIDENTIAL GENERATOR SET
XP-6514 4/09c
Table of Contents
Product Identification Information 2...............
Safety Precautions and Instructions 3.............
Introduction 7...................................
Section 1 Installation 9...........................
1.1 General 9.................................
1.2 Lifting 9...................................
1.3 Generator Set Inspection 9..................
1.4 Location and Mounting 9....................
1.4.1 Exhaust Requirements 14.................
1.4.2 Air Requirements 14......................
1.5 Power Supply 14............................
1.6 Fuel Requirements 15.......................
1.6.1 Fuel Supply 15...........................
1.6.2 Fuel Pipe Size 16.........................
1.7 Fuel Conversion 16.........................
1.7.1 Fuel Conversion, RGEN12 17..............
1.7.2 Fuel Conversion, RGEN17/18 18...........
1.8 Electrical Connections 19....................
1.8.1 AC Connections 20.......................
1.8.2 Remote Start Connection 20...............
1.8.3 Grounding 20............................
1.8.4 Battery Charger 20........................
1.9 Battery 21..................................
1.10 Accessories 22.............................
1.10.1 Carburetor Heater 22......................
1.11 Prestart Installation Check 24.................
1.12 Startup Notification 24.......................
1.13 Controller Configuration 24...................
1.14 Voltage and Frequency Adjustments 27........
1.14.1 Voltage Adjustment 27....................
1.14.2 Frequency Adjustment 28..................
Section 2 Wiring Diagrams 32.....................
RETAIN THESE INSTRUCTIONS
FOR FUTURE REFERENCE
Shipping and Packing List
1 -- Generator Set
Check equipment for shipping damage. If you find any
damage, immediately contact the last carrier.

Engine exhaust from this product contains chemicals
known to the State of California to cause cancer, birth
defects, or other reproductive harm.
WARNING
California Proposition 65
Product Identification Information
Generator Set Identification Numbers
Record the product identification numbers from the
generator set nameplate(s).
Model Designation
Specification Number
Serial Number
Accessory Number Accessory Description
Engine Identification
Record the product identification information from the
engine nameplate.
Manufacturer
Model Designation
Serial Number
Controller Identification
Record the controller description from the generator set
operation manual, spec sheet, or sales invoice.
Controller Description

XP-6514 4/09 3Safety Precautions and Instructions
Safety Precautions and Instructions
IMPORTANT SAFETY INSTRUCTIONS.
Electromechanical equipment,
including generator sets, transfer
switches, switchgear, and accessories,
can cause bodily harm and pose
life-threatening danger when
improperly installed, operated, or
maintained. To prevent accidents be
aware of potential dangers and act
safely. Read and follow all safety
precautions and instructions. SAVE
THESE INSTRUCTIONS.
This manual has several types of safety
precautions and instructions: Danger,
Warning, Caution, and Notice.
DANGER
Danger indicates the presence of a
hazard that will cause severe
personal injury, death,orsubstantial
property damage.
WARNING
Warning indicates the presence of a
hazard that can cause severe
personal injury, death, or substantial
property damage.
CAUTION
Caution indicates the presence of a
hazard that will or can cause minor
personal injury or property damage.
NOTICE
Notice communicates installation,
operation, or maintenance information
that is safety related but not hazard
related.
Safety decals affixed to the equipment
in prominent places alert the operator
or service technician to potential
hazards and explain how to act safely.
The decals are shown throughout this
publication to improve operator
recognition. Replace missing or
damaged decals.
Accidental Starting
Accidental starting.
Can cause severe injury or death.
Disconnect the battery cables before
working on the generator set.
Remove the negative (--) lead first
when disconnecting the battery.
Reconnect the negative (--) lead last
when reconnecting the battery.
WARNING
Disabling the generator set.
Accidental starting can cause
severe injury or death. Before
working on the generator set or
connected equipment, disable the
generator set as follows: (1) Move the
generator set master switch to the OFF
position. (2) Disconnect the power to
the battery charger. (3) Remove the
battery cables, negative (--) lead first.
Reconnect the negative (--) lead last
when reconnecting the battery. Follow
these precautions to prevent starting of
the generator set by an automatic
transfer switch, remote start/stop
switch, or engine start command from a
remote computer.
Battery
Sulfuric acid in batteries.
Can cause severe injury or death.
Wear protective goggles and
clothing. Battery acid may cause
blindness and burn skin.
WARNING
Explosion.
Can cause severe injury or death.
Relays in the battery charger
cause arcs or sparks.
Locate the battery in a well-ventilated
area. Isolate the battery charger from
explosive fumes.
WARNING
Battery electrolyte is a diluted
sulfuric acid. Battery acid can cause
severe injury or death. Battery acid
can cause blindness and burn skin.
Always wear splashproof safety
goggles, rubber gloves, and boots
when servicing the battery. Do not
open a sealed battery or mutilate the
battery case. If battery acid splashes in
the eyes or on the skin, immediately
flush the affected area for 15 minutes
with large quantities of clean water.
Seek immediate medical aid in the case
of eye contact. Never add acid to a
battery after placing the battery in
service, as this may result in hazardous
spattering of battery acid.
Battery acid cleanup. Battery acid
can cause severe injury or death.
Battery acid is electrically conductive
and corrosive. Add 500 g (1 lb.) of
bicarbonate of soda (baking soda) to a
containerwith4L(1gal.)ofwaterand
mix the neutralizing solution. Pour the
neutralizing solution on the spilled
battery acid and continue to add the
neutralizing solution to the spilled
battery acid until all evidence of a
chemical reaction (foaming) has
ceased. Flush the resulting liquid with
water and dry the area.

XP-6514 4/094 Safety Precautions and Instructions
Battery gases. Explosion can cause
severe injury or death. Battery gases
can cause an explosion. Do not smoke
or permit flames or sparks to occur near
a battery at any time, particularly when
it is charging. Do not dispose of a
battery in a fire. To prevent burns and
sparks that could cause an explosion,
avoid touching the battery terminals
with tools or other metal objects.
Remove all jewelry before servicing the
equipment. Discharge static electricity
from your body before touching
batteries by first touching a grounded
metal surface away from the battery. To
avoid sparks, do not disturb the battery
charger connections while the battery
is charging. Always turn the battery
charger off before disconnecting the
battery connections. Ventilate the
compartments containing batteries to
prevent accumulation of explosive
gases.
Battery short circuits. Explosion
can cause severe injury or death.
Short circuits can cause bodily injury
and/or equipment damage.
Disconnect the battery before
generator set installation or
maintenance. Remove all jewelry
before servicing the equipment. Use
tools with insulated handles. Remove
the negative (--) lead first when
disconnecting the battery. Reconnect
the negative (--) lead last when
reconnecting the battery. Never
connect the negative (--) battery cable
to the positive (+) connection terminal
of the starter solenoid. Do not test the
battery condition by shorting the
terminals together.
Engine Backfire/Flash
Fire
Fire.
Can cause severe injury or death.
Do not smoke or permit flames or
sparks near fuels or the fuel system.
WARNING
Servicing the air cleaner. A sudden
backfire can cause severe injury or
death. Do not operate the generator
set with the air cleaner removed.
Servicing the fuel system. A flash
fire can cause severe injury or death.
Do not smoke or permit flames or
sparks near the carburetor, fuel line,
fuel filter, fuel pump, or other potential
sources of spilled fuels or fuel vapors.
Catch fuels in an approved container
when removing the fuel line or
carburetor.
Combustible materials. A fire can
cause severe injury or death.
Generator set engine fuels and fuel
vapors are flammable and explosive.
Handle these materials carefully to
minimize the risk of fire or explosion.
Equip the compartment or nearby area
with a fully charged fire extinguisher.
Select a fire extinguisher rated ABC or
BC for electrical fires or as
recommended by the local fire code or
an authorized agency. Train all
personnel on fire extinguisher
operation and fire prevention
procedures.
Exhaust System
Carbon monoxide.
Can cause severe nausea,
fainting, or death.
The exhaust system must be
leakproof and routinely inspected.
WARNING
Generator set operation. Carbon
monoxide can cause severe nausea,
fainting, or death. Carbon monoxide
is an odorless, colorless, tasteless,
nonirritating gas that can cause death if
inhaled for even a short time. Avoid
breathing exhaust fumes when working
on or near the generator set. Never
operate the generator set inside a
building. Never operate the generator
set where exhaust gas could seep
inside or be drawn into a potentially
occupied building through windows, air
intake vents, or other openings.
Carbon monoxide symptoms.
Carbon monoxide can cause severe
nausea, fainting, or death. Carbon
monoxide is a poisonous gas present in
exhaust gases. Carbon monoxide is an
odorless, colorless, tasteless,
nonirritating gas that can cause death if
inhaled for even a short time. Carbon
monoxide poisoning symptoms include
but are not limited to the following:
DLight-headedness, dizziness
DPhysical fatigue, weakness in
joints and muscles
DSleepiness, mental fatigue,
inability to concentrate
or speak clearly, blurred vision
DStomachache, vomiting, nausea
If experiencing any of these symptoms
and carbon monoxide poisoning is
possible, seek fresh air immediately
and remain active. Do not sit, lie down,
or fall asleep. Alert others to the
possibility of carbon monoxide
poisoning. Seek medical attention if
the condition of affected persons does
not improve within minutes of breathing
fresh air.
Fuel System
Explosive fuel vapors.
Can cause severe injury or death.
Use extreme care when handling,
storing, and using fuels.
WARNING
Gas fuel leaks. Explosive fuel
vapors can cause severe injury or
death. Fuel leakage can cause an
explosion. Check the LP vapor gas or
natural gas fuel system for leakage by
using a soap and water solution with
the fuel system test pressurized to
6--8 ounces per square inch
(10--14 inches water column). Do not
use a soap solution containing either
ammonia or chlorine because both
prevent bubble formation. A successful
test depends on the ability of the
solution to bubble.

XP-6514 4/09 5Safety Precautions and Instructions
Hazardous Noise
Hazardous noise.
Can cause hearing loss.
Never operate the generator set
without a muffler or with a faulty
exhaust system.
CAUTION
Engine noise. Hazardous noise can
cause hearing loss. Generator sets
not equipped with sound enclosures
can produce noise levels greater than
105 dBA. Prolonged exposure to noise
levels greater than 85 dBA can cause
permanent hearing loss. Wear hearing
protection when near an operating
generator set.
Hazardous Voltage/
Moving Parts
Hazardous voltage.
Can cause severe injury or death.
Operate the generator set only when
all guards and electrical enclosures
areinplace.
Moving parts.
WARNING
Hazardous voltage.
Backfeed to the utility system can
cause property damage, severe
injury, or death.
If the generator set is used for
standby power, install an automatic
transfer switch to prevent inadvertent
interconnection of standby and
normal sources of supply.
WARNING
Welding the generator set.
Can cause severe electrical
equipment damage.
Never weld components of the
generator set without first
disconnecting the battery, controller
wiring harness, and engine electronic
control module (ECM).
CAUTION
Grounding electrical equipment.
Hazardous voltage can cause
severe injury or death. Electrocution
is possible whenever electricity is
present. Ensure you comply with all
applicable codes and standards.
Electrically ground the generator set,
transfer switch, and related equipment
and electrical circuits. Turn off the main
circuit breakers of all power sources
before servicing the equipment. Never
contact electrical leads or appliances
when standing in water or on wet
ground because these conditions
increase the risk of electrocution.
Welding on the generator set. Can
cause severe electrical equipment
damage. Before welding on the
generator set perform the following
steps: (1) Remove the battery cables,
negative (--) lead first. (2) Disconnect
all engine electronic control module
(ECM) connectors. (3) Disconnect all
generator set controller and voltage
regulator circuit board connectors.
(4) Disconnect the engine battery-
charging alternator connections.
(5) Attach the weld ground connection
close to the weld location.
Connecting the battery and the
battery charger. Hazardous voltage
can cause severe injury or death.
Reconnect the battery correctly,
positive to positive and negative to
negative, to avoid electrical shock and
damage to the battery charger and
battery(ies). Have a qualified
electrician install the battery(ies).
Short circuits. Hazardous
voltage/current can cause severe
injury or death. Short circuits can
cause bodily injury and/or equipment
damage.Do not contact electrical
connections with tools or jewelry while
making adjustments or repairs.
Remove all jewelry before servicing the
equipment.
Electrical backfeed to the utility.
Hazardous backfeed voltage can
cause severe injury or death. Install
a transfer switch in standby power
installations to prevent the connection
of standby and other sources of power.
Electrical backfeed into a utility
electrical system can cause severe
injury or death to utility personnel
working on power lines.
Airborne particles.
Can cause severe injury or
blindness.
Wear protective goggles and clothing
when using power tools, hand tools,
or compressed air.
WARNING
Heavy Equipment
Unbalanced weight.
Improper lifting can cause severe
injury or death and equipment
damage.
Do not use lifting eyes.
Lift the generator set using lifting bars
inserted through the lifting holes on
the skid.
WARNING

XP-6514 4/096 Safety Precautions and Instructions
Hot Parts
Hot engine and exhaust system.
Can cause severe injury or death.
Do not work on the generator set until
it cools.
WARNING
Servicing the exhaust system. Hot
parts can cause severe injury or
death. Do not touch hot engine parts.
The engine and exhaust system
components become extremely hot
during operation.
Servicing the engine heater. Hot
parts can cause minor personal
injury or property damage. Install the
heater before connecting it to power.
Operating the heater before installation
can cause burns and component
damage. Disconnect power to the
heater and allow it to cool before
servicing the heater or nearby parts.
Notice
NOTICE
Canadian installations only.For
standby service connect the output of
the generator set to a suitably rated
transfer switch in accordance with
Canadian Electrical Code, Part 1.

XP-6514 4/09 7
Introduction
See Figure 1 and Figure 2 for generator set component
locations.
ADV-7466-
1. Muffler
2. Oil check
3. Oil fill
4. Air cleaner
5. Controller user interface
6. Generator set master switch (RUN-OFF/RESET-AUTO)
7. Load circuit breaker
8. Fuses
9. RS-232 connector (for application program updates)
10. Field-connection terminal block location
11. Spark plug locations (both sides)
12. Oil drain hose
13. Oil drain valve
14. Oil filter
15. Exhaust
16. Equipment ground
17. Battery charger
18. DSAI lead location
19. Fuel block
20. Gas regulator assembly
21. Fuel solenoid valve
22. Fuel inlet
23. Air intake
24. Engine starting battery location (battery purchased separately)
7
6
5
8
9
Control detail
See control detail
1234
14 13
24
7
6
16
17 20
21
22
23
15
11
10
18 19
12
Figure 1 Generator Set Component Locations, RGEN12

XP-6514 4/098
12 5420
16
6
3
13 25
17
19
1415
22
ADV-7341A-B
10
26
24
9
21
27
29
Control detail 8
11
7
12
1. Muffler
2. Oil check
3. Oil fill
4. Air cleaner
5. Spark plug locations (both sides)
6. Oil filter
7. Oil cooler location
8. Controller user interface
9. Generator set master switch (RUN-OFF/RESET-AUTO)
10. Line circuit breaker
11. Fuses
12. RS-232 connector (for application program updates)
13. Engine starting battery location (battery purchased separately)
14. Oil drain hose
15. Nameplate location (on base)
16. Oil drain valve
17. Exhaust
18. Carburetor heater access opening
19. LP fuel orifice location (inside hose fitting)
20. Gas regulator assembly
21. DSAI leads
22. Fuel solenoid valve
23. Fuel inlet
24. Air intake
25. Battery cables
26. Battery charger
27. Field-connection terminal block location
28. 120 VAC receptacles for battery charger and optional
carburetor heater
29. Field connections inside junction box if optional terminal
block is not used
See control detail 18
28
23
Figure 2 Generator Set Component Locations, RGEN17/18

XP-6514 4/09 9Section 1 Installation
Section 1 Installation
1.1 General
Have a Lennox dealer install the generator set outdoors
according to the instructions in this manual. Do not
install this generator set indoors.
Use the specifications provided here only in the initial
planning. Use the generator set and transfer switch
dimension drawings and wiring diagrams for installation.
1.2 Lifting
Unbalanced weight.
Improper lifting can cause severe
injury or death and equipment
damage.
Do not use lifting eyes.
Lift the generator set using lifting bars
inserted through the lifting holes on
the skid.
WARNING
Model Weight, kg (lb.)
RGEN12 186 (410)
RGEN17/18 227 (500)
Figure 1-1 Approximate Weights
Approximate generator set weights are shown in
Figure 1-1. Use lifting bars inserted through the holes in
the skid to lift the unit. See Figure 1-2 or Figure 1-4 for
lifting hole locations.
1.3 Generator Set Inspection
Complete a thorough inspection of the generator set.
Check for the following:
1. Inspect the generator set for loose or damaged
parts or wires. Repair or tighten any loose parts
before installation.
2. Check the engine oil. Fill, if necessary, with the
recommended viscosity and grade of oil. Use
synthetic oil, API (American Petroleum Institute)
Service Class SG or higher. See XP-6515,
Operation Manual, for additional information.
1.4 Location and Mounting
See Figure 1-2 or Figure 1-4 for the generator set
dimensions and fuel and electric inlet locations. The
drawing dimensions are shown in millimeters, with
inches in brackets.
Install the generator set outdoors. Provide the minimum
clearance around the generator set shown in Figure 1-3
or Figure 1-5. Locate the generator set so that the hot
exhaust does not blow on plants or other combustible
materials. Do not install the generator set where
exhaust gas could accumulate and seep inside or be
drawn into a potentially occupied building.
The generator set is shipped on a plastic mounting pad.
Prepare a flat, level mounting area covered with a weed
barrier and gravel as shown in Figure 1-3 or Figure 1-5.
Set the plastic mounting pad directly on the gravel. Do
not install the mounting pad directly on grass.

XP-6514 4/0910 Section 1 Installation
Figure 1-2 Generator Set Mounting Details and Dimensions, RGEN12, ADV-7466A-

XP-6514 4/09 11Section 1 Installation
Figure 1-3 Generator Set Clearances, RGEN12, ADV-7466B-

XP-6514 4/0912 Section 1 Installation
Figure 1-4 Generator Set Mounting Details and Dimensions, RGEN17/18, ADV-7341A-B

XP-6514 4/09 13Section 1 Installation
Figure 1-5 Generator Set Clearances, RGEN17/18, ADV-7341B-B

XP-6514 4/0914 Section 1 Installation
1.4.1 Exhaust Requirements
Carbon monoxide.
Can cause severe nausea,
fainting, or death.
The exhaust system must be
leakproof and routinely inspected.
WARNING
Generator set operation. Carbon monoxide can cause
severe nausea, fainting, or death. Carbon monoxide is an
odorless, colorless, tasteless, nonirritating gas that can cause
death if inhaled for even a short time. Avoid breathing exhaust
fumes when working on or near the generator set. Never
operate the generator set inside a building. Never operate the
generator set where exhaust gas could seep inside or be
drawn into a potentially occupied buildingthrough windows, air
intake vents, or other openings.
The exhaust system is complete for generator sets
installed outdoors. Do not install this generator set
indoors.
Figure 1-6 gives the exhaust flow and temperature at
rated load. The engine exhaust mixes with the
generator set cooling air at the exhaust end of the
enclosure. Mount the generator set so that the hot
exhaust does not blow on plants or other combustible
materials. Maintain the clearances shown in Figure 1-3
or Figure 1-5.
Exhaust System 60 Hz
Exhaust flow at rated kW, m3/min. (cfm)
RGEN12 3.8 (135)
RGEN17/18 5.3 (187)
Exhaust gas exiting the enclosure at rated kW,
_C(_F) 216 (420)
Figure 1-6 Exhaust Flow and Temperature
1.4.2 Air Requirements
The generator set requires correct air flow for cooling
and combustion. The inlet and outlet openings in the
sound enclosure provide the cooling and combustion
air. Figure 1-7 shows the locations of the cooling air
intake and exhaust vents. Inspect the air inlet and outlet
openings inside and outside the housing to ensure that
the air flow is not blocked.
tp6195
2
1. Exhaust outlet
2. Alternator air intake (both sides)
3. Engine air intake
3
1
3
Figure 1-7 Cooling Air Intake and Exhaust, Typical
Air Requirements, m3/min. (cfm)
Model Hz
Cooling
Air
Combustion
Air
Total
Inlet Air
RGEN12 60 26.9 (950) 1.1 (39.2) 28.0 (990)
RGEN17/
18 60 28.0 (989) 1.62 (57.3) 29.6 (1045)
Figure 1-8 Air Requirements
1.5 Power Supply
Power must be supplied from a source that is GFCI
protected to the generator set location for the battery
charger and the optional carburetor heater. Connect
power from a circuit on the essential loads panel to the
120-VAC receptacles. Figure 1-9 lists the power
requirements for the battery charger and accessories.
Equipment
Power Requirement, Max.
Watts Amps Volts
Battery charger 192 1.6
120
Optional carburetor heater:
RGEN12
RGEN17/18
38
40
0.32
0.34
Figure 1-9 Power Requirements

XP-6514 4/09 15Section 1 Installation
1.6 Fuel Requirements
The generator set operates using natural gas or LP
vapor fuel. The generator set is EPA-certified for both
natural gas and LP vapor fuels.
The fuel system installation must comply with the NEC
and local codes.
1.6.1 Fuel Supply
Because of variable climates and geographical
considerations, contact the local fuel supplier for fuel
system planning and installation. Figure 1-10 lists the
recommended fuel ratings and other fuel supply
information for natural gas and LP vapor fuels.
Fuel type
Natural
Gas
LP
Vapor
Fuel supply inlet 1/2 NPT
Fuel supply pressure, kPa (in. H2O)
RGEN12
1.3--2.7
(5--11)
1.7--2.7
(7--11)
Fuel supply pressure, kPa (in. H2O),
RGEN17/18
1.7--2.7
(7--11)
Fuel flow rate, Btu/hr.
RGEN12 193000 203000
RGEN17/18 242000 280000
Nominal Fuel Rating, Btu/ft.3
Natural gas 1000
LP vapor 2500
Figure 1-10 Fuel Supply
Verify that the output pressure from the primary gas
utility (or LP tank) pressure regulator is 1.7--2.7 kPa
(7--11 in. water column) and that the utility gas meter
flow rate is sufficient to supply the generator set at rated
load plus all other gas-consuming appliances. See
Figure 1-11 or Figure 1-12 for fuel consumption.
Contact the fuel supplier for flow rate information or a
gas meter upgrade.
Figure 1-2 or Figure 1-4 shows the location of the fuel
inlet connection. Use flexible sections to prevent fuel
line breakage caused by vibration. Hold the fuel
solenoid valve with a wrench when tightening the fuel
connections. Protect all fuel lines from machinery or
equipment contact, adverse weather conditions, and
environmental damage.
Fuel Consumption, at % load m3/hr. (cfh) 60 Hz
Natural Gas, m3/hr. (cfh)
100% 5.9 (209)
75% 4.8 (168)
50% 3.6 (127)
25% 2.4 (85)
LP Vapor, m3/hr. (cfh)
100% 3.1 (108)
75% 2.5 (87)
50% 1.9 (65)
25% 1.2 (44)
LP vapor conversion factors:
8.58 ft.3=1lb.
0.535 m3=1kg
36.39 ft.3= 1 gal.
Nominal fuel rating:
Natural gas: 37 MJ/m3(1000 Btu/ft.3)
LP vapor: 93 MJ/m3(2500 Btu/ft.3)
Figure 1-11 Fuel Consumption, RGEN12
Fuel Consumption, at % load m3/hr. (cfh) 60 Hz
Natural Gas, m3/hr. (cfh)
100% 6.9 (242)
75% 5.8 (204)
50% 4.4 (155)
25% 3.4 (120)
LP Vapor, m3/hr. (cfh)
100% 3.2 (112)
75% 2.7 (96)
50% 2.1 (74)
25% 1.6 (57)
LP vapor conversion factors:
8.58 ft.3=1lb.
0.535 m3=1kg
36.39 ft.3= 1 gal.
Nominal fuel rating:
Natural gas: 37 MJ/m3(1000 Btu/ft.3)
LP vapor: 93 MJ/m3(2500 Btu/ft.3)
Figure 1-12 Fuel Consumption, RGEN17/18
1.6.2 Fuel Pipe Size
Ensure that the natural gas pipe size and length meet
the specifications in Figure 1-13 or Figure 1-14.

XP-6514 4/0916 Section 1 Installation
Measure the pipe length from the primary gas pressure
regulator to the pipe connection on the generator set
fuel inlet. Add 2.4 m (8 ft.) to the measured length for
each 90 degree elbow. Compare the total pipe length
with the chart in Figure 1-13 or Figure 1-14 to find
required pipe size.
Contact local LP provider for LP installation information.
Pipe Size Maximum Pipe Length, m (ft.)
3/4 in. NPT 9.2 (30)
1in.NPT 30 (100)
1 1/4 in. NPT 68.6 (225)
Figure 1-13 Fuel Pipe Size, Natural Gas, RGEN12
Minimum Gas Pipe Size Recommendation, in. NPT
Pipe Length, m (ft.)
Natural Gas
(242,000 Btu/hr.)
LP Vapor
(280,000 Btu/hr.)
8 (25) 13/4
15 (50) 1 1
30 (100) 11/4 1
46 (150) 11/4 11/4
61 (200) 11/4 11/4
Figure 1-14 Fuel Pipe Size, RGEN17/18
1.7 Fuel Conversion
The multi-fuel system allows conversion from natural
gas to LP vapor (or vice-versa) in the field while
maintaining emissions-standard compliance. A trained
technician or a Lennox dealer can convert the fuel
system.
Accidental starting.
Can cause severe injury or death.
Disconnect the battery cables before
working on the generator set.
Remove the negative (--) lead first
when disconnecting the battery.
Reconnect the negative (--) lead last
when reconnecting the battery.
WARNING
Disabling the generator set. Accidental starting can
cause severe injury or death. Before working on the
generator set or connected equipment, disable the generator
set as follows: (1) Move the generator set master switch to the
OFF position. (2) Disconnect the power to the battery charger.
(3) Remove the battery cables, negative (--) lead first.
Reconnect the negative (--) lead last when reconnecting the
battery. Follow these precautions to prevent starting of the
generator set by an automatic transfer switch, remote
start/stop switch, or engine start command from a remote
computer.
Explosive fuel vapors.
Can cause severe injury or death.
Use extreme care when handling,
storing, and using fuels.
WARNING

XP-6514 4/09 17Section 1 Installation
1.7.1 Fuel Conversion, RGEN12
Two fuel connections on the fuel block allow field-
conversion between natural gas and LP vapor. The fuel
metering valves are factory-set and sealed to comply
with applicable emission standards and to provide the
best possible hot and cold starting.
Note: Do not adjust the factory-sealed fuel-metering
adjustments on the fuel block. Changing the fuel-
metering adjustments may violate federal or state
laws.
Use the following procedure to convert from natural gas
(NG) to LP vapor, moving the fuel connection from the
natural gas to the LP port, plugging the natural gas port,
and connecting the leads to the digital spark advance
ignition (DSAI). See Figure 1-15 for the fuel system
component locations.
2
GM29253
1. DSAI connector location
2. Fuel block
3. Fuel inlet, 1/2 in. NPT female
3
1
Figure 1-15 Fuel System Locations, RGEN12
Procedure to convert from NG to LP, RGEN12
1. Place the generator set master switch in the OFF
position.
2. Disconnect the power to the battery charger.
3. Disconnect the generator set engine starting
battery, negative (--) lead first.
4. Turn off the fuel supply.
5. Remove the hose clamp and fuel hose from the
hose fitting in the fuel block. See Figure 1-16.
5
tp6195
1. Fuel block
2. Fuel metering valves—factory-sealed, do not adjust
3. Fuel inlet, 1/2 in. NPT
4. Hose fitting
5. Plug
1
2
3
4
Natural gas
setup shown
Figure 1-16 Fuel Block, RGEN12
6. Remove the hose fitting from the natural gas outlet
port in the fuel block. See Figure 1-16.
7. Remove the plug from the LP port in the fuel block.
See Figure 1-16. Clean the plug with a dry cloth or
brush, apply fresh pipe sealant, and install the plug
into the natural gas outlet port.
8. Clean the hose fitting with a dry cloth or brush,
apply fresh pipe sealant to the threads, and install
the fitting into the LP port.
Note: Do not adjust the fuel metering valves.
9. Slide the hose onto the hose fitting and secure it
with the clamp.
10. For the RGEN12: Disconnect the DSAI leads for
LP; connect the DSAI leads for natural gas. See
Figure 1-17 and Figure 1-18.
Fuel DSAI Leads
Natural Gas Connect
LP Disconnect
Figure 1-17 DSAI Connection,12/17/18 kW Models

XP-6514 4/0918 Section 1 Installation
1
tp6195
1. DSAI leads (12 kW model only)
Figure 1-18 Digital Spark Advance Module Leads
(located in generator set air intake area)
11. Connect and turn on the new fuel supply.
12. Check that the generator set master switch is in the
OFF position.
13. Reconnect the generator set engine starting
battery leads, negative (--) lead last.
14. Reconnect power to the battery charger.
15. Start the generator set by moving the generator set
master switch to the RUN position.
16. Check for leaks using a gas leak detector.
17. Run the generator set and check the operation.
Use the controller to adjust the output and stability if
necessary. See Section 1.14 for instructions.
18. Move the generator set master switch to the OFF/
RESET position to shut down the generator set.
To convert from LP vapor to natural gas, follow the same
fuel conversion procedure, moving the hose fitting to the
natural gas port and plugging the LP port. For the
RGEN12 model, disconnect the DSAI leads for LP
vapor. See Figure 1-17 and Figure 1-18.
1.7.2 Fuel Conversion, RGEN17/18
For LP vapor fuel, an orifice is used in the fuel line. The
unit is typically shipped set up for natural gas, with the
loose orifice tied near the fuel line. To convert to LP
vapor, install the orifice and disconnect the spark
advance leads as described below. See Figure 1-19 for
the fuel system component locations.
1. Hose fitting (LP orifice fits inside; see Figure 1-20)
2. Regulator
3. Fuel valve
4. Fuel inlet, 1/2 in. NPT female
5. Fuel hose with clamp
6. DSAI connector location (see Figure 1-21)
1
GM51561A-D
4
6
52
3
2
3
Fuel System Detail
4
Figure 1-19 Fuel System Components, RGEN17/18
Procedure to Convert from NG to LP, RGEN17/18
1. Place the generator set master switch in the OFF
position.
2. Disconnect the power to the battery charger.
3. Disconnect the generator set engine starting
battery, negative (--) lead first.
4. Turn off the fuel supply.
5. Remove the hose clamp and fuel hose from the
hose fitting. See Figure 1-19.

XP-6514 4/09 19Section 1 Installation
6. Place the orifice into hose fitting. See Figure 1-20.
7. Slide the hose onto the hose fitting and secure it
with the clamp.
1. LP orifice (remove for natural gas)
2. Hose fitting
3. Regulator
12
3
tp6514
Figure 1-20 LP Fuel Orifice, RGEN17/18
8. Disconnect digital spark-advance module (DSAI)
leads 65 and N5 for LP. (Connect the leads for
natural gas.) See Figure 1-21 and Figure 1-22.
tp6514
1. DSAI leads 65 and N5:
connect for natural gas, disconnect for LP.
1
Figure 1-21 Digital Spark Advance Ignition (DSAI)
Leads 65 and N5, RGEN17/18
Fuel DSAI Leads 65 and N5
Natural Gas Connect
LP Disconnect
Figure 1-22 DSAI Connections
9. Connect and turn on the new fuel supply.
10. Check that the generator set master switch is in the
OFF position.
11. Reconnect the generator set engine starting
battery leads, negative (--) lead last.
12. Reconnect power to the battery charger.
13. Start the generator set by moving the generator set
master switch to the RUN position.
14. Check for leaks using a gas leak detector.
15. Run the generator set and check the operation.
Use the controller to adjust the output and stability if
necessary. See Section 1.14 for instructions.
16. Move the generator set master switch to the OFF/
RESET position to shut down the generator set.
To convert from LP vapor to natural gas, remove the fuel
orifice and connect the DSAI leads together.
1.8 Electrical Connections
Hazardous voltage.
Backfeed to the utility system can
cause property damage, severe
injury, or death.
If the generator set is used for
standby power, install an automatic
transfer switch to prevent inadvertent
interconnection of standby and
normal sources of supply.
WARNING
Grounding electrical equipment. Hazardous voltage can
cause severe injury or death. Electrocution is possible
whenever electricity is present. Ensure you comply with all
applicable codes and standards. Electrically ground the
generator set, transfer switch, and related equipment and
electrical circuits. Turn off the main circuit breakers of all
power sources before servicing the equipment. Never contact
electrical leads or appliances when standing in water or on wet
ground because these conditions increase the risk of
electrocution.
Electrical backfeed to the utility. Hazardous backfeed
voltage can cause severe injury or death. Install a transfer
switch in standby power installations to prevent the connection
of standby and other sources of power. Electrical backfeed
into a utility electrical system can cause severe injury or death
to utility personnel working on power lines.
NOTICE
Canadian installations only. For standby service connect
the output of the generator set to a suitably rated transfer
switch in accordance with Canadian Electrical Code, Part 1.

XP-6514 4/0920 Section 1 Installation
Have a Lennox dealer or a licensed electrician make the
following electrical connections. The electrical
installation must comply with the National Electrical
Code (NEC) and all applicable local codes. Canadian
installations must comply with the Canadian Electrical
Code (CEC) and applicable local codes.
Ground the generator set from the GRD terminal inside
controller compartment according to applicable codes.
1.8.1 AC Connections
Refer to the transfer switch specifications and
Figure 1-23 for the acceptable cable sizes. Route AC
leads through flexible conduit. Ensure that the leads
and conduit do not interfere with the operation of the
generator set or obstruct the service areas.
GM54820
GM58022
Figure 1-23 Field-Connection Terminal Block
See Figure 1-23. Leads have been factory-installed
from the junction box to the terminal block for easy field
wiring. Make field connections to the other side of the
terminal block. Refer to the decal near the terminal
block for connections and cable sizes.
1. Connect the leads from the transfer switch
emergency source lugs to the L1 and L2
connections on the generator set terminal block.
2. Connect the neutral (L0) and ground (GRD) leads
from the ATS and the main panel to the
corresponding connection points on the terminal
block. See Section 1.8.3, Grounding. See
Section 1.8.2 for remote start connections.
3. The terminal block kit includes 120 VAC
receptacles for the battery charger and optional
carburetor heater. Connect utility power to the
terminal block as shown. Connect to a circuit that is
supplied by the generator set if utility power is lost.
See Section 1.5 for more information about the
120 VAC power requirement.
1.8.2 Remote Start Connection
Connect leads 3 and 4 from the controller to the
automatic transfer switch’s engine start terminals or to
an optional remote start/stop switch. Route the engine
start leads through separate conduit from the AC power
and load leads.
1.8.3 Grounding
Ground the generator set. The grounding method must
comply with NEC and local codes. Connect the
grounding strap to the generator set ground lug,
terminal GND inside the controller compartment.
Generator sets are shipped with the generator neutral
attached to the generator in the junction box. At
installation, the neutral can be grounded at the
generator set or lifted from the ground stud and isolated
if the installation requires an ungrounded neutral
connection at the generator. The generator set will
operate properly with the neutral either bonded to
ground or isolated from ground at the generator.
Various regulations and site configurations including the
National Electrical Code (NEC), local codes, and the
type of transfer switch used in the application determine
the grounding of the neutral at the generator. NEC 2002
Section 250.20 is one example that has a very good
explanation of the neutral grounding requirements for
generators.
1.8.4 Battery Charger
A 6-amp battery charger is factory-installed in the
battery compartment to keep the starting battery fully
charged. The battery charger’s DC leads are factory-
connected.
Plug the battery charger’s power cord into the
receptacle on the bottom of the controller junction box.
Refer to the generator set operation manual for battery
charger operation information.