Generac Power Systems Liquid Cooled Prepackaged Standby Generators 004721 0 004722 004723 004724 004725 1 0E1151RevM

004721-0, 004722-0, 004723-0, 004724-0, 004725-0, 004725-1, 004725-2, 004725-3, 004726-0 to the manual a79844cc-4c63-4c92-beef-bd7bf28dcced

2015-02-09

: Generac-Power-Systems Generac-Power-Systems-Liquid-Cooled-Prepackaged-Standby-Generators-004721-0-004722-0-004723-0-004724-0-004725-0-004725-1-004725- generac-power-systems-liquid-cooled-prepackaged-standby-generators-004721-0-004722-0-004723-0-004724-0-004725-0-004725-1-004725-2-004725-3-004726-0-users-manual-559958 generac-power-systems pdf

Open the PDF directly: View PDF .
Page Count: 52

Download
Open PDF In Browser	View PDF

Owner’s Manual
Liquid-cooled, Prepackaged
Standby Generators
Model Numbers
004721-0, 004722-0,
004723-0, 004724-0,
004725-0, 004725-1,
004725-2, 004725-3,
004726-0

! Not intended for use in critical life support applications. !

ONLY QUALIFIED ELECTRICIANS OR CONTRACTORS SHOULD ATTEMPT
INSTALLATION!!
DEADLY EXHAUST FUMES. OUTDOOR INSTALLATION ONLY!
This manual should remain with the unit.

INTRODUCTION
Thank you for purchasing this model of the standby
generator set product line by Generac Power Systems.
Every effort was expended to make sure that the
information and instructions in this manual are both
accurate and current at the time the manual was written. However, the manufacturer reserves the right to
change, alter or otherwise improve this product(s) at
any time without prior notice.

READ THIS MANUAL THOROUGHLY
If any portion of this manual is not understood, contact the nearest Generac Authorized Service Dealer
for starting, operating and servicing procedures.
Throughout this publication, and on tags and
decals affixed to the generator, DANGER, WARNING,
CAUTION and NOTE blocks are used to alert personnel to special instructions about a particular service or
operation that may be hazardous if performed incorrectly or carelessly. Observe them carefully. Their definitions are as follows:

DANGER

The operator is responsible for proper and safe use
of the equipment. Generac strongly recommends that
the operator read this Owner's Manual and thoroughly understand all instructions before using this
equipment. Generac also strongly recommends
instructing other users to properly start and operate
the unit. This prepares them if they need to operate
the equipment in an emergency.

OPERATION AND MAINTENANCE
It is the operator's responsibility to perform all safety
checks, to make sure that all maintenance for safe
operation is performed promptly, and to have the
equipment checked periodically by a Generac
Authorized Service Dealer. Normal maintenance service and replacement of parts are the responsibility of
the owner/operator and, as such, are not considered
defects in materials or workmanship within the terms
of the warranty. Individual operating habits and usage
contribute to the need for maintenance service.
Proper maintenance and care of the generator ensure
a minimum number of problems and keep operating
expenses at a minimum. See a Generac Authorized
Service Dealer for service aids and accessories.

After this heading, read instructions that, if not
strictly complied with, will result in personal injury
or property damage.

Operating instructions presented in this manual
assume that the standby electric system has been
installed by a Generac Authorized Service Dealer or
other competent, qualified contractor. Installation of
this equipment is not a “do-it-yourself” project.

After this heading, read instructions that, if not
strictly complied with, may result in personal injury
or property damage.

HOW TO OBTAIN SERVICE

After this heading, read instructions that, if not
strictly complied with, could result in damage to
equipment and/or property.
NOTE:
After this heading, read explanatory statements
that require special emphasis.

When the generator requires servicing or repairs,
contact a Generac Authorized Service Dealer for
assistance. Service technicians are factory-trained
and are capable of handling all of servicing needs.
When contacting a Generac Authorized Service
Dealer about parts and service, always supply the
complete model number of the unit as given on the
front cover of this manual or on the DATA LABEL
affixed to the unit.

These safety warnings cannot eliminate the hazards
that they indicate. Common sense and strict compliance with the special instructions while performing the
service are essential to preventing accidents.
Four commonly used safety symbols accompany the
DANGER, WARNING and CAUTION blocks. The type
of information each indicates is as follows:

This symbol points out important safety information that, if not followed, could endanger personal
safety and/or property of others.
This symbol points out potential explosion hazard.
This symbol points out potential fire hazard.
This symbol points out potential electrical shock
hazard.

AUTHORIZED SERVICE
DEALER LOCATION
To locate the nearest GENERAC AUTHORIZED
SERVICE DEALER, please call this number:

1-800-333-1322
OR
Locate us on the web at:

www.generac.com
Generac® Power Systems, Inc.

Table of Contents
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

INTRODUCTION ..................................IFC
SAFETY RULES ......................................2

Section 3 — OPERATION....................12
3.1

Using a Standard “GTS” Transfer Switch....12

3.2

Control Console Components......................13

Section 1 — GENERAL
INFORMATION..................4

3.3

Manual Transfer and Startup ......................13

3.4

Automatic Operation ..................................13

1.1

Generator ......................................................4

3.5

Weekly Exercise Cycle..................................13

1.2

Transfer Switch ............................................4

3.6

Engine Heater..............................................14

1.3

Automatic System Operation ........................4

Section 4 — MAINTENANCE ..............14

1.4

Generator AC Connection Systems................4

1.5

Main Circuit Breaker ....................................4

1.6

4.1

Maintenance Performed by Authorized
Service Facilities ..........................................14

Generator Fuel System ..................................4

4.2

Cooling System............................................15

1.7

Engine Protective Devices ..............................5

4.3

1.8

Unpacking ....................................................6

Overload Protection for Engine DC
Electrical System ........................................15

1.9

Lifting the Generator ....................................6

4.4

Checking Fluid Levels ................................15

1.10 Specifications ................................................7

4.5

Maintenance Owner/Operator
Can Perform ................................................16

4.6

Miscellaneous Maintenance ........................17

4.7

Scheduled Maintenance ..............................19

1.11 Fuel Consumption ........................................7
1.12 Reconfiguring the Fuel System ......................7
1.13 Torque Specifications ....................................8
1.14 Engine Oil Recommendations ......................8
1.15 Coolant Recommendations............................8
1.16 Before Installation ........................................8

Section 2 — INSTALLATION ................8

Section 5 — TROUBLESHOOTING......22
5.1

Troubleshooting Points................................22

Section 6 — NOTES............................23

2.1

Standby Generator Installation ....................8

Section 7 — INSTALLATION
DIAGRAM ......................25

2.2

Generator Location ......................................9

Section 8 — ELECTRICAL DATA ........26

2.3

Generator Mounting and Support ................9

2.4

Basic Standby Electric System ......................9

2.5

Emergency Circuit Isolation Method ..........10

2.6

Total Circuit Isolation Method ....................10

2.7

Grounding the Generator ............................10

2.8

Generator AC Neutral Connections ............10

2.9

Transfer Switch Start Signal Connections ..10

Section 9 — EXPLODED VIEWS AND
PARTS LISTS ................30
Section 10 — WARRANTY .................48

2.10 Battery Installation ......................................11
2.11 Preparation Before Start-Up ........................11

Generac® Power Systems, Inc.

IMPORTANT SAFETY INSTRUCTIONS
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

SAVE THESE INSTRUCTIONS – The manufacturer suggests that these rules for safe
operation be copied and posted in potential hazard areas. Safety should be stressed to all
operators, potential operators, and service and repair technicians for this equipment.

SAVE THESE INSTRUCTIONS – This manual contains important instructions that should be
followed during installation and maintenance of the generator and batteries.

WARNING:
The engine exhaust from this product
contains chemicals known to the state
of California to cause cancer, birth
defects or other reproductive harm.

WARNING:

This product contains or emits chemicals
known to the state of California to cause
cancer, birth defects or other reproductive harm.
Study these SAFETY RULES carefully before installing,
operating or servicing this equipment. Become familiar
with this Owner’s Manual and with the unit. The generator can operate safely, efficiently and reliably only if it is
properly installed, operated and maintained. Many accidents are caused by failing to follow simple and fundamental rules or precautions.
Generac cannot possibly anticipate every possible
cirumstance that might involve a hazard. The warnings in this manual, and on tags and decals affixed to
the unit are, therefore, not all-inclusive. If using a procedure, work method or operating technique that
Generac does not specifically recommend, satisfy yourself that it is safe for others. Also make sure the procedure, work method or operating technique chosen does
not render the generator unsafe.

DANGER

Despite the safe design of this generator,
operating this equipment imprudently, neglecting
its maintenance or being careless can cause
possible injury or death. Permit only responsible
and capable persons to install, operate or maintain this equipment.
Potentially lethal voltages are generated by these
machines. Ensure all steps are taken to render the
machine safe before attempting to work on the
generator.

Parts of the generator are rotating and/or hot
during operation. Exercise care near running generators.

Generac® Power Systems, Inc.

!
!

! GENERAL HAZARDS !
• For safety reasons, Generac recommends that this
equipment be installed, serviced and repaired by a
Generac Authorized Service Dealer or other competent, qualified electrician or installation technician
who is familiar with applicable codes, standards and
regulations. The operator also must comply with all
such codes, standards and regulations.
• Installation, operation, servicing and repair of this
(and related) equipment must always comply with
applicable codes, standards, laws and regulations.
Adhere strictly to local, state and national electrical
and building codes. Comply with regulations the
Occupational Safety and Health Administration
(OSHA) has established. Also, ensure that the generator is installed, operated and serviced in accordance
with the manufacturer’s instructions and recommendations. Following installation, do nothing that might
render the unit unsafe or in noncompliance with the
aforementioned codes, standards, laws and regulations.
• The engine exhaust fumes contain carbon monoxide
gas, which can be DEADLY. This dangerous gas, if
breathed in sufficient concentrations, can cause
unconsciousness or even death. For that reason, adequate ventilation must be provided. Exhaust gases
must be piped safely away from any building or
enclosure that houses the generator to an area where
people, animals, etc., will not be harmed. This
exhaust system must be installed properly, in strict
compliance with applicable codes and standards.
• Keep hands, feet, clothing, etc., away from drive belts,
fans, and other moving or hot parts. Never remove
any drive belt or fan guard while the unit is operating.
• Adequate, unobstructed flow of cooling and ventilating air is critical to prevent buildup of explosive gases
and to ensure correct generator operation. Do not
alter the installation or permit even partial blockage
of ventilation provisions, as this can seriously affect
safe operation of the generator.
• Keep the area around the generator clean and uncluttered. Remove any materials that could become hazardous.
• When working on this equipment, remain alert at all
times. Never work on the equipment when physically
or mentally fatigued.

IMPORTANT SAFETY INSTRUCTIONS
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

• Inspect the generator regularly, and promptly repair
or replace all worn, damaged or defective parts using
only factory-approved parts.
• Before performing any maintenance on the generator,
disconnect its battery cables to prevent accidental
start-up. Disconnect the cable from the battery post
indicated by a NEGATIVE, NEG or (–) first.
Reconnect that cable last.
• Never use the generator or any of its parts as a step.
Stepping on the unit can stress and break parts, and
may result in dangerous operating conditions from
leaking exhaust gases, fuel leakage, oil leakage, etc.

ELECTRICAL HAZARDS
• All generators covered by this manual produce dangerous electrical voltages and can cause fatal electrical
shock. Utility power delivers extremely high and dangerous voltages to the transfer switch as well as the
standby generator. Avoid contact with bare wires, terminals, connections, etc., on the generator as well as
the transfer switch, if applicable. Ensure all appropriate covers, guards and barriers are in place before
operating the generator. If work must be done around
an operating unit, stand on an insulated, dry surface
to reduce shock hazard.
• Do not handle any kind of electrical device while
standing in water, while barefoot, or while hands or
feet are wet. DANGEROUS ELECTRICAL SHOCK
MAY RESULT.
• If people must stand on metal or concrete while
installing, operating, servicing, adjusting or repairing
this equipment, place insulative mats over a dry
wooden platform. Work on the equipment only while
standing on such insulative mats.
• The National Electrical Code (NEC), Article 250
requires the frame and external electrically conductive parts of the generator to be connected to an
approved earth ground and/or grounding rods. This
grounding will help prevent dangerous electrical
shock that might be caused by a ground fault condition in the generator set or by static electricity. Never
disconnect the ground wire.
• Wire gauge sizes of electrical wiring, cables and cord
sets must be adequate to handle the maximum electrical current (ampacity) to which they will be subjected.
• Before installing or servicing this (and related) equipment, make sure that all power voltage supplies are
positively turned off at their source. Failure to do so
will result in hazardous and possibly fatal electrical
shock.
• Connecting this unit to an electrical system normally
supplied by an electric utility shall be by means of a
transfer switch so as to isolate the generator electric
system from the electric utility distribution system
when the generator is operating. Failure to isolate the
two electric system power sources from each other by
such means will result in damage to the generator
and may also result in injury or death to utility power
workers due to backfeed of electrical energy.

• Generators installed with an automatic transfer
switch will crank and start automatically when normal (utility) source voltage is removed or is below an
acceptable preset level. To prevent such automatic
start-up and possible injury to personnel, disable the
generator’s automatic start circuit (battery cables,
etc.) before working on or around the unit. Then,
place a “Do Not Operate” tag on the generator control
panel and on the transfer switch.
• In case of accident caused by electric shock, immediately shut down the source of electrical power. If this
is not possible, attempt to free the victim from the
live conductor. AVOID DIRECT CONTACT WITH
THE VICTIM. Use a nonconducting implement, such
as a dry rope or board, to free the victim from the live
conductor. If the victim is unconscious, apply first aid
and get immediate medical help.
• Never wear jewelry when working on this equipment.
Jewelry can conduct electricity resulting in electric
shock, or may get caught in moving components
causing injury.

FIRE HAZARDS
• Keep a fire extinguisher near the generator at all
times. Do NOT use any carbon tetra-chloride type
extinguisher. Its fumes are toxic, and the liquid can
deteriorate wiring insulation. Keep the extinguisher
properly charged and be familiar with its use.
Consult the local fire department for any questions
pertaining to fire extinguishers.

EXPLOSION HAZARDS
• Properly ventilate any room or building housing the
generator to prevent build-up of explosive gas.
• Do not smoke around the generator. Wipe up any fuel
or oil spills immediately. Ensure that no combustible
materials are left in the generator compartment, or
on or near the generator, as FIRE or EXPLOSION
may result. Keep the area surrounding the generator
clean and free from debris.
• Generac generator sets may operate using one of several types of fuels. All fuel types are potentially FLAMMABLE and/or EXPLOSIVE and should be handled
with care. Comply with all laws regulating the storage
and handling of fuels. Inspect the unit’s fuel system
frequently and correct any leaks immediately. Fuel
supply lines must be properly installed, purged and
leak tested according to applicable fuel-gas codes
before placing this equipment into service.
• Diesel fuels are highly FLAMMABLE. Gaseous fluids
such as natural gas and liquid propane (LP) gas are
extremely EXPLOSIVE. Natural gas is lighter than air,
and LP gas is heavier than air. Install leak detectors
accordingly.

Generac® Power Systems, Inc.

Section 1 - General Information
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

1.1

GENERATOR

1.3

AUTOMATIC SYSTEM OPERATION

This equipment is a liquid-cooled, engine-driven generator set. The generator is designed to supply electrical power that operates critical electrical loads
during utility power failure. The unit has been factory-installed in a weather resistant, all metal enclosure
and is intended for outdoor installation only. Use this
generator as a source of electrical power for the operation of 120 and/or 240 volts, single phase loads.

When this generator, along with its transfer switch, has
been installed and interconnected, a circuit board in
the generator panel constantly monitors utility power
source voltage. Should that voltage drop below a preset value, and remain at such a low state for a preset
amount of time, the generator cranks and starts. After
the generator starts, the transfer switch transfers load
circuits so the generator can power them.

These models are available. They are rated as follows:
Models 0047210 and 0047220: Provides 15,000
watts (15 kW) of single phase power.

When utility source voltage has been restored, the
switch re-transfers back to the utility source voltage
and the generator then shuts down.

Models 0047230 and 0047240: Provides 20,000
watts (20 kW) of single phase power.

Please reference the transfer switch manual for specific information.

Models 0047250, 0047251, 0047252, 0047253,
and 0047260: Provides 25,000 watts (25 kW) of single phase power.

1.4

1.2

If this generator is used to power electrical
load circuits normally powered by a utility
power source, it is required by code to install
a transfer switch. The transfer switch must
effectively isolate the electric system from the
utility distribution system when the generator
is operating (NEC 701). Failure to isolate an
electrical system by such means results in
damage to the generator and may also result
in injury or even death to utility power workers due to backfeed of electrical energy.

GENERATOR AC CONNECTION
SYSTEMS

The generator was shipped from the factory with its
stator AC output leads connected in a single-phase,
three-wire generator AC connection system (Figure
1.1). The stator assembly in this system consists of a
pair of stationary windings, with two leads brought
out of each winding. Each single winding can supply
120 volts AC, 60 Hertz. When the two windings are
connected in series, a 240 volts, 60 Hertz AC output
results. Typically the two “hot” leads in the circuit are
Wires No. 11 and 44. The “Neutral” leads are the
junction of Wires 22 and 33.

Figure 1.1 - Generator AC Connection System

TRANSFER SWITCH

This generator system may include a matched automatic transfer switch which is intended to be used in
conjunction with the Guardian generator. It is supplied in either a NEMA 1 enclosure (15 kW model
004721, 20 kW models 004723) or a NEMA 3R
enclosure (25 kW models 004725). The NEMA 1
enclosure is intended for indoor use only. The NEMA
3R enclosure is weather proof and can be used
indoors or outdoors. Follow these rules:
• Install the transfer switch on a firm, sturdy supporting structure.
• To prevent switch distortion, level the switch if necessary. This can be done by placing washers
between the switch enclosure and the mounting
surface.
• Never install the switch where water or any corrosive substance might drip onto the enclosure.
• Protect the switch at all times against excessive
moisture, dust, dirt, lint, construction grit and corrosive vapors.
• Failure to utilize a Generac/Guardian transfer
switch with this generator will void the warranty.
4

Generac® Power Systems, Inc.

1.5

MAIN CIRCUIT BREAKER

The generator’s main circuit breaker is included with
the unit as shipped from the factory. The breaker for
each unit is described in Figure 1.2 at the top of page
5.

1.6

GENERATOR FUEL SYSTEM

The generator has been factory tested and adjusted
using a natural gas fuel system. If propane (LP
requirements) gas is preferred, contact an authorized
service dealer. Refer to Secion 1.12.

Section 1 - General Information
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

Figure 1.2 - Main Circuit Breaker
Model

Rating

Phase

004721/004722
004723/004724
004725/004726

15,000
20,000
25,000

1
1
1

Actual Current

C/B Rating*

62.5
70
83.3
90
104.2
125
* Amp Rating of CB structured under model.

Recommended fuels should have a Btu content of at
least 1,000 Btus per cubic foot for natural gas and at
least 2,520 Btus per cubic foot for LP gas. Ask the
fuel supplier for the Btu content of the fuel being
used.
Fuel pressure for a natural gas set up should be five
inches to 14 inches of water column (0.18 to 0.5
psi) at all load ranges.

1.7.1

% over rating

Circuit Breaker

112%
108%
120%

70A BQ2
90A BQ2
125A BQ2

LOW OIL PRESSURE SWITCH

This switch is normally-closed (N.C.), but is held
open by engine oil pressure during engine running.
Should operating oil pressure drop below about 8-10
psi (55-68 kPa), the switch contacts close and the
engine shuts down automatically (Figure 1.4).

Figure 1.4 - Low Oil Pressure Switch

Fuel pressure for an LP vapor set up should be 11
inches to 14 inches of water column (0.4 to 0.5
psi) at all load ranges.
NOTE:
A seperate gas line and regulator may be needed
to assure proper gas pressure to the generator.
Improper gas pressure can cause hard starting and
affect engine durability.

1.7

Gaseous fuels such as natural and LP
(propane) gas are highly explosive. Even the
slightest spark can ignite such fuels and cause
an explosion. No leakage of fuel is permitted.
Natural gas, which is lighter than air, tends to
collect in high areas. LP gas is heavier than air
and tends to settle in low areas.

ENGINE PROTECTIVE DEVICES

The engine has several safety switches which cause
the engine to automatically shut down under the following conditions: low oil pressure, high coolant temperature, engine overspeed, low coolant level or overcrank (Figure 1.3).

1.7.2 HIGH COOLANT TEMPERATURE SWITCH
This normally open (N.O.), thermostatic switch has
sensing tip which is immersed in captive coolant.
Should coolant temperature exceed about 230°F
(110°C), the switch contacts close, which causes the
engine to shut down automatically (Figure 1.5).

Figure 1.5- High Coolant Temperature Switch

Figure 1.3 - Engine Protective Devices

1.7.3

LOW COOLANT LEVEL SWITCH

Should engine coolant level drop below the level of
the high coolant temperature switch, it is possible for
the engine to overheat without automatic shutdown.
To prevent such overheating without automatic shut
down, the engine has a low coolant level sensor. If the
engine coolant drops too low, the engine automatically shuts down (Figure 1.6 on page 6).
Generac® Power Systems, Inc.

Section 1 — General Information
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

• LED 2 is YELLOW. This LED is on when the circuit
board battery charger is on. This LED will cycle on
and off with the battery charger, 4.85 hours on the
4.85 hours off.
• LED 3 is GREEN. This LED will flash when the circuit board has load voltage available to it. This
LED will function when voltage is available across
T1 and T2.

Figure 1.6 - Low Coolant Level Sensor

1.7.6

OVERCRANK SHUTDOWN

After 90 seconds of crank-rest cycles, this function
ends cranking if the engine fails to start in that
90-second span.

1.7.4

1.7.6

OVERSPEED SHUTDOWN

The Pre-pack circuit board on liquid cooled units
receives AC frequency (rpm) signals directly from the
stator AC power windings, via sensing leads S15 and
S16. Should AC frequency exceed about 72 Hz, circuit board action will automatically shutdown the
engine (Figure 1.7).
*Rated power of generator is subject to and limited by such factors as ambient temperature, altitude, engine condition, and other factors. Engine
power will decrease about 3.5% for each 1000 feet
above sea level and will decrease an additional 1%
for each 10°F above 60°F. Maximum output power
of the generator is limited by maximum engine
power.

Figure 1.7 - Control Module Assembly
Circuit Board
R72

R71

R70

CR8

CR19

R69

J2
M14

U13

PRE-PACKAGED STANDBY

U14

M
M5

R54

M3
R84

R75

R
R77

C18

R76

Q14

C12
M10

R68 R60
C21

C25

SW1

BR1

U12

R56

CR1

Q9
R12

C22

U16

LED3

C24

C3
U2

Q1
U6

R51

R48

R74

R52

CR3

U18

R4
CR12

U19
R24

R23

CR13

CR14

CR15

CR36

R37

CR20
R38

R39
R35

R41

R36

R40

R31

R30

R19

R21
R20

R18

R22

R82

R67

CR21

CR17

C23

R32

R33

R29
R27

Q12

CR18

R50

CR38

R17

R5
R6

R13

R15

R14

CR37

CR2

CR7

R16

R11 R10

C19

U10

Q2
R78

LED2

Handle shipping cartons and crates with care. Use
care to avoid damage from dropping, bumping, collision, etc. Store and unpack cartons with the proper
side up, as noted on the shipping carton.

INSPECTION

After unpacking, carefully inspect the generator for
any damage that may have occurred during shipment. If loss or damage is noted at the time of delivery, have the person(s) making delivery note all damage on the freight bill or affix their signature under
the consignor’s memo of loss or damage.

1.9

LIFTING THE GENERATOR

C10

C 1
C11

U20

Q16

R63

C16

R83

R87

2002 GENERAC POWER SYSTEMS, ASSY #076009A

R88

C13

R43

R42
R44

R46

R47

R65

R61

R59

CR30

R57

R55

CR32

Q13

R53

R81

R66

CR35

CR33

LED1
Q6

CUT R83
FOR 50HZ

PCB OPERATION LED’S

• LED 1 is RED. The LED is on when utility sensing
is NOT available to the circuit board. This LED will
function only when the Auto/Off/Manual switch is
set in the Auto position.

UNPACKING PRECAUTIONS

R62

Q15

1.7.5

1.8.1

R86

R85

R26

R25

CR16

C15

CR41

UNPACKING

C8
Q11

C14

1.8

C20

CR24

CR29

CR34

CR40

This clearly labeled fuse is located on the front panel
of the control system. It protects the panel wiring and
components from damaging overload. Always
remove this fuse before commencing work on the
generator. The unit will not start or crank if the fuse
is blown. Replace the fuse with one of the same size,
type, and rating. Generac normally uses an AGC fuse
rated at 15 amps (part number 022676).

1.8.2

U17

C17

Q7
R1

U15

M15

M8
M
M1

DC FUSE

Generac® Power Systems, Inc.

When lifting or hoisting equipment is used,
be careful not to touch overhead power lines.
The generators weight of more than 900
pounds requires proper tools, equipment, and
qualified personnel to be used in all phases of
handling and unpacking.

Section 1 — General Information
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

NOTE:

1.10 SPECIFICATIONS
1.10.1 GENERATOR SPECIFICATIONS
Single-Phase
Model
Rated Max. Cont.
AC Power Output (kW)
Rated voltage (volts)
No. of Rotor Poles
Driven Speed of Rotor
Rotor Excitation System
Type of Stator
Rotor/Stator Insulation

004725 004723 004721
004726 004724 004722
25

120/240
2

4
3600
3600
1800
Direct excited brush type
4 Wire
Class F

1.10.2 ENGINE SPECIFICATIONS
Make..............................................................................Mitsubishi
Displacement ..............................................92 inches3 (1.5 liters)
Cylinder Arrangement......................................................4, in-line
Valve Arrangement................................................Overhead Cam
Firing Order........................................................................1-3-4-2
Number of Main Bearings............................................................5
Compression Ratio ..............................................................9 to 1
No. of Teeth on Flywheel ........................................................104
Ignition Timing
at 1800 rpm ..................................................35 degrees BTDC
at 3600 rpm ..................................................43 degrees BTDC
Spark Plug Gap ..................................................0.020-0.025 inch
Recommended Spark Plugs
Champion ....................................................................RN11YC4
Oil Pressure....................................................................30-50 psi
Crankcase Oil Capacity........................3.0 U.S. quarts (2.8 liters)
Recommended Engine Oil........................................SAE 15W-40
Type of Cooling System ..................Pressurized, closed recovery
Cooling Fan ..............................................................Pusher Type
Cooling System Capacity ......................2 U.S. gallons (7.6 liters)
Recommended Coolant ............................Use a 50-50 mixture of
ethylene glycol base.

1.11 FUEL CONSUMPTION
25 kW Models
Using Natural Gas ........................................441 cu. ft. per hour
Using LP Gas ..............................175 cubic ft.(4.8 gal.) per hour
20 kW Models
Using Natural Gas ........................................359 cu. ft. per hour
Using LP Gas ............................143 cubic ft. (4.0 gal.) per hour
15 kW Models
Using Natural Gas ........................................277 cu. ft. per hour
Using LP Gas ..............................110 cubic ft.(3.1 gal.) per hour

Fuel consumption is given at rated maximum continuous power output when using natural gas
rated at 1000 Btu per cubic foot and LP gas rated
2520 Btu per cubic foot. Actual fuel consumption
obtained may vary depending on such variables as
applied load, ambient temperature, engine conditions and other environmental factors.
Fuel pressure for a natural gas set up should be five
inches to 14 inches of water column (0.18 to 0.5
psi) at all load ranges.
Fuel pressure for an LP vapor set up should be 11
inches to 14 inches of water column (0.4 to 0.5
psi) at all load ranges.

1.12 RECONFIGURING THE FUEL
SYSTEM
NOTE:
All models are configured for natural gas from the
factory.
To reconfigure the fuel system from NG to LP, follow
these steps:
1. Turn the main gas supply off.
2. Remove the carburetor fuel hose from the outlet
port (Port 1) of the demand regulator (Figure
1.8).
3. Remove the brass hose fitting from the outlet port
(Port 1) of the demand regulator.
4. Remove pipe plug from Port 2.
5. Install brass hose fitting into Port 2.
6. Install pipe plug into Port 1.
7. Connect carburetor gas hose to brass fitting.
8. Tighten all clamps and plugs.
9. Make sure fuel supply is of the proper pressure
and type for configuration.
10. Reverse the procedure to convert back to natural
gas.

Figure 1.8 — Reconfigure the Fuel System
Port 2

Port 1

PLUG

FUEL HOSE

BRASS HOSE
FITTING
OUT
PORT 1

BRASS HOSE
FITTING

HOUSING
PORTS

NG FUEL SYSTEM

PLUG

OUT
PORT 2
HOUSING
PORTS

LP FUEL SYSTEM

Generac® Power Systems, Inc.

Section 2 — Installation
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

NOTE:

1.16 BEFORE INSTALLATION

Port 1 is for NG only and Port 2 is for LP vapor
only. No provision for simultaneous fuels has been
made.

Before installing this equipment, check the ratings of
both the generator and the transfer switch. Read
“Emergency Isolation Method” and “Total Circuit
Isolation Method” in Sections 2.5 and 2.6.

DANGER

The generator’s rated wattage/amperage capacity
must be adequate to handle all electrical loads that
the unit will power. The critical (essential) loads may
need to be grouped together and wired into a separate “emergency” distribution panel.

Serious injury or damage may occur if not configured properly. Please consult an authorized
Generac Service Dealer with any questions.

1.13 TORQUE SPECIFICATIONS
Cylinder Head ............................................15 (+ 90° + 90°) ft.lb.
Intake Manifold ................................................................13 ft.lb.
Exhaust Manifold..............................................................13 ft.lb.

1.14 ENGINE OIL RECOMMENDATIONS
The unit has been filled with 15W-40 engine oil at the
factory. Use a high-quality detergent oil classified “For
Service CC, SD, SE, SF.” Detergent oils keep the engine
cleaner and reduce carbon deposits. Use oil having the
following SAE viscosity rating, based on the ambient
temperature range anticipated before the next oil
change:
Temperature
Above 80° F (27° C)
32° to 80° F (-1° to 27° C)
Below 32° F (0° C)

2.1

Do not use any chromate base rust inhibitor
with ethylene glycol base anti-freeze or chromiumhydroxide (“green slime”) forms and will
cause overheating. Engines that have been
operated with a chromate base rust inhibitor
must be chemically cleaned before adding ethylene glycol base anti-freeze. Using any high
silicate anti-freeze boosters or additives will
also cause overheating. Generac Power Systems
also recommends that any soluble oil inhibitor
is NOT used for this equipment.
Generac® Power Systems, Inc.

STANDBY GENERATOR
INSTALLATION
DANGER
Connecting this generator to an electrical system normally supplied by an electric utility
shall be by means of a transfer switch, so as
to isolate the electric system from the utility
distribution system when the generator is
operating. Failure to isolate the electric system by these means will result in damage to
the generator and may also result in injury or
death to utility workers due to backfeed of
electrical energy.

Any attempt to crank or start the engine before
it has been properly serviced with the recommended oil may result in an engine failure.

Use a mixture of half low silicate ethylene glycol base
anti-freeze and deionized water. Cooling system
capacity is about 8 U.S. quarts (7.6 liters). Use only
deionized water and only low silicate anti-freeze. If
desired, add a high quality rust inhibitor to the recommended coolant mixture. When adding coolant,
always add the recommended 50-50 mixture.

The standard transfer switch has no sensing or controlling circuit boards. Instead, the generator control
console houses a “Printed Circuit Board Assembly”,
which controls all phases of operation, including
engine start up and load transfer.

Oil Grade (Recommended)
SAE 30W or 15W-40
SAE 20W-20 or 15W-40
SAE 10W or 15W-40

1.15 COOLANT RECOMMENDATIONS

This generator can be installed in conjunction with a
standard Generac “GTS” type transfer switch, if
desired.

If an open bottom is used, the engine-generator is to be installed over non-combustible
materials and should be located such that combustible materials are not capable of accumulating under the generator set.
Only qualified, competent installation contractors or
electricians thoroughly familiar with applicable
codes, standards and regulations should install this
standby electric power system. The installation must
comply strictly with all codes, standards and regulations pertaining to the installation.
This genset must be installed on a level surface. The
base frame must be level within 1/2 inch all around.

After the system has been installed, do nothing
that might render the installation in noncompliance with such codes, standards and regulations.

Section 2 — Installation
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

2.1.1

NFPA STANDARDS

The following published standards booklets pertaining to standby electric systems are available form the
National Fire Protection Association (NFPA),
Batterymarch Park, Quincy, MA 02269:
• NFPA No. 37, STATIONARY COMBUSTION
ENGINES AND GAS TURBINES.
• NFPA No. 76A, ESSENTIAL ELECTRICAL SYSTEMS FOR HEALTH CARE FACILITIES.
• NFPA No. 220, STANDARD TYPES OF BUILDING
CONSTRUCTION
• NFPA No. 68, GUIDE FOR EXPLOSION VENTING
• NFPA No. 70, NATIONAL ELECTRICAL CODE.
• NFPA No. 30, FLAMMABLE AND COMBUSTIBLE
LIQUIDS CODE.
• NFPA No. 10, INSTALLATION, MAINTENANCE AND
USE OF PORTABLE FIRE EXTINGUISHERS.

2.1.2

OTHER PUBLISHED STANDARDS

In addition to NFPA standards, the following information pertaining to the installation and use of
standby electric systems is available:
• Article X, NATIONAL BUILDING CODE, available
from the American Insurance Association, 85 John
Street, New York, N.Y. 10038.
• AGRICULTURAL WIRING HANDBOOK, obtainable
from the Food and Energy Council, 909 University
Avenue, Columbia, MO, 65201.
• ASAE EP-364.2, INSTALLATION AND MAINTENANCE OF FARM STANDBY ELECTRIC POWER,
available from the American Society of Agricultural
Engineers, 2950 Niles Road, St. Joseph, MI 49085.
• A52.1, AMERICAN NATIONAL STANDARD FOR
CHIMNEYS, FIREPLACES AND VENTING SYSTEMS, available from the American National
Standard Institute, 1430 Broadway, New York, N.Y.
10018.

2.2

• Install the generator as close as possible to the
transfer switch. This reduces the length of wiring
and conduit.
• Install the generator as close as possible to the fuel
supply, to reduce the length of piping. HOWEVER,
REMEMBER THAT LAWS OR CODES MAY REGULATE THE DISTANCE.

2.3

GENERATOR MOUNTING AND
SUPPORT

Retain the generator compartment to a concrete slab
with 1/4-inch masonry type anchor bolts. Be sure the
bolts are long enough to retain the compartment. The
slab should be at least six inches thick and should
extend beyond the enclosure to a distance of at least
three inches on all sides. See Section 7, Installation
Diagram.

2.4

BASIC STANDBY ELECTRIC
SYSTEM

Figure 2.1 shows a schematic diagram of a basic
standby electric system. Both the UTILITY power
supply and the STANDBY (generator) output are connected to an approved transfer switch. The transfer
switch is required by electrical code and serves the
following functions:
• Permits the LOAD circuits to be connected to only
one power supply at a time.
• Prevents electrical backfeed between the generator
and the UTILITY power circuits.
Notice that both the STANDBY and the UTILITY
power supplies to the transfer switch are protected
against overload by a main line circuit breaker.

Figure 2.1 – Basic Standby Electric System

GENERATOR LOCATION

Install the generator set, in its protective enclosure
outdoors, where adequate cooling and ventilating air
always is available. Consider these factors:
• Install the unit where air inlet and outlet openings
will not become obstructed by leaves, grass, snow,
etc. If prevailing winds will cause blowing or drifting, consider using a windbreak to protect the unit.
• Install the generator on high ground where water
levels will not rise and endanger it.
• Allow sufficient room on all sides of the generator
for maintenance and servicing. A good rule is to
allow five feet of space on all sides.
• Where strong prevailing winds blow from one
direction, face the generator air inlet openings into
the prevailing winds.

NOTE:
Generac recommends the use of a Generac Power
Systems “GTS” type transfer switch in conjunction with this generator.
Generac® Power Systems, Inc.

Section 2 — Installation
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

2.5

EMERGENCY CIRCUIT ISOLATION
METHOD

This prevents overloading the generator by keeping
electrical loads below the wattage/amperage capacity
of the generator. If the generator is powering only critical loads, within the wattage/amperage capacity, during utility power outages, consider using the emergency circuit isolation method.

Proper grounding helps protect personnel against
electrical shock in the event of a ground fault condition in the generator or in connected electrical
devices. In addition, grounding helps dissipate static
electricity that often builds up in ungrounded
devices.

Figure 2.2 – Generator Grounding Lug (typical)

Critical electrical loads are grouped together and
wired into a separate “Emergency Distribution
Panel.” Load circuits powered by that panel are within the wattage/amperage capacity of the generator set.
When this method is used, it is difficult to overload
the generator. The transfer switch must meet the following requirements:
• It must have an ampere rating equal to, or greater
than, the total amperage rating of the emergency
distribution panel circuit.
• Have it installed between the building’s main distribution panel and the emergency distribution
panel.

2.6

TOTAL CIRCUIT ISOLATION
METHOD

When a generator capable of powering all electrical
loads in the circuit is to be installed, use the “Total
Circuit Isolation Method.” It is possible for the generator to be overloaded when this isolation method is
employed. The following apply to the transfer switch
in this type of system.
• Ampere rating of the transfer switch must be equal
to, or greater than, the ampere rating of the normal
incoming utility service.
• The transfer switch is installed between the utility
service entrance and the building distribution
panel.

2.7

GROUNDING THE GENERATOR

The National Electrical Code requires the frame and
external electrically conductive parts of this equipment to be properly connected to an approved earth
ground and/or grounding rods. For that purpose, a
GROUND LUG (Figure 2.2) is provided on the generator mounting base. Consult a qualified electrician
for grounding requirements in the area. Grounding
procedures must meet local regulations.

DANGER
Do not connect the ground wire to any pipe
that carries a flammable or explosive substance
– FIRE or an EXPLOSION may result.

10 Generac® Power Systems, Inc.

2.8

GENERATOR AC NEUTRAL
CONNECTIONS

Generac Power Systems uses an UNGROUNDED AC
neutral. Grounding is recommended only at the main
service entrance. If the neutral wire is grounded and
one of the phase loads becomes grounded, the excessive current opens the load circuit breaker or collapses the generator field. The actual result depends
on the electrical characteristics of the particular
installed generator.

2.9

TRANSFER SWITCH START SIGNAL
CONNECTIONS

If the generator is to be installed with an automatic
transfer switch, such as an engineered Generac GTStype switch, it is necessary to connect the two-wire
start control system.
Connect the two-wire start signal from the automatic
transfer switch to the automatic start connection,
which is located in the right hand corner inside the
control panel. Match wires 178 and 183 in the transfer switch to 178 and 183 on the terminal strip in the
control panel. The conductors for the two-wire start
circuit must be in their own conduit.

Section 2 — Installation
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

2.10 BATTERY INSTALLATION
DANGER

Standby generators installed with automatic
transfer switches will crank and start automatically when NORMAL (UTILITY) source voltage is
removed or is below an acceptable preset level.
To prevent such automatic start-up and possible
injury to personnel, do not connect battery
cables until the NORMAL source voltage at the
transfer switch is correct and the system is
ready to be put into operation.
Storage batteries give off explosive hydrogen
gas. This gas can form an explosive mixture
around the battery for several hours after
charging. The slightest spark can ignite the gas
and cause an explosion. Such an explosion can
shatter the battery and cause blindness or
other injury. Any area that houses a storage
battery must be properly ventilated. Do not
allow smoking, open flame, sparks or any spark
producing tools or equipment near the battery.

Battery electrolyte fluid is an extremely caustic
sulfuric acid solution that can cause severe
burns. Do not permit fluid to contact eyes, skin,
clothing, painted surfaces, etc. Wear protective
goggles, protective clothing and gloves when
handling a battery. If the fluid is spilled, flush
the affected area immediately with clear water.

Do not dispose of the battery in a fire. The battery is capable of exploding.
Do not open or mutilate the battery. Released
electrolyte can be toxic and harmful to the skin
and eyes.
The battery represents a risk of high short circuit current. When working on the battery,
always remove watches, rings or other metal
objects, and only use tools that have insulated
handles.

2.10.1 VENTED BATTERIES

The electrolyte is a dilute sulfuric acid that is
harmful to the skin and eyes. It is electrically
conductive and corrosive. The following procedures are to be observed:
• Wear full eye protection and protective clothing,
• Where electrolyte contacts the skin, wash it off
immediately with water,
• Where electrolyte contacts the eyes, flush thoroughly and immediately with water and seek medical attention, and

• Spilled electrolyte is to be washed down with an
acid-neutralizing agent. A common practice is to
use a solution of one pound (500 grams) bicarbonate of soda to one gallon (4 liters) of water. The
bicarbonate of soda solution is to be added until
the evidence of reaction (foaming) has ceased. The
resulting liquid is to be flushed with water and the
area dried.
Lead acid batteries present a risk of fire
because they generate hydrogen gas. The following procedure are to be followed:
• DO NOT SMOKE when near batteries,
• DO NOT cause flame or spark in battery area, and
• Discharge static electricity from body before touching batteries by first touching a grounded metal
surface.
Servicing of batteries is to be performed or supervised by personnel knowledgeable of batteries and
the required precautions. Keep unauthorized personnel away from batteries.
The recommended battery is Group 26, 12V negative
ground, 525 CCA/75 AH minimum. All batteries must
be at 100 percent state-of-charge before they are
installed on the generator.
When using maintenance-free batteries, it is not necessary to check the specific gravity or electrolyte level.
Have these procedures performed at the intervals
specified in Section 4, “Maintenance.” A negative
ground system is used. Battery connections are
shown on the wiring diagrams. Make sure all batteries are correctly connected and terminals are tight.
Observe battery polarity when connecting batteries
to the generator set.
NOTE:
Damage will result if the battery connections are
made in reverse.

2.11 PREPARATION BEFORE START-UP
The instructions in this section assume that the
standby generator has been properly installed, serviced, tested, adjusted and otherwise prepared for use
by a competent, qualified installation contractor. Be
sure to read the “Safety Rules” on Pages 2 and 3, as
well as all other safety information in this manual,
before attempting to operate this (and related) equipment.

2.11.1 PRIOR TO INITIAL START-UP

Prior to initially starting the generator, it must
be properly prepared for use. Any attempt to
crank or start the engine before it has been
properly serviced with the recommended types
and quantities of engine fluids (oil, coolant,
fuel, etc.) may result in an engine failure.
Generac® Power Systems, Inc. 11

Section 3 — Operation
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

Before starting the generator for the first time, the
installer must complete the following procedures. For
follow-up maintenance information and/or service
intervals, please refer to Section 4, “Maintenance.”

2.11.2 TRANSFER SWITCH
If this generator is used to supply power to any electrical system normally powered by an electric utility,
the National Electrical Code requires that a transfer
switch be installed. The transfer switch prevents electrical backfeed between two different electrical systems. (For additional information, see the applicable
transfer switch manual for this unit.) The transfer
switch, as well as the generator and other standby
components, must be properly located and mounted
in strict compliance with applicable codes, standards
and regulations.

2.11.3 FUEL SYSTEM
Make sure the fuel supply system to the generator (a)
delivers the correct fuel at the correct pressure and
(b) is properly purged and leak tested according to
code. No fuel leakage is permitted. See
“Specifications” (Section 1.10) for more information.

2.11.4 GENERATOR SET LUBRICATION
Check the engine crankcase oil level before operating
and add oil to the proper level – the dipstick “FULL”
mark. Never operate the engine with the oil level
below the dipstick “ADD” mark. See “Specifications”
(Section 1.10) and “Engine Oil Recommendations”
(Section 1.14).
NOTE:
This engine is shipped from the manufacturer
with 15W-40 oil. This oil should be changed after
30 hours of operation.

2.11.5 ENGINE COOLANT
Have the engine cooling system properly filled with
the recommended coolant mixture. Check the system
for leaks and other problems. See “Specifications”
(Section 1.10) and “Coolant” (Section 1.15).

2.11.6 BELT TENSION
Check the engine fan belt tension and condition prior
to placing the unit into service and at recommended
intervals. Belt tension is correct when a force of
approximately 22 pounds (10 kg), applied midway
between pulleys, deflects the belt about 3/8- to 5/8inch (10 to 16 mm).

12 Generac® Power Systems, Inc.

2.11.7 ELECTRICAL SYSTEM
Make sure the generator is properly connected to an
approved earth ground and/or ground rod.
Make sure the generator battery is fully charged,
properly installed and interconnected, and ready for
use.
Check to ensure that there are no loose electrical connections. Restrain any loose wires to keep them clear
of any moving generator set components.

3.1

USING A STANDARD “GTS”
TRANSFER SWITCH

When required, the pre-packaged standby generator
can be installed with a Generac “GTS” type engineered automatic transfer switch.
When a GTS type transfer switch is used, it controls
automatic operation and automatic transfer as follows:
• Solid state circuits in the transfer switch monitor
utility power source voltage.
• When utility source voltage drops below a pre-set
level, transfer switch action closes the circuit. The
engine then cranks and starts as controlled by the
pre-packaged generator’s Control Module circuit
board.
• After the engine starts and when the generator AC
output voltage and frequency have reached a
pre-set value, transfer switch circuits signal the
transfer switch main contacts to actuate to the
“Standby” power source side. Generator AC output
then powers load circuits.
• When the utility power source voltage is restored
above a pre-set level, transfer switch solid state
circuits signal the switch main contacts to move
back to their utility power source side.
• Following re-transfer back to the utility power
source side, transfer switch circuit board action
opens the circuit. Engine then shuts down.
NOTE:
If the generator is installed in conjunction with a
GTS type transfer switch, refer to the applicable
transfer switch manual for exact operating parameters and timing sequences.

Section 3 - Operation
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

3.2

CONTROL CONSOLE
COMPONENTS

The components of a liquid-cooled generator control
console (Figure 3.1) are as follows:

Figure 3.1 - Liquid-Cooled Generator Panel

3.2.4

The fuse protects the control console’s DC control
circuit against electrical overload. If the fuse has
melted open because of an overload, engine cranking
and startup cannot occur. If replacement of the fuse
is necessary, use only an identical 15-amp fuse. (Type
AGC, part number 022676).

3.2.5
HOUR METER

FUSE
15-A
AGC

FAULT
INDICATOR

AUTO
SET
EXERCISE
TIME

OFF

15 AMP FUSE

7.5 AMP INLINE FUSE

This inline fuse is connected in the 15A line that runs
between the AUTO/OFF/MANUAL switch and position
10 of the 76009A PCB. This fuse protects the start,
fuel, field boost, and transfer outputs from the PCB
and will open if there is excessive current draw on
any one of these outputs.

NOTE:

MANUAL

3.2.1

HOURMETER

Indicates time the engine-generator has operated, in
hours and tenths of hours. Use the hourmeter along
with the periodic maintenance schedule for the generator set.

3.2.2

AUTO/OFF/MANUAL SWITCH

Use this three-position switch as follows:
• Set the switch to AUTO for fully automatic operation. See “Automatic Operation”, Section 3.4.
• Set switch to MANUAL position to crank and start
the generator engine.
• Set switch to OFF position to shut down an operating engine. With OFF selected, operation will not
be possible.

DANGER

With switch set to AUTO, engine can crank
and start suddenly without warning. Such
automatic start up normally occurs when utility source voltage drops below a pre-set level.
To prevent possible injury that might be
caused by such sudden starts, set
AUTO/OFF/MANUAL switch to OFF before
working on or around the unit. Then, place a
"DO NOT OPERATE" tag on control console.

3.2.3

FAULT INDICATOR LAMP

The lamp goes ON when one or more of the following
engine faults occurs and when engine shuts down.
• Low oil pressure
• High coolant temperature
• Low coolant level

• Overcrank
• Overspeed

This fuse will not remove the positive (+) battery
input power from the PCB when it opens. This
means the exercise timer will not be reset. If this
fuse does open, carefully check the wiring to the
start, fuel, field boost and transfer outputs before
replacing the fuse.

3.2.6

SET EXERCISE TIME SWITCH

This switch allows for programming the generator to
start and exercise automatically. See “Weekly
Exercise Cycle” (Section 3.5).

3.3

MANUAL TRANSFER AND
START-UP

To transfer electrical loads to the STANDBY (GENERATOR) power source side and start the engine
manually, refer to the Owner’s Manual of the particular transfer switch.

3.4

AUTOMATIC OPERATION

To set the system for fully automatic operation, proceed as follows:
• Check that load circuits are connected to the
utility power supply.
• Set the AUTO/OFF/MANUAL switch to its AUTO
position.
• Set the generator main circuit breaker to its ON or
CLOSED position.

3.5

WEEKLY EXERCISE CYCLE

The generator will start and exercise once every seven
days. During this weekly exercise, the unit runs for
about 20 minutes and shuts down. Transfer of loads
to generator output does not occur during the exercise.
To select day and time for exercising, proceed as
follows:
Generac® Power Systems, Inc. 13

Section 4 — Maintenance
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

• Set the AUTO/OFF/MANUAL switch to OFF.
• Set generator main circuit breaker to OFF or
OPEN.
• Locate the rocker switch on the control panel identified with the words “Set Exercise Time” (Figure
3.2).
• Push “Set Exercise Time” switch to ON position for
20 to 30 seconds and then release. Switch will
spring back into its original position when
released.
• Wait 30 seconds before setting the AUTO/OFF/
MANUAL switch to AUTO position.

If the AUTO/OFF/MANUAL switch is switched
too soon, the engine may start. If engine does
start, it will shut down automatically in about
two (2) minutes.
• Set the generator main circuit breaker to its ON or
CLOSED position.
• Generator is now programmed to start and exercise every seven days thereafter, on day and time of
day the switch was actuated.
• Place a sign on the generator control panel and the
transfer switch, indicating the day and time the
generator will be exercising.
NOTE:

If battery terminals are disconnected, the exercise
timer needs to be reset for correct automatic exercise operation.

Figure 3.2 - “Set Exercise” Switch

Figure 3.3 - Engine Block Heater

Refer to applicable wiring diagram(s) and electrical
schematic(s) at back of manual for wiring connections. Customer supplies a 120V 15A Utility fed circuit for the block heater.

4.1

MAINTENANCE PERFORMED BY
AUTHORIZED SERVICE FACILITIES

A. EVERY THREE MONTHS
1.Check battery state of charge and condition.
2.Inspect and test fuel system.
3.Check transfer switch.
4.Inspect exhaust system.
5.Check engine ignition system.
6.Check fan belts.

B. ONCE EVERY SIX MONTHS
1.Test Engine Safety Devices (low oil pressure, low
coolant level, high coolant temperature).

C. ONCE ANNUALLY
1.Test engine governor. Adjust or repair, if needed.
2.Clean, inspect generator.
3.Flush cooling system.

D. FIRST 100 OPERATING HOURS

3.6

ENGINE HEATER

This standby generator comes equipped with a block
heater (Figure 3.3), similar to the block heaters used
in automotive applications. The block heater is wired
to a grounded plug.

14 Generac® Power Systems, Inc.

1.Change engine oil and oil filter. (After initial
change, service engine oil and filter at 150 operating hours or six months, whichever comes
first.)
2.Retorque cylinder head. (See Torque Specs,
Section 1.13.)
3.Retorque intake and exhaust manifold. (See
Torque Specs, Section 1.13.)

Section 4 — Maintenance
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

E. EVERY 500 OPERATING HOURS
1.Service air cleaner.
2.Check starter.
3.Check engine DC alternator.

F. EVERY 800 OPERATING HOURS
1.Retorque cylinder head. (See Torque Specs,
Section 1.13.)
2.Retorque intake and exhaust manifold. (See
Torque Specs, Section 1.13.)
3.Check engine compression.
4.Check valve clearance.

4.2

COOLING SYSTEM

Air intake and outlet openings in the generator compartment must be open and unobstructed for continued proper operation. This includes such obstructions as high grass, weeds, brush, leaves and snow.

4.4

CHECKING FLUID LEVELS

4.4.1

CHECK ENGINE OIL

Check engine crankcase oil level (Figure 4.1) at least
every 20 hours of operation, or prior to use.
• Remove oil dipstick and wipe dry with a clean,
lint-free cloth.
• Install oil dipstick, then remove again.
• Oil should be between FULL and ADD marks.
• If oil level is below the dipstick ADD mark, remove
oil fill cap. Add the recommended oil to bring oil
level up to the FULL mark. DO NOT FILL ABOVE
THE “FULL” MARK. See Section 1.14 for recommended oils.

Figure 4.1 - Oil Dipstick and Oil Fill Cap
OIL DIPSTICK

Without sufficient cooling and ventilating air flow, the
engine/generator quickly overheats, which causes it
to shut down. (See Section 7 for installation drawings
and vent locations.)

The exhaust system parts from this product get
extremely hot and remains hot after shutdown.
High grass, weeds, brush, leaves, etc. must
remain clear of the exhaust. Such materials may
ignite and burn from the heat of the exhaust
system.

4.3

OVERLOAD PROTECTION FOR
ENGINE DC ELECTRICAL SYSTEM

Engine cranking, start up and running are controlled
by a solid state Engine Controller circuit board.
Battery voltage is delivered to that circuit board via a
15 amp fuse. These overcurrent protection devices
will open if the circuit is overloaded.

4.4.2

BATTERY FLUID

Check battery electrolyte fluid at least once weekly.
Fluid should cover separators in all battery cells. If
fluid level is low, add distilled water to cover tops of
separators. DO NOT USE TAP WATER IN BATTERY.

4.4.3

ENGINE COOLANT

Check coolant level in coolant recovery bottle. See
Specifications, Section 1.10.

If a circuit breaker opens or a fuse element
melts, find the cause of the overload before
resetting the circuit breaker or replacing the
fuse.

• Add recommended coolant mixture as necessary.
• Periodically remove radiator pressure cap to make
sure the coolant recovery system is functioning
properly. Coolant should be at bottom of radiator
filler neck. If coolant level is low, inspect gasket in
radiator pressure cap. Replace cap, if necessary.
To have pressure cap tested, contact an authorized
Generac Service Dealer. Inspect cooling system
and coolant recovery system for leaks.

Generac® Power Systems, Inc. 15

Section 4 — Maintenance
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

4.5

MAINTENANCE OWNER/
OPERATOR CAN PERFORM

4.5.1

CHECK ENGINE OIL LEVEL

Refer to “Checking Fluid Levels” in Section 4.4.

4.5.2

CHECK BATTERY

• Check battery fluid level each week as outlined
under “Check Fluid Levels”.
• Check battery cables for condition, tightness, corrosion or damage. Clean, tighten or replace as
necessary.

4.5.3

EXERCISE SYSTEM

Start the generator engine at least once every seven
days and let it run at least 20 minutes. See Section
3.5, “Weekly Exercise Cycle”.

4.5.4

INSPECT COOLING SYSTEM

• Inspect engine cooling system at least once each
month.
• Check hoses for damage, deterioration, leaks, etc.
Correct any discrepancies found.
• Check hose clamps for tightness.

4.5.5

CHECK ENGINE COOLANT LEVEL

See “Checking Fluid Levels” in Section 4.4.

4.5.6

PERFORM VISUAL INSPECTION

Complete a thorough visual inspection of the entire
engine-generator monthly. Look for obvious damage,
loose, missing or corroded nuts, bolts and other fasteners. Look for fuel, oil or coolant leaks.

4.5.7

DANGER

DANGER: Do not attempt to adjust the governor. Only qualified service facilities should
adjust the governor. Excessively high operating speeds are dangerous and increase the
risk of personal injury. Low speeds impose a
heavy load on the engine when adequate
engine power is not available and may shorten engine life. Correct rated frequency and
voltage are supplied only at the proper governed speed. Some connected electrical load
devices may be damaged by incorrect frequency and/or voltage. Only qualified service
technicians should adjust the governed speed.

4.5.10 CHANGING ENGINE OIL
Refer to maintenance performed by authorized service facilities for engine oil and filter change frequencies.
Drain the oil while the engine is still warm from running. This means warm up the engine, shut it down
and drain immediately as follows:
1. Remove OIL DRAIN HOSE from its retaining clip.
2. Loosen and remove OIL DRAIN HOSE CAP.
Drain oil completely into suitable container.
3. When all oil has drained, install and tighten OIL
DRAIN HOSE CAP, and re-install into its retaining
clip.
4. Turn OIL FILTER (Figure 4.2) counterclockwise
and remove. Dispose of old filter.

Figure 4.2 - Oil Filter

INSPECT EXHAUST SYSTEM

Inspect the exhaust system at least once every three
months. Check all exhaust system pipes, mufflers,
clamps, etc. for condition, tightness, leaks, security,
damage.

4.5.8

CHECK FAN BELT

• Inspect fan belts every three months. Replace any
damaged, deteriorated, worn or otherwise defective belt.
• Check fan belt tension. Thumb pressure, exerted
midway between pulleys, should deflect about 3/8
to 3/4 inch. Adjust belt tension as required.

4.5.9

INSPECT ENGINE GOVERNOR

Visually inspect electronic governor.

16 Generac® Power Systems, Inc.

OIL FILTER

5. Apply light coating of new engine oil to seal of new
oil filter. Install FILTER and tighten by hand only.
DO NOT OVERTIGHTEN.
6. Remove OIL FILL CAP. Add recommended oil (see
SPECIFICATIONS). DO NOT FILL ABOVE THE
DIPSTICK “FULL” MARK. Crankcase oil capacity
is 4.0 U.S. quarts (3.8 liters).

Section 4 — Maintenance
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

Figure 4.4 – Setting the Spark Plug Gap
SET PLUG GAP AT 0.5-0.6 mm
(0.020-0.025 inch)

After refilling the crankcase with oil, always
check oil level on dipstick. NEVER OPERATE
ENGINE WITH OIL BELOW THE DIPSTICK
“ADD” MARK.
7. Start engine and check for oil leaks.

4.5.11 CHANGING THE ENGINE AIR CLEANER
To replace the engine air cleaner, (part number
059402), simply remove the air cleaner cover and
replace the air filter making sure it is positioned
properly before reattaching the cover (Figure 4.3).

Figure 4.3 – Engine Air Cleaner
Air Cleaner

4.5.13 COOLANT CHANGE
Every year, have Authorized Service Facility drain,
flush and refill the cooling system. See SPECIFICATIONS (Section 1.10) for cooling system recommendations.

4.6

MISCELLANEOUS MAINTENANCE

4.6.1

CLEANING THE GENERATOR

Keep the generator as clean and as dry as possible.
Dirt and moisture that accumulates on internal generator windings have an adverse effect on insulation
resistance.

(Doors Removed for Clarity)

See the “Scheduled Maintenance,” Section 4.7, for air
cleaner maintenance.

4.5.12 SPARK PLUGS
Reset the spark plug gap or replace the spark plugs
as necessary. See Section 4.7.
1. Clean the area around the base of the spark plugs
to keep dirt and debris out of the engine. Clean by
scraping or washing using a wire brush and commercial solvent. Do not blast the spark plugs to
clean.
2. Remove the spark plugs and check the condition.
Replace the spark plugs if worn or if reuse is
questionable. See the “Scheduled Maintenance,”
Section 4.7, for recommended inspection.
3. Check the spark plug gap using a wire feeler
gauge. Adjust the gap to 0.5-0.6 mm (0.020-0.025
inch) by carefully bending the ground electrode
(Figure 4.4).

Periodically clean generator exterior surfaces. A soft
brush may be used to loosen caked on dirt. Use a
vacuum system or dry, low pressure air to remove
any accumulations of dirt. The generator is housed
inside an all-weather enclosure, clean the enclosure
with a soft, damp cloth or sponge and water. Apply a
coat of automotive type wax once a year to help prevent corrosion.
Once each year, have the generator cleaned and
inspected by an Authorized Service Dealer. That dealer will use dry, low pressure air to clean internal
windings. Parts inside the control console should be
cleaned and inspected at this time as well.
Finally, have the insulation resistance of stator and
rotor windings checked. If insulation resistances are
excessively low, the generator may require drying.

Generac® Power Systems, Inc. 17

Section 4 — Maintenance
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

4.6.2

BATTERY

All lead-acid storage batteries discharge when not in
use. Refer to specific instructions and warnings that
accompany the battery. If such information is not
available, observe the following precautions when
handling a battery:
• DO NOT use jumper cables and a booster battery
to crank or start the generator engine.
• DO NOT recharge a weak battery while it is
installed in the generator. Remove battery from
generator and recharge in a well-ventilated area,
away from fuel vapors, sparks, heat or flames.
• Battery electrolyte fluid is an extremely caustic
sulfuric solution that can cause severe burns. DO
NOT permit fluid to contact eyes, skin, clothing,
painted surfaces, wiring insulation, etc. If any battery fluid is spilled, flush the affected area with
clear water immediately.
• Always wear safety glasses, rubber apron and
gloves when handling a battery.
• Batteries give off explosive hydrogen gas while
charging. The gas can form an explosive mixture
around the battery for several hours after charging.
Any spark, heat or flames can ignite the gas and
cause an explosion which can shatter the battery,
causing blindness or other serious injury.

4.6.3

BATTERY MAINTENANCE

The battery should be inspected per the “Scheduled
Maintenance,” Section 4.7. The following procedure
should be followed for inspection:
1. Inspect the battery posts and cables for tightness
and corrosion. Tighten and clean as necessary.
2. Check the battery fluid level of unsealed batteries
and, if necessary, fill with DISTILLED WATER
ONLY. DO NOT USE TAP WATER IN BATTERIES.
3. Have the state of charge and condition checked.
This should be done with an automotive-type battery hydrometer.

DANGER
Storage batteries give off explosive hydrogen
gas. This gas can form an explosive mixture
around the battery for several hours after
charging. The slightest spark can ignite the gas
and cause an explosion. Such an explosion can
shatter the battery and cause blindness or
other injury. Any area that houses a storage
battery must be properly ventilated. Do not
allow smoking, open flame, sparks or any spark
producing tools or equipment near the battery.

18 Generac® Power Systems, Inc.

Do not use any jumper cables or booster battery to crank and start the generator engine. If
the battery has completely discharged, remove
it from the generator for recharging.

Be sure the AUTO/OFF/MANUAL switch is set to
the OFF position before connecting the battery
cables. If the switch is set to AUTO or MANUAL,
the generator can crank and start as soon as
the battery cables are connected.
Be sure the utility power supply is turned off,
or sparking may occur at the battery posts as
the cables are attached and cause an explosion.

4.6.4

BATTERY REPLACEMENT

When replacing batteries, use the same number and
the type of battery that follows:
BCI Group No.
26/26R

CCA
525 @ 0 deg. F

NOTE:
The BCI number should be located directly
on the battery.

PERIODIC REPLACEMENT PARTS
Part Name
Oil Filter
Radiator Cap
Air Cleaner
Spark Plug

Generac’s Part Number
# 0A45310244
# 046627
# 059402
# 0A45310275

Section 4 — Maintenance
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

4.7

SCHEDULED MAINTENANCE

The following is a recommended maintenance schedule for Generac Guardian small standby and residential generator sets. The established intervals in the schedule are the maximum recommended when the unit is used in an
average service application. They will need to be decreased (performed more frequently) if the unit is used in a
severe application. Use the unit hour meter or calendar time, whichever occurs first, from the previous maintenance interval to determine the next required maintenance interval.

Service Maintenance Interval Information:
The various service maintenance intervals are designated by interval numbers as follows:
1 An early inspection of the generator set to insure it is ready to operate when required and to identify any potential problem areas.
Performed monthly or following each 10 hours of operation of the unit and requires approximately .5 manhours per unit to complete.
This inspection may be performed by the end user providing the following safety steps are taken to prevent
the engine from starting automatically without warning:
To prevent injury, perform the following steps in the order indicated before starting any maintenance:
•
Disable the generator set from starting and/or connecting to the load by setting the control panel
AUTO-OFF-MANUAL switch to the OFF position.
•
Remove the control panel fuse.
•
Turn off utility supply to engine water heater.
•
Turn off the battery charger by turning off utility supply to the transfer switch.
•
Remove the negative battery cable.

The battery charger must be turned off BEFORE removing the battery cable to prevent an over current condition from burning out sensitive control panel components and circuits.
Following all maintenance, reverse these steps to insure the unit is returned to standby setup for normal
operation when required.
2 A break-in service inspection of the generator set to insure it is ready to operate and carry the load when
required, and to identify any potential problem areas.
Performed ONLY ONCE following the first three months or the first 30 hours of operation after purchase of
the unit and requires approximately 2.5 man-hours per unit to complete.
This inspection contains some maintenance tasks which require special tools, equipment, and/or knowledge
to accomplish and should be performed only by an authorized Generac Service Dealer.
3 An operational inspection of the generator set to insure it is ready to operate and carry the load when required,
and to identify any potential problem areas.
Performed semi-annually or following each 50 hours of operation of the unit and requires approximately 1.5
man-hours per unit to complete.
This inspection contains some maintenance tasks which require special tools, equipment, and/or knowledge
to accomplish and should be performed only by an authorized Generac Service Dealer.
4 A mid-level inspection of the generator set to insure it is ready to operate and carry the load when required, and
to identify any potential problem areas.
Performed annually or following each 100 hours of operation of the unit and requires approximately 4.0
man-hours per unit to complete.
This inspection contains some maintenance tasks which require special tools, equipment, and/or knowledge
to accomplish and should be performed only by an authorized Generac Service Dealer.

Generac® Power Systems, Inc. 19

Section 4 — Maintenance
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

Maintenance
Tasks

Level 1
Recommended
to be done
monthly/
10 hrs.

1. Disable the unit from
operating per the first page
warning.
2. Check the engine oil level.
Adjust as necessary.
3. Check the engine coolant
level. Adjust as necessary.
4. Check the engine coolant
thermal protection level.
Correct as necessary.
5. Check the natural gas
delivery system on gas
engine driven units.
Tighten connections as
necessary.
6. Check the air inlets and
outlets for debris. Clean as
necessary.
7. Check the battery
electrolyte level if
accessible. Adjust as
necessary.
8. Check the battery posts,
cables, and charger for
loose connections,
corrosion, and proper
operation. Correct as
necessary.
9. Check the unit wiring for
loose connections,
corrosion, and damage.
Correct as necessary.
10. Check the engine
accessory drive belts for
wear, weather cracking,
and damage. Replace as
necessary.
11. Visually inspect the unit
looking for leaks, wear or
damage, loose connections
or components, and
corrosion. Correct as
necessary.
12. Test the engine and
transfer switch safety
devices. Correct and/or
adjust as necessary.

20 Generac® Power Systems, Inc.

Level 2
Task
Comp.
(DateInitials)

Required
to be done
3 months/
Break-in
30 hrs.

Level 3
Task
Comp.
(DateInitials)

Required
to be done
Semiannually/
50 hrs.

Level 4
Task
Comp.
(DateInitials)

Required
to be done
Annually/
100 hrs.

Task
Comp.
(DateInitials)

Section 4 — Maintenance
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

Maintenance
Tasks

Level 1
Recommended
to be done
monthly/
10 hrs.

Level 2
Task
Comp.
(DateInitials)

Required
to be done
3 months/
Break-in
30 hrs.

Level 3
Task
Comp.
(DateInitials)

Required
to be done
Semiannually/
50 hrs.

Level 4
Task
Comp.
(DateInitials)

Required
to be done
Annually/
100 hrs.

Task
Comp.
(DateInitials)

13. Initiate an automatic start
and transfer of the unit to
site load and exercise it for
at least 1 hour looking for
leaks, loose connections
or components, and
abnormal operating
conditions. Correct as
necessary.
14. Start and exercise the unit
at full rated load (use a
load bank if the site load is
not enough) for at least 2
hours looking for leaks,
loose connections or
components, and abnormal
operating conditions.
Correct as necessary.
15. Change the engine oil.
16. Replace the engine oil
filter(s).
17. Replace the engine air
filter(s).
18. Check the engine spark
plugs on gas engine driven
units. Clean and re-gap or
replace as necessary.
19. Perform a 5 minute no-load
operational run of the unit
looking for any post service
problems.
20. Return the unit to standby
setup for operation when
required.

Generac® Power Systems, Inc. 21

Section 5 — Troubleshooting
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

5.1

TROUBLESHOOTING POINTS

PROBLEM

CAUSE

CORRECTION

Engine won’t crank.

1. 15 amp fuse blown.
2. Loose or corroded or defective
battery cables.
3. Defective starter contactor.
4. Defective starter motor.
5. Dead or Defective Battery.

1. Replace fuse.
2. Tighten, clean or replace
battery cables as necessary.
3. Replace contactor.
4. Replace starter motor.
5. Remove, change or replace battery.

Engine cranks but won't start

1. Out of fuel.
2. Fuel solenoid (FS) is defective
3. Open Wire #14 from Engine Control
circuit board.
4. Spark plugs defective.

1. Replenish fuel.
2. Replace solenoid.
3. Reconnect wire.

1. Flame arrestor (air cleaner) plugged or
damaged.
2. Plugged fuel line.
3. Defective spark plugs.

1. Clean or replace as needed.

Engine starts then shuts down.

1.
2.
3.
4.
5.
6.
7.

AUTO/OFF/MANUAL Switch at OFF,
engine continues to run

1. Defective AUTO/OFF/MANUAL switch
2. Open/disconnected wire #15A between
AUTO/OFF/MANUAL switch and Control
Module circuit board.
3. Defective Control Module circuit board

1. Replace switch.
2. Reconnect/close wire.

1.
2.
3.
4.

Engine starts hard, runs rough.

No AC output from generator.

Engine oil level is low.
Engine is overheated.
Defective Low Oil Pressure Switch
Defective Coolant Temperature Switch
Defective Control Module circuit board.
Coolant Level is Low.
Defective Low Coolant Level Switch

Check main line circuit breaker.
Check circuit breaker & fuses.
Transfer switch set to NORMAL position
Generator internal failure.

5. Thermal circuit breaker open.

22 Generac® Power Systems, Inc.

4. Clean, regap or replace plugs.

2. Unclog fuel line.
3. Clean, regap or replace plugs.
Check oil and add oil as needed.
Check cooling system for leaks.
Replace switch.
Replace switch.
Replace board.
Repair leak - Add coolant.
Replace Switch.

3. Replace board.
Reset to ON or CLOSED.
Reset and replace, if necessary.
Set to GENERATOR position.
Contact an Authorized Generac
facility.
5. Auto-reset - Wait five min. and
attempt restart.

Section 6 — Notes
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

Generac® Power Systems, Inc. 23

Section 6 — Notes
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

24 Generac® Power Systems, Inc.

Section 7 - Installation Diagram
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Drawing No. 0E1533-A

Generac® Power Systems, Inc. 25

(BLACK)

(BLUE)
(RED)

BLUE

178

225A

239

178

225

BLUE

225A

15A

178
239
183

TR1

YELLOW

15C

BLUE

183

162

CB2

162

BLACK
BLACK

15C

0
4

15E

AS -

FO
SW

194

S16

23
85

TS2

CAP

229
14

229

S16

S15

SUPRESSION ASSEMBLY

FUSE 15 AMPS

56
56

BLUE

85
85
85

TERMINAL STRIP 7 POS.
VOLTAGE REGULATOR

SET EXERCISE SWITCH

VR -

TS1

HOUR METER

229

TS3 -

SW2 -

150

4
4

14
14

176

LEDGEND
FAULT LIGHT

NEUTRAL BLOCK

FL -

4 4

229
176

0
0

17 18

14
4

T2
T1

RED

15 16

FIELD BREAKER

CAPACITOR

178
183

15C

12 13

TRANSFER SWITCH
CONNECTION

183
178

15E

178

6 7 8 9 10

ALTERNATOR STATOR

2 3 4

BLACK

225A

0
0

2 3 4

183

SW2

178

S15
S16

RED

229
56

26 Generac® Power Systems, Inc.

PCB

56
0

BLACK

TS1

RED

GCU

BLUE

S16

YELLOW
BROWN
BLACK

S16

22
2

240.

E1 TO 00
120V.
E2 TO 00

E1 TO E2

OUTPUT CONNECTION
120/240V. 1- PHASE

BRUSH HOLDER
MOUNTING SCREW

CB1

BLUE

CLOSEST TO BEARING

S16

S15
S15

TO GOVERNOR
ACTUATOR

BLUE
BLUE

Section 8 - Electrical Data

Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Wiring Diagram — Control Panel —Drawing No. 0E0345

Section 8 - Electrical Data
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Wiring Diagram — 1.5L Engine — Drawing No. 0E0343-B

Generac® Power Systems, Inc. 27

28 Generac® Power Systems, Inc.

CB1

RED

CB2

14
0
56

229

162

RED

229

RED
BLACK

BLUE
BLUE

S15

S16

PCB

239

RED

178

176

15E

225A

SW1

TO
GOV
ACTUATOR

194

E
4
3
15

15C

239

10
12

178

183

15C

176

225A

RED

TS2

183

178

2 WIRE
START
FOR STANDARD
GENERAC TRANSFER
SWITCH CONNECTION

225

(BLUE)

(BLACK) (BLACK)

N1A

(RED)

ALTERNATE TR1

USE BLUE WIRE FOR 240V L-L SYSTEMS
YELLOW WIRE FOR 208V L-L SYSTEMS
INSULATE UNUSED WIRE

176

23 194

YELLOW

194

BLACK

TR1

PREPACKAGE
TRANSFER SWITCH
CONNECTION TS3

BLUE

BLACK

15C

N.C.

T1 T2

BLUE

SW2

SHOWN IN
OFF POSITION

15C

15A

15A
15C

15A

GCU - GOVERNOR CONTROL UNIT
HM - HOURMETER
PCB - CIRCUIT BOARD CONTROLLER
SA - SUPRESSION ASSEMBLY
SW1 - AUTO/OFF/MANUAL SWITCH
SW2 - SET EXERCISE SWITCH
TR1 -TRANSFORMER, UTILITY SENSING
TS1,2,3 - TERMINAL BOARDS
VR - VOLTAGE REGULATOR

BROWN
BLACK

ORANGE
YELLOW

229

LEGEND

GCU

AR - ALTERNATOR ROTOR
AS - ALTERNATOR STATOR
CAP - CAPACITOR
CB1,2 - CIRCUIT BREAKERS
DPE - EXCITATION WINDING
EC - ENGINE CONNECTION
F - FUSE 15 AMPS
F1 - FUSE 7.5 AMPS IN LINE
FL - LIGHT FAULT INDICATOR

S16

1
5

S15

162

S15

BLACK

DPE

TS1-14

RED

CUSTOMER CONNECTION
120/240V 1-PHASE

EC-3
EC-4
EC-5

EC-9
EC-10
EC-11
EC-12
EC-7
EC-8
EC-6

CAP

Section 8 - Electrical Data

Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Wiring Diagram — 1.5L Guardian — Drawing No. 0E1525

Section 8 - Electrical Data
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Electrical Schematic — 1.5L — Drawing No. 0A7182-C

Generac® Power Systems, Inc. 29

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Governor Assembly — Drawing No. 0E1331-B

5
4
3
ITEM (13) NEOPRENE
COATING

2
1

6
7

WIRE HARNESS
15

12
9

7
16

"A"

17
TO "A"

CARBURETOR ARM
(REF.)

INTAKE MANIFOLD
(REF.)

ITEM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

PART NO.
098290
098941A
098958A
098942A
098225
043146
022097
084543A
098783
037398
0E1326
0A7106
074031
029333A
022507
022473
064526
0E1694

QTY.
1
1
REF
1
2
3
5
1
1
2
1
1
AR
10
2
2
1
1

DESCRIPTION
ASM MOTOR STEPPER
HOUSING GOVERNOR CONNECTOR
CONNECTOR INTERFACE ASSEMBLY
COVER CONNECTOR HOUSING
SCREW FHM #2 X 5/8 SELF TAP
SCREW HHC M6-1.0 X 10 G8.8
WASHER LOCK M6-1/4
SCREW PHM M3-0.5 X 12MM
LEVER STEPPER MOTOR
NUT LOCK HEX #10-32 NYL INS
ASSY. CARBURETOR LINKAGE ROD
BRACKET STEPPER MOTOR
LIQUID NEOPRENE
TIE WRAP 7.4"X.19" BLK UL
SCREW HHC 1/4-20 X 1/2 G5
WASHER FLAT 1/4 ZINC
SCREW TAP HWH #6-25 X 3/8 ZINC
SPRING,ANTI LASH

30 Generac® Power Systems, Inc.

SECURE WIRE HARNESS
WITH TIE WRAP AS SHOWN.

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Mounting Base — Drawing No. 0E0768-B

8
7
6
14

7
6

4
9

15
20

5
7
6

2
3
9
10
22
1

ITEM
1
2
3
4
5
6
7
8
9
10
11
13
14
15
16
17
18
19
20
21
22

PART NO.
0D8656
027482
070936
070936C
039253
022145
022129
045771
071956
051730
021991
0D9335
0D9336
0C2454
047411
022097
022473
055414
049813
026850
0A1694

QTY.
1
2
2
2
8
12
16
4
4
4
1
2
2
16
1
1
1
1
5
1
2

DESCRIPTION
BASE MOUNTING 1.5L STNRD & ACSTC
WASHER SHAKEPROOF EXT 5/16 STL
DAMPENER VIBRATION
VIB. ISO. 70-75 DURO
SCREW HHC M8-1.25 X 20 G8.8
WASHER FLAT 5/16 ZINC
WASHER LOCK M8-5/16
NUT HEX M8-1.25 G8 YEL CHR
WASHER FLAT M8
SCREW HHC M8-1.25 X 60 G8.8
EARTH STRAP
PANEL SUPPORT
PANEL BRACKET
SCREW TH-FRM M6-1 X 16 N WA Z/JS
SCREW HHC M6-1.0 X 16 G8.8
WASHER LOCK M6-1/4
WASHER FLAT 1/4-M6 ZINC
LUG SLDLSS #2-#8 X 17/64 CU
NUT HEX M6 X 1.0 G8 YEL CHR
WASHER SHAKEPROOF EXT 1/4 STL
1-1/2" BUTTON PLUG
Generac® Power Systems, Inc. 31

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW and 20 kW Generators
Standard Compartment — Drawing No. 0E0771-F

WELD STUD UNDER ROOF
PANEL FOR ACCESS
COVER CABLE

1
11
28
13
14

16
11

15
"Y"
26
10

29
22
23
20

26
17
18

11
15

8
24

17
10

25 2

3
17

10
25

32 Generac® Power Systems, Inc.

NOTE:
USE DOOR LATCH
FASTENER TO SECURE
GROUND WIRE.

NOTE:
USE LOCTITE ON
NUTS ITEM #26.

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW and 20 kW Generators
Standard Compartment — Drawing No. 0E0771-F

ITEM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30 *
31 *

PART NO.
0D8666
0D8664C
0D8657
0D8660
0A7568
0D8659
0D8662
0D8661
0D8658
067042
0C2454
033530
051716
022152
0912970064
023762
0912970063
022264
067035
022127
0C2634A
022473
022097
0D2023
0F3390
037337
0D2023
0D8664A
0D8664B
0F1563
0C2634

QTY.
1
1
1
2
2
1
1
1
1
2
40
3
3
3
3
3
3
6
6
1
1
1
1
3
1
6
21
1
1
1
1

* I/N'S 30 & 31 PART OF I/N 21.

Generac® Power Systems, Inc. 33

34 Generac® Power Systems, Inc.

3
34

3
35

13
14

4
10

"Y"
"Y"

22
23

3
11

4
48

STATES FOAM IS ON FAR SIDE

STATES FOAM IS ON NEAR SIDE

NOTE:
USE DOOR LATCH

NOTE:
USE LOCTITE ON
NUT #037337.

TYPICAL OF FRONT DUCT & ROOF
PANEL. SECURE AS SHOWN.

WELD STUD UNDER ROOF
FOR ACCESS COVER CABLE

Section 9 - Exploded Views and Parts

Guardian Liquid-cooled 25 kW Generators
Acoustic Compartment — Drawing No. 0E0772-H

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 25 kW Generators
Acoustic Compartment — Drawing No. 0E0772-H

ITEM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
45
46
47
48
49 *
50 *

PART NO.
0D8666
0D8664C
0D8657
0D8660
0A7568
0D8659
0D8662
0D8661
0D8658
067042
0C2454
033530
051716
022152
0912970064
023762
0912970063
022264
067035
078115
0C2634A
022473
022097
022127
0D8663
0D8665
0E0072D
0E0072B
0E0072Q
0E0072C
0E0072A
0E0072M
0E0072P
0E0072L
0E0072N
0E0072G
0E0072J
0E0072F
0E0072E
0E0072K
0E0072H
0D2023
0F3390
037337
0D8664A
0D8664B
0E0072R
0F1563
0C2634

QTY.
1
1
1
2
2
1
1
1
1
2
40
3
3
3
3
3
3
6
6
13
1
9
9
9
2
2
1
1
2
1
1
2
2
2
2
2
2
1
1
2
2
3
1
6
1
1
2
1
1

DESCRIPTION
ROOF ACSTC & STND CMPRTMNT 1.5L
DUCT CENTER 1.5L
SUPPORT RADIATOR 1.5L MITSU
BRACE SIDE 1.5L MITSU
DOOR WELDMENT 1.5 EPS
CORNER POST REAR RH SIDE 1.5L
DOOR REAR COMPARTMENT 1.5L
BRACE REAR 1.5L MITSU
CORNER POST REAR LH SIDE 1.5L
LATCH & CAM
SCREW TH-FRM M6-1 X 16 N WA Z/JS
SCREW PHM #10-32 X 5/8 ZINC
NUT HEX M5-0.8 G8 YEL CHR
WASHER LOCK #10
ASSEMBLY BASE-DOOR GROUND WIRE
WASHER SHAKEPROOF EXT #10 STL
GRD WIRE ASS'Y 99HSB
WASHER LOCK #8-M4
SCREW PPHM #8-32 X 5/16
WASHER SELF LOCKING DOME
ASSEMBLY COVER ACCESS
WASHER FLAT 1/4 ZINC
WASHER LOCK M6-1/4
NUT HEX 1/4-20 STEEL
BAFFLE CNTRL PNL 1.5L ACOUSTIC
BAFFLE DOOR 1.5L ACOUSTIC UNIT
ACSTC INSLTN 1.5L DUCT RH PNL
ACSTC INSLTN 1.5L DUCT LH PNL
ACSTC INSLTN 1.5L RAD SUPPORT
ACSTC INSLTN 1.5L DUCT FNT PNL
ACSTC INSLTN 1.5L ROOF PANEL
ACSTC INSLTN 1.5L SIDE DR PNL
ACSTC INSLTN 1.5L SIDE DR PNL
ACSTC INSLTN 1.5L SIDE BRC PNL
ACSTC INSLTN 1.5L DR BAFFLE PL
ACSTC INSLTN 1.5L RR CRNR TOP
ACSTC INSLTN 1.5L RR CRNR BOTT
ACSTC INSLTN 1.5L REAR DR PNL
ACSTC INSLTN 1.5L REAR BRC PNL
ACSTC INSLTN 1.5L BAFFLE PANEL
ACSTC INSLTN 1.5L CNTRL SUPPT
GASKET CLIP-ON SELF GRIPPING
LATCH AND CAM
NUT HEX JAM 3/8-24 SS
DUCT LH SIDE 1.5L
DUCT RH SIDE 1.5L
INSUL ACO 1.5L DUCT FRNT PNL
O-RING 5.737 X 5.943
COVER ACCESS GEN 2000

* I/N'S 49 & 50 PART OF I/N 21.

Generac® Power Systems, Inc. 35

Section 9 - Exploded Views and Parts

27
25

TO 'A'

36 Generac® Power Systems, Inc.

'A'

Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Control Panel — Drawing No. 0E0778-G

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Control Panel — Drawing No. 0E0778-G

ITEM

PART NO.

QTY.

1
2
3

0D9322
0D9332
0D9325A

1
1
1

4
5
6
7
8
9
10
11
12
13
14 *

0D9330
0C1457
064009
032300
022676
0E4494
082573
083048
083264
076009A
0E0331

1
1
1
1
1
1
1
1
1
1
1

15
16
17
18
19
20
21
22
23
24
25
26
27
28
29

056739
049350
047822
048766
057335
098647
0E1454
0E1459
072566
080882
0A8955
022097
022473
0C2212
023762

1
1
1
1
1
1
1
1
4
4
2
3
2
10
2

DESCRIPTION
PANEL BACK & BOTTOM GUARDIAN
PANEL LH SIDE GUARDIAN & SPRN
PANEL FRONT CONTROL GUARDIAN
W/ SILKSC
PANEL RH SIDE C-PANEL SML BRK
HOURMETER
LIGHT 12VDC .02A LED RED PILOT
HOLDER FUSE
FUSE 15A X AGC15
SWITCH ROC DPDT ON-OFF-ON
SWITCH ROCKER DPST 125V SPD
ASSEMBLY REGULATOR POTTED
TFMR ASM CMA 240/12V
PP LOGIC ASM 50/60HZ
HARNESS CONTROL PANEL PP
GUARDIAN
RELAY SOLENOID 12VDC PNL MNT
CIRCT BRK 4 X 1 ETA 46-500-P
BLOCK TERM 20A 7 X 6 X 1100V
BLOCK TERM 20A 2 X 6 X 1100V
BLOCK TERM 20A 20 X 6 X 1100V
ASSY L.C. ELECT GOV
DECAL CUST. CONNT. PRE-PACK1.5L
DECAL TERMINAL STRIP PRE-PACK
NUT SPACER.250 PCB
SCREW PPH TAPPING #6 X 5/8 SS
SCREW PHM M6-1.0 X 20MM
WASHER LOCK M6-1/4
WASHER FLAT 1/4-M6 ZINC
SCREW PHTT M4-0.7 X 16 ZYC
WASHER SHAKEPROOF EXT #10
STL

ITEM

PART NO.

QTY.

30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53

0C2267
023897
0C2454
054199
081988
0E2514
0A1354A
074908
020911
051713
049226
051716
036261
0D9334
061979
022237
022241
057073
055440
0D8671
0912970080
049813
033121
026850

14
15
4
1
1
1
1
4
4
5
5
5
4
1
1
1
1
1
1
1
1
1
1
1

54
55
56
57
58

022158
022152
0A3968
0C2323
0E3783

1
1
1
2
1

DESCRIPTION
SCREW HHTT M5-0.8 X 12 BP
WASHER FLAT #10 ZINC
SCREW TH-FRM M6-1X16 N WA Z/JS
DECAL HIGH VOLTAGE
DECAL EXERCISE INFO
STRAIGHT WIRE CONNECTOR 1 1/2"
REGULATOR - DC ALT
SCREW HHTT M5-0.8 X 10 BP
SCREW PPHM M5-0.8 X 30 ZINC
WASHER FLAT M5
WASHER LOCK M5
NUT HEX M5-0.8 G8 YEL CHR
RIVET POP .125 X .129-.133/#30
PANEL, TOP
BUS BAR
WASHER LOCK 3/8
NUT HEX 3/8-16 STEEL
JUNCTION BLOCK 3/8-16
SCREW HHC M5-0.8 X 25 G8.8
HINGE CONTINUOUS 1.5L CNTL PNL
WIRE ASSEMBLY
NUT HEX M6 X 1.0 G8 YEL CHR
SCREW HHC #10-32 X 1/2
WASHER SHAKEPROOF EXT 1/4
STL
NUT HEX #10-32 STEEL
WASHER LOCK #10
CAPACITOR FILTER ASY
SCREW PHTT #6-32 X 5/8 ZYC
DECAL WARNING REMOVE FUSE

* NOT SHOWN

Generac® Power Systems, Inc. 37

38 Generac® Power Systems, Inc.

28
20

73
56

2
7

WATERPUMP
HARDWARE

Section 9 - Exploded Views and Parts

Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Engine — Drawing No. 0E1228-H

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Engine — Drawing No. 0E1228-H

ITEM

PART NO.

QTY.

1
2
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
30
31
32
33
34
35
36
37
38

0A4531
022473
0A45310258
0A4355
0E2632
022097
022507
052212
046526
022131
0C2499
055993
045772
023586
020692
0A7005
052243
0A4772
070901
051735
056768
022145
022129
022259
052213
047411
052830
045771
058306
030795
0A2711A
048665
075885
0A45310257
0E1100
0E0561

1
6
1
1
1
8
2
2
4
20
2
1
1
2
1
2
1
1
2
3
3
12
19
2
11
2
1
12
5
2
1
1
1
1
1
1

39
40
41
42
43

0A6751
034339
026925
061012
039253

1
1
1
1
5

DESCRIPTION
ENGINE-1.5L
WASHER FLAT 1/4 ZINC
GASKET-EXHAUST MANIFOLD
MANIFOLD-EXHAUST
HEAT SHIELD EXH 1.5L
WASHER LOCK M6-1/4
SCREW HHC 1/4-20 X 1/2 G5
SCREW HHC M10-1.25 X 25 G8.8
WASHER-LOCK-M10
WASHER FLAT 3/8 ZINC
STAMPING ENG FOOT
SPACER .41 X .75 X .12 STL/ZNC
NUT HEX M10-1.5 G8 YEL CHR
SCREW SHC 5/16-18 X 2 G8.8 NZ
STARTER-12V
SPACER .56 X 1 X .37 ST/ZNC
SCREW HHC M10-1.5 X 60 G8.8
ENGINE PLATE
SLEEVE DOWEL BLHSG
SCREW HHC M10-1.5 X 70 G8.8
SCREW HHC M10-1.5 X 90 G8.8
WASHER FLAT 5/16 ZINC
WASHER LOCK M8-5/16
NUT HEX 5/16-18 STEEL
SCREW HHC M10-1.25 X 20 G8.8
SCREW HHC M6-1.0 X 16 G8.8
SCREW HHC M10-1.25 X 45 G8.8
NUT HEX M8-1.25 G8 YEL CHR
SCREW SHC M8-1.25 X 25 G12.9
SCREW HHC 5/16-18 X 1 G5
ADAPTER-THERMOSTAT
GASKET THERMOSTAT
THERMOSTAT 195 DEG
GASKET INLET MANIFOLD
MANIFOLD INTAKE MACHINED
ASSY WATER LEVEL SENSOR C/E
PL
SW-TMP 245 DEG 3/8 NPT
BARBED EL 90 3/8 NPT X 5/8
PLUG STD PIPE 3/8 STEEL SQ HD
PLUG STD PIPE 1/8 SCKT HD
SCREW HHC M8-1.25 X 20 G8.8

ITEM

PART NO.

QTY.

44
45
46

0A5110
0A7006
025507

1
1
2

47
48
49
50
51
52
53
54
55
56

022500B
0A8584
036277
042574
026073A
0A6701
039414
0A5568
051769
0A4804

2
1
1
1
1
1
1
1
1
1

0A4804A

0A4800

0A4800A

0A5839
0A1354B
0A4839
055816
0E1936
0A2628
0A5275
0A5586
0A4814
0A45310244
0C1852
0912970066
070928
069860C
069811
058443
0F3856
055934C

1
1
1
4
1
1
1
1
1
1
1
1
1
1
1
2
1
1

57
58
59
60
62
63
64
65
66
67
68
69
70
71
72
73
74 *

DESCRIPTION
PIPE WATER-INLET
O-RING 1-1/16 X 1-5/16 X 1/8
WASHER SHAKEPROOF EXT 7/16
STL
SPACER .41 X .75 X .25 ST/ZNC
SWITCH OIL PRESSURE
ELBOW 90D STREET 1/8
ADAPTOR 1/8 NPTF TO 1/8-28
PLUG STD PIPE 1/4 STEEL SQ HD
SCREW HHC M10-1.5 X 110 G8.8
SCREW HHC M8-1.25 X 35 G8.8
SCREW HHC M12-1.25 X 55 G8.8
WASHER LOCK M12
PULLEY-CRANKSHAFT (1800 RPM)
BUILT PRIOR TO 11/20/02
PULLEY-CRANKSHAFT (1800 RPM)
BUILT AFTER 11/20/02
PULLEY-CRANKSHAFT (3600 RPM)
BUILT PRIOR TO 11/20/02
PULLEY-CRANKSHAFT (3600 RPM)
BUILT AFTER 11/20/02
BRACKET - ALT SUPPRT
DC ALTERNATOR-12V
ARM ADJUST ALTERNATOR
SCREW HHC M6-1.0 X 70 G8.8
FAN COOLING 15"
PULLEY - FAN 95 DIA
V-BELT 3/8 X 32-1/8 1.5L
V-BELT 3/8 X 28.9 1.5L
SPACER PULLEY
FILTER OIL
ADAPTER DRAIN OIL
GROUND WIRE (STARTER)
CLAMP HOSE - OIL DRAIN
HOSE ASM.-OIL DRAIN
CAP HEX 1/4NPT BRASS
CLAMP VINYL .5 X .406 Z
GUARD CRANKSHAFT 1.5L
CLAMP VINYL .5 X .406 Z

* CLAMP FOR WIRING HARNESS (NOT SHOWN)

Generac® Power Systems, Inc. 39

40 Generac® Power Systems, Inc.

"A"

(BOTTOM ONLY)

23
26

8
8

3
14

TO THERMOSTAT
ADAPTER

WATER INLET
TUBE (ON BLOCK)

TO WATER INLET
(MIDWAY UP ENGINE BLOCK)

TO ENGINE BYPASS

Section 9 - Exploded Views and Parts

Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Radiator — Drawing No. 0E0769-J

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Radiator — Drawing No. 0E0769-J

ITEM
1
2
3
4*
5
6
7
8
9
10
11
12
13
14
15
16
17 *
18
19
20
21
22
23
24
26
27
28
29
30
31
32
33
34
35

PART NO.
0D8657
0A5734
0A6237
0A6238
084918
051520N
048031C
099502
083709
052250
047411
022097
049813
022473
084427
051520Z
058443
056892
0A6284
0A6258
029032
031669
060035
022127
046627
0C7649
0C2454
076749
0E0726
035461
0A7275
0A2111
065852
047290A

QTY.
1
1
1
1
1
1
4
4
1
2
4
8
2
9
1
1
6
4
1
1
1
4
4
4
1
1
4
1
1
1
3
2
2
1

DESCRIPTION
SUPPORT RADIATOR 1.5L MITSU
RADIATOR 1.5L
VENTURI 1.5L MODINE
GUARD FAN 1.5L MODINE
HEATER ENGINE 0500W 120V
TUBING 5/8 ID X 12
CLAMP HOSE BAND 1/4
CLAMP HOSE #24 B1.06 - 2.00
CLAMP WIRE HOSE .573 - .551
TAPE FOAM 1 X 1 (12" LG)
SCREW HHC M6-1.0 X 16 G8.8
WASHER LOCK M6-1/4
NUT HEX M6 X 1.0 G8 YEL CHR
WASHER FLAT 1/4 ZINC
BRACKET HEATER
TUBING 5/8 ID X 18"LG
SCREW CRIMPTITE 1/4-20 X 5/8
SCREW CRIMPTITE 10-24 X 3/8
HOSE - LOWER RADIATR
HOSE - UPPER RADIATR
HOSE 9/32 ID (36" LG)
BOLT CARR 1/4-20 X 1-3/4 JS500
SPACER .41 X .75 X .87 ST/ZNC
NUT HEX 1/4-20 STEEL
CAP RADIATOR
CLAMP HOSE .38-.87
SCREW TH-FRM M6-1 X 16 N WA Z/JS
TANK COOLANT RECOVERY
BRACKET WATER BOTTLE 1.5L MIT
BARBED STR 1/4 NPT X 3/8
FOAM 1.5 X 1 ADH BAK
SCREW SWAGE 10-32 X 5/16 Z/YC
SPRING CLIP HOLDER .37-.62
ASSY. RAD. DRAIN HOSE

* FAN GUARD KIT 0E3596 (NOT USED WITH LEVEL ONE GUARDING)

Generac® Power Systems, Inc. 41

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Fuel System — Drawing No. 0E0774-F

18
13

24
25

"C"

16
29

"C"

14
30

36 37 35

32
33

38
39

40
1

6
28
PORT
"OUT 1"
(NATURAL GAS)

43
9

"D"

40
41
PORT
"OUT 2"

6
2

15
11
4

L.P. VAPOR
42 Generac® Power Systems, Inc.

"D"

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Fuel System — Drawing No. 0E0774-F

ITEM

PART NO.

1*
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16 **
17
18
19
20
21 **
22 **
23
24
25
26
27
28
29
30 **
31 **
32 **
33 **
34 **
35 **
36 **
37 **
38 **
39 **
40
41
42
43
44

--------075580
0E1006
039253
022145
022129
045771
0A7040
032552
029032
0E1056
029032
0A5547
048031C
0D1509
0E0591
059402
037561
0E1028
059401
091526
049226
026307
062522
022127
022259
050279
0A6125
0D8492T
0E1104
0E0668
0E0590
0C5133
0E0665
0E1108
033138
022152
0E0645
063463A
0E1558
057823
0E1111
042907
0C2454

QTY.
1
1
1
2
2
6
2
1
1
1
1
1
1
4
1
1
1
1
1
1
4
4
1
1
1
2
1
2
1
1
1
1
1
1
1
1
1
1
1
1
2
1
2
2

DESCRIPTION
WELDMENT MOUNTING BASE
FLANGE FUEL INLET
ASSY REGULATOR 1.5L N.G.OR LPV
SCREW HHC M8-1.25 X 20 G8.8
WASHER FLAT 5/16 ZINC
WASHER LOCK M8-5/16
NUT HEX M8-1.25 G8 YEL CHR
BRACKET-RAD HOSE
BARBED EL 90 5/16 X 1/8 NPT
HOSE 9/32 ID 11"
FUEL HOSE ASSM. NAT.GAS/L.P.V.
HOSE 9/32 ID 7.5"
COVER AIR CLEANER
CLAMP HOSE BAND 1/4
DECAL INLET PRESSURE
ADAPTER,CARB.TO AIR CLNR
FILTER ELEMENT
NUT WING 1/4-20 NYLK
CARBURETOR ASSY. 1.5L
CARBURETOR GASKET
SCREW PPHM M5-0.8 X 12 ZNC
WASHER LOCK M5
ELBOW 90D STREET 3/4
STUD TH 1/4-20 X 3 G2 ZNC FULL
NUT HEX 1/4-20 STEEL
NUT HEX 5/16-18 STEEL
DECAL FUEL INLET NG
STUD 5/16-18 X 1.25 F THR
DECAL EMISSION CTRL 1.5 NG 2005 (10-15KW NATURAL GAS)
GASKET AIR CLEANER ADAPTER
O-RING 2-028 1.38 X 1.50 X .06
VENTURI 18MM
O-RING 29.82 X 2.62
SCREW THROTTLE PIN STOP
THROTTLE ARM REWORK
SCREW HHM #10-32 X 5/8
WASHER LOCK #10
LEVER THROTTLE STOP
BARBED STR 3/8NPT X 1/2 W/VS
HOSE LPG & NAT GAS 1/2 ID (23"LG)
CLAMP HOSE #10 .56 - 1.06
PLATE, GAS REGULATOR MOUNTING
SCREW HHC M8-1.25 X 16 G8.8
SCREW TH-FRM M6-1 X 16 N WA Z/JS

* SHOWN IN OTHER VIEW
** INCLUDED IN ITEM 19 (CARBURETOR ASY. )

Generac® Power Systems, Inc. 43

Section 9 - Exploded Views and Parts

14
15

To Blower
Housing

To Engine
Crankshaft

Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Alternator — Drawing No. 0A9348-G

44 Generac® Power Systems, Inc.

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Alternator — Drawing No. 0A9348-G

ITEM
1

2
3
4
5
6
7
8

9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
26 *
27
28
29
30
31
32
33
35
36

PART NO.
098671
098681
098675
098936
0A5336A
0A1659
071912
049226
051713
022129
098672
098673
098674
098682
098683
098684
098676
098677
098678
097620
098937
097621
0A5382
075591
075476
0A5601A
075554B
0A9375
022152
097146
042558
0A5061
0A4989
053557
051769
049541
046526
045772
087599
077043E
022131
072578
0A7043
049808
058589
023365
0A8830
072080

QTY.
1
1
1
1
1
1
4
4
4
4
1
1
1
1
1
1
1
1
1
1
1
1
1
1
4
1
4
4
4
1
1
1
1
1
6
4
4
4
1
1
4
1
5
5
1
4
4
1

DESCRIPTION
ASSY ROTOR 10KW
ASSY ROTOR 15KW
ASSY ROTOR 20KW
ASSY ROTOR 25KW
HOUSING BLOWER
SCREEN AIR OUTLET
SCREW PPHM M5-0.8 X 8 SS
WASHER LOCK M5
WASHER FLAT M5
WASHER LOCK M8-5/16
ASSY STATOR 10KW A
ASSY STATOR 10KW D
ASSY STATOR 10KW GJK
ASSY STATOR 15KW 1PH A
ASSY STATOR 15KW 3PH D
ASSY STATOR 15KW 1PH GJK
ASSY STATOR 20KW 1PH A
ASSY STATOR 20KW 1PH D
ASSY STATOR 20KW 1PH GJK
ASSY STATOR 25KW 1PH A
ASSY STATOR 25KW 1PH D
ASSY STATOR 25KW 3PH D
BEARING CARRIER REAR
ASSY HOLDER BRUSH
SCREW PPHM M4-0.7 X 16
COVER REAR BEARING
BOLT STATOR X 16" LG
SCREW RHM #10-24 X 2
WASHER LOCK #10
FAN & RING GEAR ASSEM.
KEY SQ 3/8 X 1 STEEL
SPACER-FLEX PLATE
PLATE FLEX
SCREW HHC M12-1.75 X 40 G8.8
WASHER LOCK M12
SCREW HHC M10-1.5 X 35 G8.8
WASHER LOCK M10
NUT HEX M10-1.5 G8 YEL CHR
PLUG PLASTIC 3/8 NPT
FLEX CONDUIT 1" BLACK (NOT SHOWN)
WASHER FLAT 3/8-M10 ZINC
SPACER ROTOR SHAFT
SCREW HHC M12-1.25 X 25 G8.8
WASHER FLAT M12
DECAL WARN ENG START
WASHER SHAKEPROOF INT #8
WASHER FLAT .34 ID X .75 OD
DECAL DANGER STANBY UNITS

* USED ON PRE-PACKAGED UNITS ONLY

Generac® Power Systems, Inc. 45

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Battery — Drawing No. 0E0770-B

STARTER
SOLENOID

4
14

1
TO ENGINE
BLOCK

16
6

15
ITEM
1
2
3
4
5
6
7
8
9
13
14
15
16
17

PART NO.
077483
038804D
038805B
0742600131
022131
046526
052213
075763
0D8668
050331A
050331
0C2454
025507
027482

QTY.
REF
1
1
1
1
1
1
3
1
1
1
2
1
2

DESCRIPTION
BATT 12VDC 75-AH 26 (NOT INCLUDED)
CABLE BATT RED #4 X 20.00
CABLE BATT BLK #4 X 23.00
ASSY,WIRE#16 RED 1.6
WASHER FLAT 3/8 ZINC
WASHER LOCK M10
SCREW HHC M10-1.25 X 20 G8.8
BOOT, BATTERY CABLE
BRACKET, BATTERY HOLD DOWN 1.5
BATTERY POST COVER (RED+)
BATTERY POSTCOVER (BLACK-)
SCREW TH-FRM M6-1X16 N WA Z/JS
WASHER SHAKEPROOF EXT 7/16 STL
WASHER SHAKEPROOF EXT 5/16 STL

46 Generac® Power Systems, Inc.

Section 9 - Exploded Views and Parts
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
Muffler — Drawing No. 0E0773-A

10
9

14
8
15

12
13
9
3
7

3
5

ITEM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

PART NO.
0A4355
0E2844
036434
036449
0E0109
0C1318
0D8657
0E0170
0D9437
060366
039253
022145
022129
045771
0A8974
027837

QTY.
1
1
3
3
1
1
1
1
1
2
4
4
4
4
1
2

DESCRIPTION
MANIFOLD EXHAUST 1.5L
NIPPLE TOE 1.5NPTX5.5 BLK IRON
BOLT U 5/16-18 X 2.09
SADDLE 2 INCH
PIPE,EXHAUST 1.5L STNDRD&ACSTC
FLEX PIPE EXHAUST
SUPPORT, RADIATOR 1.5L MITSU
BLANKET, EXHAUST 1.5L MITSU
MUFFLER,1.5L ACOUSTIC&STANDARD
STRAP MUFFLER 6" DIA
SCREW HHC M8-1.25 X 20 G8.8
WASHER FLAT 5/16 ZINC
WASHER LOCK M8-5/16
NUT HEX M8-1.25 G8 YEL CHR
CAP RAIN 2"
SCREW RHM 1/4-20 X 2-1/4
Generac® Power Systems, Inc. 47

Section 10 – Warranty
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

CALIFORNIA EMISSION CONTROL WARRANTY STATEMENT
YOUR WARRANTY RIGHTS AND OBLIGATIONS
The California Air Resources Board (CARB) and Generac Power Systems, Inc. (Generac) are pleased to explain the Emission
Control System Warranty on your new engine.* In California, new utility, and lawn and garden equipment engines must be
designed, built and equipped to meet the state’s stringent anti-smog standards. Generac will warrant the emission control
system on your engine for the periods of time listed below provided there has been no abuse, neglect, unapproved modification or improper maintenance of your engine.
Your emission control system may include parts such as the carburetor, ignition system and exhaust system. Generac will
repair your engine at no cost to you for diagnosis, replacement parts and labor, should a warrantable condition occur.

MANUFACTURER’S EMISSION CONTROL SYSTEM WARRANTY COVERAGE:
Emissions control systems on 1995 and later model year engines are warranted for two years as hereinafter noted. If, during such warranty period, any emission-related component or system on your engine is found to be defective in materials or
workmanship, repairs or replacement will be performed by a Generac Authorized Warranty Service Facility.

PURCHASER’S/OWNER’S WARRANTY RESPONSIBILITIES:
As the engine purchaser/owner, you are responsible for the completion of all required maintenance as listed in your factory
supplied Owner’s Manual. For warranty purposes, Generac recommends that you retain all receipts covering maintenance
on your engine. However, Generac cannot deny warranty solely due to the lack of receipts or for your failure to ensure the
completion of all scheduled maintenance.
As the engine purchaser/owner, you should, however, be aware that Generac may deny any and/or all warranty coverage or
responsibility if your engine, or a part/component thereof, has failed due to abuse, neglect , improper maintenance or unapproved modifications, or the use of counterfeit and/or “grey market” parts not made, supplied or approved by Generac.
You are responsible for presenting your engine to a Generac Authorized Warranty Service Facility as soon as a problem occurs. The warranty repairs should be completed in a reasonable amount of time, not to exceed 30 days.
Warranty service can be arranged by contacting either your selling dealer or a Generac Authorized Warranty Service Facility.
To locate the Generac Authorized Warranty Service Facility nearest you, call our toll-free number:

1-800-333-1322
IMPORTANT NOTE: This warranty statement explains your rights and obligations under the Emission Control System
Warranty (ECS Warranty), which is provided to you by Generac pursuant to California law. See also the “Generac Limited
Warranties for Generac Power Systems, Inc.,” which is enclosed herewith on a separate sheet, also provided to you by
Generac. The ECS Warranty applies only to the emission control system of your new engine. If there is any conflict in terms
between the ECS Warranty and the Generac Warranty, the ECS Warranty shall apply except in circumstances where the
Generac Warranty may provide a longer warranty period. Both the ECS Warranty and the Generac Warranty describe important rights and obligations with respect to your new engine.
Warranty service can be performed only by a Generac Authorized Warranty Service Facility. When requesting warranty service, evidence must be presented showing the date of the sale to the original purchaser/owner.
If you have any questions regarding your warranty rights and responsibilities, you should contact Generac at the following address:

ATTENTION WARRANTY DEPARTMENT
GENERAC POWER SYSTEMS, INC.
P.O. BOX 297
WHITEWATER, WI 53190
Part 1

48 Generac® Power Systems, Inc.

Section 10 – Warranty
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

EMISSION CONTROL SYSTEM WARRANTY
Emission Control System Warranty (ECS Warranty) for 1995 and later model year engines:
(a) Applicability: This warranty shall apply to 1995 and later model year engines. The ECS Warranty Period shall begin on
the date the new engine or equipment is purchased by/delivered to its original, end-use purchaser/owner and shall continue for 24 consecutive months thereafter.
(b) General Emissions Warranty Coverage: Generac warrants to the original, end-use purchaser/owner of the new engine or
equipment and to each subsequent purchaser/owner that each of its engines is ...
(1) Designed, built and equipped so as to conform with all applicable regulations adopted by the CARB pursuant to its
authority, and
(2) Free from defects in materials and workmanship which, at any time during the ECS Warranty Period, may cause a warranted emissions-related part to fail to be identical in all material respects to the part as described in the engine manufacturer’s application for certification.
(c) The ECS Warranty only pertains to emissions-related parts on your engine, as follows:
(1) Any warranted, emissions-related parts that are not scheduled for replacement as required maintenance in the Owner’s
Manual shall be warranted for the ECS Warranty Period. If any such part fails during the ECS Warranty Period, it shall
be repaired or replaced by Generac according to Subsection (4) below. Any such part repaired or replaced under the
ECS Warranty shall be warranted for the remainder of the ECS Warranty Period.
(2) Any warranted, emissions-related part that is scheduled only for regular inspection as specified in the Owner’s Manual
shall be warranted for the ECS Warranty Period. A statement in such written instructions to the effect of “repair or
replace as necessary” shall not reduce the ECS Warranty Period. Any such part repaired or replaced under the ECS
Warranty shall be warranted for the remainder of the ECS Warranty Period.
(3) Any warranted, emissions-related part that is scheduled for replacement as required maintenance in the Owner’s
Manual shall be warranted for the period of time prior to the first scheduled replacement point for that part. If the part
fails prior to the first scheduled replacement, the part shall be repaired or replaced by Generac according to Subsection
(4) below. Any such emissions-related part repaired or replaced under the ECS Warranty shall be warranted for the
remainder of the ECS Warranty Period prior to the first scheduled replacement point for such emissions-related part.
(4) Repair or replacement of any warranted, emissions-related part under this ECS Warranty shall be performed at no
charge to the owner at a Generac Authorized Warranty Service Facility.
(5) When the engine is inspected by a Generac Authorized Warranty Service Facility, the owner shall not be held responsible for diagnostic costs if the repair is deemed warrantable.
(6) Generac shall be liable for damages to other original engine components or approved modifications proximately caused
by a failure under warranty of any emission-related part covered by the ECS Warranty.
(7) Throughout the ECS Warranty Period, Generac shall maintain a supply of warranted emission-related parts sufficient
to meet the expected demand for such emission-related parts.
(8) Any Generac authorized and approved emission-related replacement part may be used in the performance of any ECS
Warranty maintenance or repairs and will be provided without charge to the owner. Such use shall not reduce Generac
ECS Warranty obligations.
(9) Unapproved, add-on, modified, counterfeit and/or “grey market” parts may not be used to modify or repair a Generac
engine. Such use voids this ECS Warranty and shall be sufficient grounds for disallowing an ECS Warranty claim.
Generac shall not be held liable hereunder for failures of any warranted parts of a Generac engine caused by the use of
such an unapproved, add-on, modified, counterfeit and/or “grey market” part.

EMISSION RELATED PARTS INCLUDE THE FOLLOWING:
1) Fuel Metering System:
1.2) LPG/Natural Gas carburetion assembly and its internal
components.
a) Fuel controller (if so equipped)
b) Mixer and its gaskets (if so equipped)
c) Carburetor and its gaskets (if so equipped)
d) Primary gas regulator (if so equipped)
e) LP liquid vaporizer (if so equipped)
2) Air Induction System including:
a) Intake pipe/manifold
b) Air cleaner

3) Ignition System including:
a) Spark plug
b) Ignition module
4) Catalytic Muffler Assembly (if so equipped) including:
a) Muffler gasket
b) Exhaust manifold
5) Crankcase Breather Assembly including:
a) Breather connection tube

*Generac engine types covered by this warranty statement include the following:
1) Prepackaged Standby Generator
2) Auxiliary Power Unit (APU) Generator
3) Standby Generator
Part 2

Generac® Power Systems, Inc. 49

Section 10 – Warranty
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators

GENERAC POWER SYSTEMS "TWO YEAR" LIMITED WARRANTY FOR GUARDIAN®
"PREPACKAGED EMERGENCY AUTOMATIC STANDBY GENERATORS"
For a period of two years from the date of original sale, Generac Power Systems, Inc. (Generac) warrants that its Guardian generator
will be free from defects in material and workmanship for the items and period set forth below. Generac will, at its option, repair or replace
any part which, upon examination, inspection and testing by Generac or a Guardian Authorized Warranty Service Dealer, is found to be
defective. Any equipment that the purchaser/owner claims to be defective must be examined by the nearest Guardian Authorized
Warranty Service Dealer. All transportation costs under the warranty, including return to the factory, are to be borne and prepaid by the
purchaser/owner. This warranty applies only to Generac Guardian prepackaged emergency automatic standby generators sold and
rated for use in "Standby" applications.

WARRANTY SCHEDULE

YEARS ONE and TWO - 100% (one hundred percent) transferable coverage on Labor and Part(s) listed (proof of purchase and maintenance is required):
Engine - All Components
Alternator - All Components
Transfer System - All Components
Steel enclosures are warranted against rusting for the first year of ownership only. Damage caused after receipt of generator is the
responsibility of the owner and is not covered by this warranty. Nicks, scrapes, dents or scratches to the painted enclosure should be
repaired promptly by the owner.
All warranty expense allowances are subject to the conditions defined in Guardian's Warranty Policies, Procedures and Flat Rate
Manual.

THIS WARRANTY SHALL NOT APPLY TO THE FOLLOWING:

• Guardian generators that utilize non-Guardian/Generac replacement parts.
• Guardian generators utilizing non-Guardian/Generac automatic transfer switches.
• Repairs or diagnostics performed by individuals other than Guardian/Generac authorized dealers not authorized in writing by
Generac Power Systems.
• Any Guardian generators used as rental or trailer mounted applications.
• Units used for prime power in place of existing utility power where utility power is present or in place of utility power where utility
power service does not normally exist.
• Costs of normal maintenance, adjustments, installation and start-up.
• Steel enclosures that are rusting due to the improper installation, location in a harsh or saltwater environment or scratched where
integrity of paint applied is compromised.
• Failures caused by any contaminated fuels, oils, coolants or lack of proper fluid amounts.
• Failures due, but not limited, to normal wear and tear, accident, misuse, abuse, negligence or improper installation. As with all
mechanical devices, the Generac engines need periodic part(s) service and replacement to perform well. This warranty will not
cover repair when normal use has exhausted the life of a part(s) or engine.
• Failures caused by any external cause or act of God, such as collision, theft, vandalism, riot or wars, nuclear holocaust, fire,
freezing, lightning, earthquake, windstorm, hail, volcanic eruption, water or flood, tornado or hurricane.
• Damage related to rodent and/or insect infestation.
• Products that are modified or altered in a manner not authorized by Generac in writing.
• Any incidental, consequential or indirect damages caused by defects in materials or workmanship, or any delay in repair or
replacement of the defective part(s).
• Failure due to misapplication.
• Telephone, cellular phone, facsimile, internet access or other communication expenses.
• Living or travel expenses of person(s) performing service, except as specifically included within the terms of a specific unit warranty
period.
• Expenses related to "customer instruction" or troubleshooting where no manufacturing defect is found.
• Rental equipment used while warranty repairs are being performed.
• Costs incurred for equipment used for removal and/or reinstallation of generator, (i.e.; cranes, hoists, lifts, etc.)
• Overnight freight costs for replacement part(s).
• Overtime labor.
• Starting batteries, fuses, light bulbs and engine fluids.
THIS WARRANTY IS IN PLACE OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED. SPECIFICALLY, GENERAC MAKES
NO OTHER WARRANTIES AS TO THE MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Some states do not
allow limitations on how long an implied warranty lasts, so the above limitation may not apply to you.
GENERAC'S ONLY LIABILITY SHALL BE THE REPAIR OR REPLACEMENT OF PART(S) AS STATED ABOVE. IN NO EVENT
SHALL GENERAC BE LIABLE FOR ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES, EVEN IF SUCH DAMAGES ARE A
DIRECT RESULT OF GENERAC'S NEGLIGENCE. Some states do not allow the exclusion or limitation of incidental or consequential
damages, so the above limitation may not apply to you.
This warranty gives you specific legal rights. You also have other rights from state to state.

GENERAC® POWER SYSTEMS, INC.
P.O. BOX 297 • WHITEWATER, WI 53190
Part No. 0E1151

Revision M (03/22/05)

Revision (02/01/05)

Printed in U.S.A.

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.4
Linearized                      : Yes
Page Count                      : 52
XMP Toolkit                     : XMP toolkit 2.9.1-13, framework 1.6
About                           : uuid:1f0f589f-0297-417a-8ca2-6f24c3823f5f
Producer                        : Acrobat Distiller 6.0 (Windows)
Creator Tool                    : PScript5.dll Version 5.2.2
Modify Date                     : 2005:03:22 11:31:40-06:00
Create Date                     : 2005:03:22 11:31:40-06:00
Document ID                     : uuid:a8470c51-a2de-4080-9db3-dd527c2a4383
Format                          : application/pdf
Title                           : 0E1151RevM.qxd
Creator                         : bpeterso
Author                          : bpeterso

EXIF Metadata provided by EXIF.tools

Generac Power Systems Liquid Cooled Prepackaged Standby Generators 004721 0 004722 004723 004724 004725 1 0E1151RevM

004721-0, 004722-0, 004723-0, 004724-0, 004725-0, 004725-1, 004725-2, 004725-3, 004726-0 to the manual a79844cc-4c63-4c92-beef-bd7bf28dcced

Navigation menu

Versions of this User Manual:

Views

Navigation