Generac 04675-3, 04673-2, 04674-2 User Manual
POWER SYSTEMS, INC.
®
Installation and
Owner’s Manual
Air-cooled Automatic
Standby Generators
Models:
04673-2 (6 kW NG, 7 kW LP)
04674-2 (12 kW NG, 12 kW LP)
04675-3 (13 kW NG, 15 kW LP)
DEADLY EXHAUST FUMES. OUTDOOR INSTALLATION ONLY!!
Not intended for use as Primary Power in place of utility
or in life-support applications.
*This manual should remain with the unit.*
GENERAC
POWER SYSTEMS, INC.
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Generac®Power Systems, Inc.
INTRODUCTION
Thank you for purchasing this model by Generac
Power Systems Inc.. This model is a compact, high
performance, air-cooled, engine-driven generator
designed to automatically supply electrical power to
operate critical loads during a utility power failure.
This unit is factory installed in an all-weather, metal enclosure that is intended exclusively for outdoor installation.
This generator will operate using either vapor withdrawn
liquid propane (LP) or natural gas (NG).
READ THIS MANUAL THOROUGHLY
If any portion of this manual is not understood, contact
the nearest Generac Authorized 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
operation that may be hazardous if performed incorrectly or carelessly. Observe them carefully. Their
definitions are as follows:
After this heading, read instructions that, if not
strictly complied with, will result in serious personal injury, including death, in addition to property
damage.
After this heading, read instructions that, if not
strictly complied with, may result in serious personal injury or property damage.
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.
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.
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.
CONTENTS
This manual contains pertinent owner’s information,
including warranty, electrical diagrams, exploded
views and lists of repair parts, for three different
Guardian models:
• 04673-2 – 6 kW NG, 7 kW LP, single-cylinder GH410 Engine
• 04674-2 – 12 kW NG, 12 kW LP, V-twin GT-990
Engine
• 04675-3 – 13 kW NG, 15 kW LP, V-twin GT-990
Engine
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 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
ensures a minimum number of problems and keep
operating expenses at a minimum. See the Generac
Authorized Dealer for service aids and accessories.
HOW TO OBTAIN SERVICE
When the generator requires servicing or repairs,
simply contact a Generac Authorized Dealer for
assistance. Service technicians are factory-trained
and are capable of handling all service needs.
When contacting a Generac Authorized Dealer about
parts and service, always supply the complete model
number and serial number of the unit as given on its
data decal, which is located on the generator. See
Figure 1.1 or Figure 1.2 in Section 1.4 for decal location.
Model No. ____________ Serial No. ______________
AUTHORIZED
DEALER LOCATION
To locate the nearest GENERAC AUTHORIZED
DEALER, please call this number:
1-800-333-1322
DEALER LOCATION INFORMATION
CAN BE OBTAINED AT THIS NUMBER.
DANGER
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Table of Contents
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
Generac®Power Systems, Inc. 1
Introduction ........................Inside Front Cover
Read This Manual Thoroughly ........................IFC
Contents ..........................................................IFC
Operation and Maintenance ............................IFC
How to Obtain Service ....................................IFC
Authorized Dealer Locator Number ....................IFC
Safety Rules ........................................................2
Standards Index ..................................................3
Section 1 – General Information ..................4
1.1 Unpacking/Inspection ....................................4
1.2 Protection Systems ........................................4
1.3 System Set LED ............................................4
1.4 Your Generator ..............................................5
1.5 Specifications ................................................6
1.5.1 Generator ..........................................6
1.5.2 Engine ................................................6
1.6 Fuel Requirements and Recommendations ....7
1.7 Fuel Consumption ........................................7
1.8 Reconfiguring the Fuel System ......................7
1.8.1 7 kW, 410CC ......................................7
1.8.2 12 kW and 15 kW, 990cc Engines ......7
1.9 Location ........................................................8
1.9.1 Generator ..........................................8
1.9.2 Transfer Switch ..................................8
1.10 Battery Installation ........................................9
1.11 The Battery ....................................................9
Section 2 – Post Installation Start-up
and Adjustments ......................10
2.1 Before Initial Start-up..................................10
2.2 Check Transfer Switch Operation................10
2.3 Electrical Checks ........................................10
2.4 Generator Tests Under Load ......................11
2.5 Checking Automatic Operation ....................11
2.6 Adjusting the Regulator (Natural Gas Only) ..12
2.7 Engine Governor Adjustment ......................12
2.7.1 7 kW Units ......................................12
2.7.2 12 kW and 15 kW Units ..................13
2.7.3 Additional Corrosion Protection ......13
2.8 Voltage Regulator Adjustment ......................13
Section 3 – Operation ....................................14
3.1 Break-in Procedure......................................14
3.2 Using the Auto/Off/Manual Switch ..............14
3.2.1 “Auto” Position ..................................14
3.2.2 “Off” Position....................................14
3.2.3 “Manual” Position ............................14
3.3 Automatic Transfer Operation ....................14
3.4 Sequence of Automatic Operation................14
3.5 Manual Transfer Operation ........................15
3.5.1 Transfer to Generator
Power Source......................................15
3.5.2 Transfer Back to Utility
Power Source......................................15
3.6 Setting the Exercise Timer ..........................16
3.7 Protection Systems ......................................16
3.7.1 Low Oil Pressure Switch ..................16
3.7.2 High Temperature Switch ................16
3.7.3 Overcrank ........................................16
3.7.4 Overspeed ........................................17
Section 4 – Maintenance ..............................17
4.1 Fuse ............................................................17
4.2 Checking the Engine Oil Level ....................17
4.3 Changing the Engine Oil ..............................17
4.3.1 Engine Oil Recommendations ..........17
4.3.2 Oil Change Procedure ......................18
4.4 Changing the Oil Filter ................................18
4.5 Changing the Engine Air Cleaner ................18
4.5.1 7 kW, 12 kW and 15 kW
Generators........................................18
4.6 Spark Plug(s) ..............................................19
4.7 Battery Maintenance....................................19
4.8 Adjusting Valve Clearance ............................20
4.9 Cooling System............................................20
4.10 Attention After Submersion ........................21
4.11 Corrosion Protection ..................................21
4.12 Out of Service Procedure ............................21
4.12.1 Removal From Service......................21
4.12.2 Return to Service..............................21
4.13 Service Schedule ........................................22
Section 5 – Troubleshooting ........................23
5.1 Troubleshooting Guide ................................23
Section 6 – Electrical Data ............................24
Section 7 – Exploded Views and
Parts Lists....................................32
Section 8 – Mounting Dimensions..............50
Section 9 – Notes ............................................51
Section 10 – Warranty....................................52
2 Generac®Power Systems, Inc.
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 anticipate every possible circumstance 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 Generac
does not specifically recommend, ensure that it is
safe for others. Also make sure the procedure, work
method or operating technique chosen does not render the generator unsafe.
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 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.
Please read all hazards carefully!
GENERAL HAZARDS
• For safety reasons, Generac recommends that the
installation, initial start-up and maintenance of
this equipment is carried out by a Generac
Authorized Dealer.
• The engine exhaust fumes contain carbon monox-
ide, which can be DEADLY. This dangerous gas, if
breathed in sufficient concentrations, can cause
unconsciousness or even death. This exhaust system must be installed properly, in strict compliance with applicable codes and standards.
Following installation, do nothing that might render the system unsafe or in noncompliance with
such 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 venti-
lating air is critical to 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. The
generator MUST be installed outdoors.
• When working on this equipment, remain alert at
all times. Never work on the equipment when
physically or mentally fatigued.
• Inspect the generator regularly, and contact the
nearest Generac Authorized Dealer for parts needing repair or replacement.
• Before performing any maintenance on the genera-
tor, 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.
!!!
IMPORTANT SAFETY INSTRUCTIONS
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
SAVE THESE INSTRUCTIONS – The manufacturer suggests that these rules for safe
operation be copied and posted near the unit’s installation site. Safety should be stressed to
all operators and potential operators of this equipment.
!
!
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.
WARNING:
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Generac®Power Systems, Inc. 3
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 does the standby generator when it is in operation. Avoid contact with bare wires, terminals, connections, etc., while the unit is running. 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.
• The National Electrical Code (NEC) requires the
frame and external electrically conductive parts of
the generator to be connected to an approved earth
ground. Local electrical codes also may require
proper grounding of the generator electrical system.
• After installing this home standby electrical system, the generator may crank and start at any time
without warning. When this occurs, load circuits
are transferred to the STANDBY (generator) power
source. To prevent possible injury if such a start
and transfer occur, always set the generator’s
AUTO/OFF/MANUAL switch to its OFF position
before working on equipment and remove the 5A
and 15A fuses from the generator control panel.
• 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 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
• For fire safety, the generator must be installed and
maintained properly. Installation always must
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 in
accordance with the manufacturer’s instructions
and recommendations. Following proper installation, do nothing that might alter a safe installation
and render the unit in noncompliance with the
aforementioned codes, standards, laws and regulations.
• Keep a fire extinguisher near the generator at all
times. Extinguishers rated “ABC” by the National
Fire Protection Association are appropriate for use
on the standby electric system. Keep the extinguisher properly charged and be familiar with its
use. If there are any questions pertaining to fire
extinguishers, consult the local fire department.
EXPL
OSION HAZARDS
• 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.
• Gaseous fluids such as natural gas and liquid
propane (LP) gas are extremely EXPLOSIVE.
Install the fuel supply system according to applicable fuel-gas codes. Before placing the home standby electric system into service, fuel system lines
must be properly purged and leak tested according
to applicable code. After installation, inspect the
fuel system periodically for leaks. No leakage is
permitted.
STANDARDS INDEX
In the absence of pertinent standards, codes, regulations and laws, the published information listed
below may be used as installation guide for this
equipment.
1. NFPA No. 37, STATIONARY COMBUSTION
ENGINES AND GAS TURBINES, available from
the National Fire Protection Association, 470
Atlantic Avenue, Boston, MA 02210.
2. NFPA No. 76A, ESSENTIAL ELECTRICAL SYS-
TEMS FOR HEALTH CARE FACILITIES, available same as Item 1.
3. NFPA No. 54, NATIONAL FUEL GAS CODE,
available same as Item 1.
4. NFPA No. 58, AMERICAN NATIONAL STANDARD
FOR STORAGE AND HANDLING OF LIQUEFIED
PETROLEUM GAS, available same as Item 1.
5. NFPA No. 70, NFPA HANDBOOK OF NATIONAL
ELECTRIC CODE, available same as Item 1.
6. Article X, NATIONAL BUILDING CODE, available
from the American Insurance Association, 85
John Street, New York, N.Y. 10038.
7. AGRICULTURAL WIRING HANDBOOK, available
from the Food and Energy Council, 909
University Avenue, Columbia, MO 65201.
8. ASAE EP-3634, INSTALLATION AND MAINTE-
NANCE OF FARM STANDBY ELECTRICAL SYSTEMS, available from the American Society of
Agricultural Engineers, 2950 Niles Road, St.
Joseph, MI 49085.
9. NFPA No. 30, FLAMMABLE AND COMBUSTIBLE
LIQUIDS CODE, available same as Item 1.
IMPORTANT SAFETY INSTRUCTIONS
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
Only qualified electricians or contractors should
attempt such installations, which must comply
strictly with applicable codes, standards and
regulations.
1.1 UNPACKING/INSPECTION
After unpacking, carefully inspect the contents
for damage.
• This standby generator set has been factory supplied with a weather protective enclosure that is
intended for outdoor installation only.
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 electrical system from the utility distribution system when the generator is operating (NEC 700, 701 and 702). Failure to isolate an
electrical system by such means will result in
damage to the generator and also may result in
injury or death to utility power workers due to
backfeed of electrical energy.
If any loss or damage is noted at time of delivery, have
the person(s) making the delivery note all damage on
the freight bill or affix his or her signature under the
consignor's memo of loss or damage.
If there is loss or damage after delivery, separate the
damaged materials and contact the carrier for claim
procedures.
“Concealed damage” is understood to mean damage
to the contents of a package that is not in evidence at
the time of delivery, but is discovered later.
1.2 PROTECTION SYSTEMS
Unlike an automobile engine, the generator may have
to run for long periods of time with no operator present to monitor engine conditions. For that reason, the
engine is equipped with the following systems that
protect it against potentially damaging conditions:
1. Low Oil Pressure Sensor 3. Overcrank
2. High Temperature Sensor 4. Overspeed
There are LED readouts on the control panel to noti-
fy personnel that one of these faults has occurred.
There is also a “System Set” LED that is described
below.
1.3 SYSTEM SET LED
The “System Set” LED is lit when all of the following
conditions are true:
1. The AUTO/OFF/MANUAL switch is set to the
AUTO position.
2. The utility voltage being supplied to the unit is
being sensed by the Control PCB. If the utility
sense voltage is not connected to the unit or if it
is below 168 volts AC, then the system set light
will flash rapidly. This indicates that if the
AUTO/OFF/MANUAL switch is placed in the Auto
position , the generator will start.
3. The “Not In Auto” dip switch is set to the OFF
position on the control board.
4. No alarms are present, for example, low oil pressure, high temperature, etc.
Section 1 — General Information
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
4 Generac®Power Systems, Inc.
DANGER
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Section 1 — General Information
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
Generac®Power Systems, Inc. 5
1.4 THE GENERATOR
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Figure 1.2 – 12 kW/15 kW, V-twin GT-990/760 Engine
Figure 1.1 – 7 kW, Single Cylinder GH-410 Engine
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6 Generac®Power Systems, Inc.
Section 1 — General Information
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
1.5 SPECIFICATIONS
1.5.1 GENERATOR
Model 04673 Model 04674 Model 04675
Rated Max. Continuous Power Capacity (Watts*) 6,000 NG/7,000 LP 12,000 NG/12,000 LP 13,000 NG/15,000 LP
Rated Voltage 120/240 120/240 120/240
Rated Max. Continuous Load Current (Amps)
120 Volts + 50.0 NG/58.3 LP 100 NG/100.0 LP 108.3 NG/125.0 LP
240 Volts 25.0 NG/29.2 LP 50 NG/50.0 LP 54.2 NG/62.5 LP
Main Line Circuit Breaker 30 Amp 50 Amp 60 Amp/70 Amp
Phase 1 1 1
Number of Rotor Poles 2 2 2
Rated AC Frequency 60 Hz 60 Hz 60 Hz
Power Factor 1 1 1
Recommended Air Filter Generac Part # C8127 Generac Part # C8127 Generac Part # C8127
Battery Requirement Group 26/26R Group 26/26R Group 26/26R
at -17.8° C ( 0° F) 12 Volts and 12 Volts and 12 Volts and
350 Cold-cranking 525 Cold-cranking 525 Cold-cranking
Amperes Minimum Amperes Minimum Amperes Minimum
Weight 375 Pounds 470 Pounds 487 Pounds
Output Sound Level @ 23 ft (7m) at full load 68 db (A) 70.5db (A) 71.5 db (A)
Normal Operating Range -20°F (-28.8°C) to 104°F (40°C)
* Maximum wattage and current are subject to and limited by such factors as fuel Btu content, ambient temperature, altitude, engine power and condition, etc. Maximum power
decreases about 3.5 percent for each 1,000 feet above sea level; and also will decrease about 1 percent for each 6° C (42° F) above 16° C (60° F).
+ Total current in TWO separate curcuits. Current in each curcuit must not exceed the value stated for 240V.
1.5.2 ENGINE
Model 04673 Model 04674 Model 04675
Type of Engine GH-410 GT-990 GT-990
Number of Cylinders 1 2 2
Rated Horsepower 14.5 @ 3,600 rpm 30 @ 3,600 rpm 30 @ 3,600 rpm
Displacement 410cc 992cc 992cc
Cylinder Block Aluminum w/Cast Aluminum w/Cast Aluminum w/Cast
Iron Sleeve Iron Sleeve Iron Sleeve
Valve Arrangement Overhead Valves Overhead Valves Overhead Valves
Ignition System Solid-state w/Magneto Solid-state w/Magneto Solid-state w/Magneto
Recommended Spark Plug RC14YC RC12YC RC12YC
Spark Plug Gap 0.76 mm (0.030 inch) 0.508 mm (0.020 inch) 0.508 mm (0.020 inch)
Compression Ratio 8.6:1 9.5:1 9.5:1
Starter 12 Vdc 12 Vdc 12Vdc
Oil Capacity Including Filter Approx. 1.5 Qts Approx. 1.7 Qts Approx. 1.7 Qts
Recommended Oil Filter Generac Part # 70185 Generac Part # 70185 Generac Part # 70185
Recommended Air Filter Generac Part # 0C8127 Generac Part # 0C8127 Generac Part # 0C8127
Operating RPM 3,600 3,600 3,600
Generac®Power Systems, Inc. 7
1.6 FUEL REQUIREMENTS
AND RECOMMENDATIONS
With LP gas, use only the vapor withdrawal
system. This type of system uses the vapors formed
above the liquid fuel in the storage tank.
The engine has been fitted with a fuel carburetion
system that meets the specifications of the 1997
California Air Resources Board for tamper-proof dual
fuel systems. The unit will run on natural gas or LP
gas, but it has been factory set to run on natural gas.
Should the primary fuel need to be changed to LP
gas, the fuel system needs to be reconfigured. See
Section 1.9 for instructions on reconfiguration of the
fuel system.
Recommended fuels should have a Btu content of at
least 1,000 Btus per cubic foot for natural gas; or at
least 2,520 Btus per cubic foot for LP gas. Ask the
fuel supplier for the Btu content of the fuel.
Required fuel pressure for natural gas is 5 inches to
7 inches water colum (0.18 to 0.25 psi); and for
liquid propane, 11 inches to 14 inches of water
column (0.4 to 0.5 psi).
NOTE:
Any piping used to connect the generator to the
fuel supply should be of adequate size to ensure
the fuel pressure NEVER drops below 4 inches
water colum for natural gas or 10 inches water column for liquid propane for all load ranges.
1.7 FUEL CONSUMPTION
*Natural gas is in cubic feet per hour.
**LP is in gallons per hour/cubic feet per hour.
1.8 RECONFIGURING THE
FUEL SYSTEM
1.8.1 7 KW, 410CC
To reconfigure the fuel system from NG to LP,
follow these steps (Figure 1.3):
NOTE:
The primary regulator for the propane supply is
NOT INCLUDED with the generator. A fuel pressure of 11 to 14 inches of water column (0.4 to 0.5
psi) to the fuel inlet of the generator MUST BE
SUPPLIED.
1. Turn off the main gas supply (if connected).
2. Open the roof and remove the door.
3. Remove the battery (if installed).
4. Disconnect wire #0 and wire #14 from the gas
solenoid on top of the demand regulator.
5. Remove the carburetor fuel hose from the outlet
port of the demand regulator.
6. Remove the demand regulator by removing the
fastener that retains the regulator mounting
bracket.
7. Remove the square headed steel pipe plug from
outlet port #1 and the brass hose barb fitting
from outlet port #2.
8. Refit the brass hose barb fitting to outlet port #1
and the square headed steel pipe plug to outlet
port #2.
9. Reverse procedure steps 1-5 to reinstall demand
regulator.
10. Reverse the procedure to convert back to natural
gas.
Figure 1.3 – Demand Regulator
NOTE:
The natural gas adjustment screw is preset during
installation and should not need any further
adjustment.
1.8.2 12KW AND 15KW, V-TWIN ENGINES
To reconfigure the fuel system from NG to LP,
follow these steps:
NOTE:
The primary regulator for the propane supply is
NOT INCLUDED with the generator. A fuel pressure of 11 to 14 inches of water column (0.4 to 0.5
psi) to the fuel inlet of the generator MUST BE
SUPPLIED.
1. Turn off the gas supply. (if connected)
2. Open the roof and remove the door.
3. Remove the battery. (if installed)
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◆
Section 1 — General Information
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
Model # Nat. Gas (*) LP Vapor (**)
1/2 Load Full Load 1/2 Load Full Load
04673 66 119 0.82/30 1.47/54
04674 152 215 1.53/56 2.08/76
04675 156 220 1.58/58 2.40/88
HOSE & PL
WITCHED SIDE
FUEL H
BRASS HOSE
FITTIN
AD
TMEN
PL
FUEL H
BRASS HOSE
FITTIN
TLE
POR
FUEL JE
NG FUEL SYSTE
LP FUEL SYSTE
4. Remove the engine air in baffle located on the lefthand side of the battery compartment. Two M6
screws are located on top of the baffle and two
M6 screws are located on the inside of the baffle
towards the back.
5. Remove the small hose clamp and hose from the
fuel regulator. It may be necessary to pry the hose
off of the brass fitting using a screwdriver to gently lift up the hose edge.
6. Remove the small brass hose fitting from the regulator casting.
7. Place the small fuel jet, thread side first, into the
threaded hole originally occupied by the brass
hose fitting (Figure 1.4).
Figure 1.4 - Demand Regulator
8. Using a short No. 2 Phillips screw driver, thread
the small fuel jet into the regulator casting. Do
not over tighten.
9. Apply thread sealant to the threads of the hose fitting and replace it into the regulator body.
10. Re-attach the small hose and hose clamp and
tighten as necessary.
11. Replace the engine air in baffle using the four M6
screws.
12. Identify both brass adjustment screws on the regulator.
NOTE:
One adjustment screw can be accessed from the
front of the unit and the second can be accessed
from the back of the unit enclosure by removing
the plastic hole plug. The screw can be turned
with a long flat blade screwdriver.
13. To adjust the system to run on LP fuel, turn
BOTH adjuster screws 1/2 TURN CLOCKWISE.
The system should now be set for maximum
power and best perfomance. DO NOT, UNDER
ANY CIRCUMSTANCES, REMOVE THE SET
PINS FROM THE REGULATOR HOUSING.
THIS WILL VOID THE WARRANTY.
14. It may be necessary to make minor adjustments
to the preset adjustment screw settings to achieve
maximum power, particularly at higher altitudes.
If experiencing problems with the unit producing
maximum power, follow the procedure in Section
2.6 (Adjusting the Fuel Regulator).
1.9 LOCATION
1.9.1 GENERATOR
Install the generator set, in its protective enclosure,
outdoors, where adequate cooling and ventilating air
is always 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 three feet of space on all sides.
• Where strong prevailing winds blow from one
direction, face the generator air inlet openings to
the prevailing winds.
• Install the generator as close as possible to the fuel
supply, to reduce the length of piping.
• Install the generator as close as possible to the
transfer switch. HOWEVER, REMEMBER THAT
LAWS OR CODES MAY REGULATE THE DISTANCE.
1.9.2 TRANSFER SWITCH
1.9.2.1 7 kW, 12 kW and 15 kW Units
Transfer switches for use with these generators are
sold separately and can be purchased from Generac
Authorized Dealers.
• Install the transfer switch on a firm, sturdy sup-
porting structure.
• To prevent switch distortion, level the switch if nec-
essary. This can be done by placing washers
between the switch enclosure and mounting surface.
• Never install the switch where water or any corro-
sive 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 transfer switch with
this generator may void the warranty.
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G
T
T
U
T
G
OSE
S
L
T
OR
OUSING PORT
JUSTER
SC
S
OU
S
Section 1 — General Information
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
8 Generac®Power Systems, Inc.
TLET PORT
FUEL H
BRASS HOSE
FITTIN
IDLE CIRCUI
POR
1/8 NP
BRASS HOSE
FITTIN
AD
REW
REGULAT
H
MAL
FUEL JE
Generac®Power Systems, Inc. 9
1.10 BATTERY INSTALLATION
Fill the battery with the proper electrolyte fluid if necessary and have the battery fully charged before
installing it.
Before installing and connecting the battery, complete
the following steps:
1. Set the generator's AUTO/OFF/MANUAL switch to
OFF.
2. Turn off utility power supply to the transfer
switch.
3. Remove the 5 amp fuse from the generator control panel.
If the AUTO/OFF/MANUAL switch is not set to
its OFF position, the generator can crank and
start as soon as the battery cables are connected. If the utility power supply is not turned off,
sparking can occur at the battery posts and
cause an explosion.
Battery cables were factory connected at the generator (Figure 1.5). Connect cables to battery posts as
follows:
4. Connect the red battery cable (from starter contactor) to the battery post indicated by a positive,
POS or (+).
5. Connect the black battery cable (from frame
ground) to the battery post indicated by a negative, NEG or (—).
6. Replace the 5 amp fuse in the generator control
panel.
NOTE:
Damage will result if battery connections are made
in reverse.
Figure 1.5 – Battery Cable Connections
NOTE:
The generator is equipped with a battery trickle
charger that is active when the unit is set up for
automatic operation. With the battery installed
and utility power source voltage available to the
transfer switch, the battery receives a trickle
charge while the engine is not running, to prevent
self-discharge. The trickle charger is designed to
help extend the life of the battery by maintaining
the battery when the unit is not running. The
trickle charge feature cannot be used to recharge
a discharged battery.
1.11 THE BATTERY
Servicing of the battery is to be performed or supervised by personnel knowledgeable of batteries and
the required precautions. Keep unauthorized personnel away from batteries.
When replacing the battery, use the following type of
battery: Group 26/26R 12-volt battery with a rating of
350 cold-cranking amps minimum for 7 kW; 525
cold-cranking amps minimum for 12 and 15 kW at
-17.8º C (0º F) minimum. When using a maintenancefree battery, it is not necessary to check the specific
gravity or electrolyte level. Have these procedures
performed at the intervals specified in the “Service
Schedule.” A negative ground system is used. Battery
connections are shown on the wiring diagrams. Make
sure the battery is correctly connected and terminals
are tight. Observe battery polarity when connecting
the battery to the generator set.
Do not dispose of the battery in a fire. The
battery is capable of exploding.
A battery presents a risk of electrical shock
and high short circuit current. The following
precautions are to be observed when working
on batteries:
• Remove watches, rings or other metal objects;
• Use tools with insulated handles;
• Wear rubber gloves and boots;
• Do not lay tools or metal parts on top of the
battery; and
• Disconnect charging source prior to connecting or dis-
connecting battery terminals.
Do not open or mutilate the battery. Released
electrolyte has been known to be harmful to
the skin and eyes, and to be toxic.
The electrolyte is a dilute sulfuric acid that is
harmful to the skin and eyes. It is electrically
conductive and corrosive.
!
!
Section 1 — General Information
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
DANGER
10 Generac®Power Systems, Inc.
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, immediately
flush thoroughly 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 1 pound (500 grams) bicarbonate
of soda to 1 gallon (4 liters) or 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 procedures are to be followed:
• DO NOT SMOKE when near the battery;
• DO NOT cause flame or spark in battery area; and
• Discharge static electricity from body before touching the battery by first touching a grounded metal
surface.
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.
2.1 BEFORE INITIAL START-UP
Before starting, complete the following:
1. Set the generator’s main circuit breaker to its
OFF (or open) position.
2. Set the generator's AUTO/OFF/MANUAL switch to
the OFF position.
3. Turn OFF the utility power supply to the transfer
switch using the means provided (such as the
utility main line circuit breaker).
4. Check the engine crankcase oil level and, if nec-
essary, fill to the dipstick FULL mark with the
recommended oil. Do not fill above the FULL
mark.
5. Check the fuel supply. Gaseous fuel lines must
have been properly purged and leak tested in
accordance with applicable fuel-gas codes. All
fuel shutoff valves in the fuel supply lines must be
open.
Never operate the engine with the oil level
below the “Add” mark on the dipstick. Doing
this could damage the engine.
2.2 CHECK TRANSFER SWITCH
OPERATION
Refer to Section 3.5 of the owner’s manual for manual operation procedures.
Do not attempt manual transfer switch operation until all power voltage supplies to the
transfer switch have been positively turned off.
Failure to turn off all power voltage supplies
will result in extremely hazardous and possibly
fatal electrical shock.
2.3 ELECTRICAL CHECKS
Complete electrical checks as follows:
1. Turn on the utility power supply to the transfer
switch using the means provided (such as a utility main line circuit breaker).
The transfer switch is now electrically “hot.”
Contact with “hot” parts will result in extremely hazardous and possibly fatal electrical shock.
Proceed with caution.
2. Use an accurate AC voltmeter to check utility
power source voltage across terminals N1 and
N2. Nominal line-to-line voltage should be 240
volts AC.
3. Check utility power source voltage across termi-
nals N1 and the transfer switch neutral lug; then
across terminal N2 and neutral. Nominal line-toneutral voltage should be 120 volts AC.
4. When certain that utility supply voltage is com-
patible with transfer switch and load circuit ratings, turn OFF the utility power supply to the
transfer switch.
5. Set the generator's main circuit breaker to its
OFF (or open) position. Initial tests will be conducted at no-load condition.
6. On the generator panel, set the AUTO/OFF/MAN-
UAL switch to MANUAL. The engine should crank
and start.
7. Let the engine warm up for about five minutes to
allow internal temperatures to stabilize. Then, set
the generator’s main circuit breaker to its ON (or
closed) position.
Proceed with caution! Generator power voltage
is now supplied to the transfer switch. Contact
with live transfer switch parts will result in
dangerous and possibly fatal electrical shock.
Section 2 — Post Installation Start-up and Adjustments
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
!
!
DANGER
DANGER
DANGER
Generac®Power Systems, Inc. 11
8. Connect an accurate AC voltmeter and a frequency meter across transfer switch terminal lugs E1
and E2. Voltage should be 242-252 volts; frequency should read about 61-63 Hertz.
9. Connect the AC voltmeter test leads across terminal lug E1 and neutral; then across E2 and neutral. In both cases, voltage reading should be 121126 volts AC.
10. Set the generator’s main circuit breaker to its
OFF (or open) position. Let the engine run at noload for a few minutes to stabilize internal engine
generator temperatures.
11. Set the generator's AUTO/OFF/MANUAL switch to
OFF. The engine should shut down.
NOTE:
It is important not to proceed until certain that
generator AC voltage and frequency are correct
and within the stated limits. Generally, if both AC
frequency and voltage are high or low, the engine
governor requires adjustment. If frequency is correct, but voltage is high or low, the generator’s
voltage regulator requires adjustment.
2.4 GENERATOR TESTS UNDER LOAD
To test the generator set with electrical loads applied,
proceed as follows:
1. Set generator’s main circuit breaker to its OFF
(or open) position.
2. Set the generator's AUTO/OFF/MANUAL
switch to OFF.
3. Turn OFF the utility power supply to the transfer
switch, using the means provided (such as a utility main line circuit breaker).
Do not attempt manual transfer switch operation until all power voltage supplies to the
transfer switch have been positively turned off.
Failure to turn off all power voltage supplies
will result in extremely hazardous and possibly
fatal electrical shock.
4. Manually set the transfer switch to the STANDBY
position, i.e., load terminals connected to the
generator's E1/E2 terminals. The transfer switch
operating lever should be down.
5. Set the generator's AUTO/OFF/MANUAL switch to
MANUAL. The engine should crank and start
immediately.
6. Let the engine stabilize and warm up for a few
minutes.
7. Set the generator’s main circuit breaker to its ON
(or closed) position. Loads are now powered by
the standby generator.
8. Turn ON electrical loads. Apply an electrical load
equal to the full rated wattage/amperage capacity
of the installed generator.
9. Connect an accurate AC voltmeter and a frequency meter across terminal lugs E1 and E2. Voltage
should be greater than 230 volts; frequency
should be greater than 58 Hertz.
10. Let the generator run at full rated load for 20-30
minutes. Listen for unusual noises, vibration or
other indications of abnormal operation. Check
for oil leaks, evidence of overheating, etc.
11. When testing under load is complete, turn OFF
electrical loads.
12. Set the generator's main circuit breakers to their
OFF (or open) positions.
13. Let the engine run at no-load for a few minutes.
14. Set the AUTO/OFF/MANUAL switch to OFF. The
engine should shut down.
2.5 CHECKING AUTOMATIC
OPERATION
To check the system for proper automatic operation,
proceed as follows:
1. Set the generator’s main circuit breaker to it’s
OFF (or open) position.
2. Check that the AUTO/OFF/MANUAL switch is set
to OFF.
3. Manually set the transfer switch to the UTILITY
position, i.e., load terminals connected to the utility power source side.
4. Turn ON the utility power supply to the transfer
switch, using the means provided (such as a utility main line circuit breaker).
5. Set the AUTO/OFF/MANUAL switch to AUTO.
Then set the generator’s main circuit breaker to
its ON (or closed) position. The system is now
ready for automatic operation.
6. Turn OFF the utility power supply to the transfer
switch.
With the AUTO/OFF/MANUAL switch at AUTO, the
engine should crank and start when the utility source
power is turned OFF. After starting, the transfer
switch should connect load circuits to the standby
side. Let the system go through its entire automatic
sequence of operation.
With the generator running and loads powered by
generator AC output, turn ON the utility power supply to the transfer switch. The following should
occur:
• After about 15 seconds, the switch should transfer
loads back to the utility power source.
• About one minute after retransfer, the engine
should shut down.
Section 2 — Post Installation Start-up and Adjustments
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
12 Generac®Power Systems, Inc.
2.6 ADJUSTING THE REGULATOR
(NATURAL GAS ONLY)
Although the generator has been factory set to provide maximum power, it may be necessary in some
areas to adjust this setting. Because natural gas has
different BTU or power content across the country
the engine may not perform as designed.
If experiencing engine problems at high or full load
conditions follow these steps. It will require a frequency meter to perform this procedure.
1. Turn off utility power to the main distribution
panel in the house. This can be done by switching
the service main breaker to the off or open position.
2. Allow the generator to start before loading the
generator. Confirm the no-load frequency with
the roof open and door off is set at 63-63.5 Hz.
Transfer load to emergency circuits.
3. Turn on appliances, lights, pumps, etc., that are
on the emergency circuits in an attempt to fully
load the generator. Be cautious not to overload
the generator. Use the following chart as a guide:
4. When full load has been achieved. Connect a fre-
quency meter to the output lugs of the generator’s
main line circuit breaker.
5. The fuel regulator is fitted with one (7 kW), or two
(12 & 15 kW) adjustment screws. While watching
the frequency meter, slowly turn the adjustment
screw clockwise or counterclockwise one at a
time until highest frequency is read on the meter.
Only limited adjustment is available between the
set pins. Under no circumstances should any of
the pins be removed (Figures 2.1 and 2.2).
Figure 2.1 — Dual Fuel Regulators
6. When the highest frequency is reached maximum
power has been set. Then turn both adjustment
screws 1/4 turn counterclockwise. Regulator is
now set.
Figure 2.2 — Placement of Regulator
7. Turn utility power to the main distribution panel
back on. This can be done by switching the service main breaker to the on or closed position.
Allow the generator to shut down.
Do not make any unnecessary adjustments.
Factory settings are correct for most applications. However, when making adjustments, be
careful to avoid overspeeding the engine.
If this procedure or equipment are not available,
locate the nearest Generac Guardian Dealer and they
can perform the adjustments.
NOTE:
A service fee may be charged for this adjustment.
2.7 ENGINE GOVERNOR ADJUSTMENT
If both AC frequency and voltage are correspondingly
high or low, adjust the engine governor as follows:
2.7.1 7 KW UNITS
1. Loosen the governor clamp bolt (Figure 2.3).
2. Hold the governor lever at its wide open throttle
position, and rotate the governor shaft clockwise
as far as it will go. Then, tighten the governor
lever clamp bolt to 70 inch-pounds (8 N-m).
3. Start the generator; let it stabilize and warm up
at no-load.
4. Connect an AC frequency meter across the generators AC output leads.
5. Turn the speed adjust nut to obtain a frequency
reading of 63 Hz.
◆
!
Section 2 — Post Installation Start-up and Adjustments
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
Unit 120 Volts 240 Volts
7 kW 50.0 amps 25.0 amps
12 kW 83.3 amps 41.6 amps
15 kW 108.3 amps 54.1 amps
Adjustment Screw
V-twin
Adjustment
Screw
(Both Sides)
Set Pin
(Both Sides)
Adjustment
Screw
(One Side
Only)
410
Set
Pin
Generac®Power Systems, Inc. 13
Section 2 — Post Installation Start-up and Adjustments
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
6. When frequency is correct at no load, check the
AC voltage reading. If voltage is incorrect, the voltage regulator may require adjustment.
Figure 2.3 — Single Cylinder Engine Governor
Adjustment
2.7.2 12 KW AND 15 KW UNITS
1. Loosen governor clamp bolt (See Figure 2.4).
Figure 2.4 — V-twin Engine Governor
Adjustment
2. Completely remove the idle spring.
3. With governor arm at wide open throttle position,
rotate governor shaft fully clockwise. Tighten
clamp bolt to 84 inch-pounds.
4. Start unit and apply full load. Use full load speed
adjust screw (Figure 2.5) to adjust frequency to
58 Hz.
5. Remove load, stop engine, loosen the idle adjust
screw and reconnect the idle spring.
6. Using a hand, push the governor arm to the
closed throttle position. Make sure the idle spring
does not stretch at all.
7. Restart the unit.
8. Slowly turn the idle adjust screw to adjust the noload idle frequency to 63-63.5 Hz.
9. The governor is now set.
Figure 2.5 — V-twin Full Load Speed Adjust
Screw
2.7.3 ADDITIONAL CORROSION
PROTECTION
Periodically spray all engine linkage parts and brackets with corrosion inhibiting spray such as WD-40 or
a comparable product.
2.8 VOLTAGE REGULATOR
ADJUSTMENT
With the frequency between 62-63.5 Hertz, slowly
turn the slotted potentiometer (Figure 2.6) until line
voltage reads 244-252 volts.
NOTE:
Remove the access panel on top of the control
panel to adjust the voltage regulator.
Figure 2.6 – Voltage Adjustment Potentiometer
◆
◆
GOVERNOR
SHAFT
GOVERNOR
CLAMP
BOLT
ADJUST
SCREW
Full Load Speed Adjust Screw
Idle Spring
Governor
Shaft
(Rotate
Clockwise)
Governor Clamp Bolt
No Load Idle
Adjustment Screw
14 Generac®Power Systems, Inc.
Section 3 — Operation
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
NOTE:
The voltage regulator is housed above the generator's control panel. The regulator maintains a voltage in direct proportion to frequency. For example,
at 62 Hertz, line-to-neutral voltage will be 124 volts.
3.1 BREAK-IN PROCEDURE
Once the unit has been installed, with utility power
connected to the transfer switch, and all electrical
checks have been made, it is strongly recommended
that the following “Break-in Procedure” be completed
to ensure correct generator operation in the future.
1. Set the generator’s AUTO/OFF/MANUAL switch to
AUTO.
2. Turn OFF the utility power supply to the transfer
switch using the means provided (such as a utility main line circuit breaker).
3. The unit will start, and the transfer switch will
transfer to standby.
4. Run the unit for one hour at 25 percent load.
5. Run the unit for one hour at 50 percent load.
6. Run the unit for one hour at 75 percent load.
7. Run the unit for one hour at 100 percent load.
8. Turn ON the utility power supply to the transfer
switch, which will allow the transfer switch to
transfer back to utility power. The unit will continue to run for one minute and then shut down.
9. Allow the unit to cool.
10. Drain the oil and remove the oil filter. Replace the
oil filter according to Section 4.4, “Changing the
Oil Filter”. Replace the oil with synthetic oil as
recommended in Section 4.3, “Changing the
Engine Oil”.
11. The generator is now ready for service.
3.2 USING THE AUTO/OFF/MANUAL
SWITCH (FIGURE 3.1)
3.2.1 “AUTO” POSITION
Selecting this switch position activates fully automatic
system operation. It also permits starting and exercising
of the engine every seven days with the exercise timer (see
Section 3.6). This position also is used for remote starting, when it is set up.
3.2.2 “OFF” POSITION
This switch position shuts down the engine. This
position also prevents automatic operation.
3.2.3 “MANUAL” POSITION
Set the switch to MANUAL to crank and start the
engine. Transfer to standby power will not occur
unless there is a utility failure.
Figure 3.1 – Generator Control Panel
With the switch set to AUTO, the engine may
crank and start at any time without warning.
Such automatic starting normally occurs when
utility power source voltage drops below a preset level or during the normal exercise cycle. To
prevent possible injury that might be caused by
such sudden starts, always set the switch to
OFF and remove both fuses before working on
or around the generator or transfer switch.
Then, place a “Do Not Operate” tag on the generator panel and on the transfer switch.
3.3 AUTOMATIC TRANSFER
OPERATION
To select automatic operation, do the following:
1. Make sure the transfer switch main contacts are
set to their “Utility” position, i.e., loads connected
to the utility power source (Figure 3.2).
2. Be sure that normal utility power source voltage
is available to transfer switch terminal lugs N1
and N2.
3. Set the generator’s AUTO/OFF/MANUAL switch to
AUTO.
4. Set the generator’s main circuit breaker to its ON
(or closed) position.
With the preceding steps complete, the generator will
start automatically when utility source voltage drops
below a preset level. After the unit starts, loads are
transferred to the standby power source. Refer to
Section 3.4, “Sequence of Automatic Operation.”
3.4 SEQUENCE OF AUTOMATIC
OPERATION
The generator’s control panel houses a control logic
circuit board. This board constantly monitors utility
power source voltage. Should that voltage drop below
a preset level, circuit board action will signal the
engine to crank and start. After the engine starts, the
circuit board signals the transfer switch to activate
and connect load circuits to the standby power supply (load terminal lugs T1/T2 connect to terminal
lugs E1/E2).
!
FUSE
5A
FUSE
15A
OFFAUTO
SET
EXERCISE
TIME
MAN.
Locat e your nearest dealer at :
R
POWER SYSTEMS, INC.
FLA SHING GR EEN L ED=
4FLASHINGREDLEDS=
R
SYSTEM SET
LOW OIL
HIGH TEMP.
OVER SPEED
OVER CRANK
N O U T IL IT Y S E N S E
EX ERCISER N OT S ET
Generac®Power Systems, Inc. 15
Upon restoration of utility source voltage above a preset level, generator circuit board action signals the
transfer switch to transfer loads back to that power
supply. After retransfer, the engine is signalled to shut
down.
The actual sequence of operation is controlled by
sensors and timers on a control logic circuit board,
as follows:
A. Utility Voltage Dropout Sensor
• This sensor monitors utility source voltage.
• If utility source voltage drops below about 70 percent of the nominal supply voltage, the sensor
energizes a 15-second timer.
• Once the timer has expired, the engine will crank
and start.
B.Engine Warm-up Time Delay
• This mechanism lets the engine warm up for
about 10 seconds before the load is transferred
to a standby source.
C.Standby Voltage Sensor
• This sensor monitors generator AC output voltage. When the voltage has reached 50 percent of
the nominal rated voltage, transfer to standby
can occur.
D.Utility Voltage Pickup Sensor
• This sensor monitors utility power supply voltage. When that voltage is restored to above 70
percent of the nominal source voltage, a retransfer time delay starts timing.
E.Retransfer Time Delay
• This timer runs for about 15 seconds.
• At end of a 15-second delay, circuit board action
de-energizes the transfer relay in the transfer
switch.
• Retransfer to utility power source then occurs.
F. Engine Cool-down Timer
• When the load is transferred back to utility power
source, the engine cool-down timer starts timing.
• The timer will run for about one minute, and the
generator will then shut down.
3.5 MANUAL TRANSFER OPERATION
3.5.1 TRANSFER TO GENERATOR
POWER SOURCE
To start the generator and activate the transfer switch
manually, proceed as follows:
1. Set the generator’s main circuit breaker to its
OFF (or open) position.
2. Set the generator’s AUTO/OFF/MANUAL switch
to OFF.
3. Turn OFF the utility power supply to the transfer
switch using the means provided (such as a
utility main line circuit breaker).
Do not attempt to activate the transfer switch
manually until all power voltage supplies to
the switch have been positively turned off.
Failure to turn off all power voltage supplies
may result in extremely hazardous and possibly
fatal electrical shock.
4. Use the manual transfer handle inside the transfer switch to move the main contacts to their
“Standby” position, i.e., loads connected to the
standby power source (Figure 3.2).
5. To crank and start the engine, set the
AUTO/OFF/MANUAL switch to MANUAL.
6. Let the engine stabilize and warm up for a few
minutes.
7. Set the generator’s main circuit breaker to its ON
(or closed) position. The standby power source
now powers the loads.
Figure 3.2 – Manual Transfer Switch Operation
3.5.2 TRANSFER BACK TO UTILITY POWER
SOURCE
When utility power has been restored, transfer back
to that source and shut down the generator. This can
be accomplished as follows:
1. Set the generator’s main circuit breaker to its
OFF (or open) position.
2. Let the engine run for a minute or two at no-load
to stabilize the internal temperatures.
3. Set the generator’s AUTO/OFF/MANUAL switch to
its OFF (or open) position. The engine should
shut down.
4. Check that utility power supply to the transfer
switch is turned OFF.
Section 3 — Operation
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
DANGER
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