Generac Power Systems Portable Generator 43733 User Manual

Owner’s Manual  
Liquid-cooled, Prepackaged  
Standby Generators  
Models: 0043733, 0043734  
& 0043735  
(40 kW/Single-phase w/  
200 Amp Transfer  
Switch)  
0046262, 0046263  
& 0046264  
(40 kW/Single-phase w/  
200 Amp Transfer  
Switch California  
Emissions)  
Not intended for use in critical life support applications.  
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!
ONLY QUALIFIED ELECTRICIANS OR CONTRACTORS SHOULD ATTEMPT  
INSTALLATION!!  
DEADLY EXHAUST FUMES. OUTDOOR INSTALLATION ONLY!  
This manual should remain with the unit.  
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Table of Contents  
Guardian Liquid-cooled 40 kW Generator  
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  
Section 3 – Operation ..................................12  
3.1 Control Console Components ......................12  
3.1.1 AC Voltmeter ..................................12  
3.1.2 AC Ammeter ..................................12  
3.1.3 AC Frequency Meter ......................12  
3.1.4 DC Voltmeter..................................12  
3.1.5 Hourmeter......................................12  
3.1.6 Auto/Off/Manual Switch..................12  
3.1.7 Fault Indicator Lamp......................12  
3.1.8 15-amp Fuse ..................................12  
3.1.9 7.5 Amp Inline Fuse ......................12  
3.1.10 Voltage-phase Selector Switch ........12  
3.1.11 Set Exercise Time Switch ..............12  
Safety Rules ......................................................2  
Section 1 – General Information..................4  
1.1 Unpacking/Inspection ..................................4  
1.1.1 Lifting the Generator........................4  
1.2 The Generator..............................................4  
1.3 Generator AC Connection Systems ..............4  
1.4 Prepackaged Transfer Switch ......................4  
1.5 Automatic System Operation........................4  
1.6 Main Circuit Breaker ..................................5  
1.7 Engine Protective Devices ............................5  
1.7.1 Low Oil Pressure Switch ..................5  
1.7.2 High Coolant  
3.2 Using the Auto/Off/Manual Switch..............12  
3.2.1 Auto” Position................................12  
3.2.2 “Off Position..................................13  
3.2.3 “Manual” Position ..........................13  
3.3 Automatic Transfer Operation....................13  
3.4 Sequence of Automatic Operation ..............13  
3.5 Engine Heater ..............................................13  
3.6 Weekly Exercise Cycle ................................14  
Temperature Switch ........................5  
1.7.3 Low Coolant Level Switch ................5  
1.7.4 Overspeed Shutdown ......................5  
1.7.5 Overcrank Shutdown ......................5  
1.7.6 DC Fuse............................................5  
1.8 Specifications ..............................................5  
1.8.1 Generator ........................................5  
1.8.2 Engine..............................................6  
1.9 Fuel Requirements  
and Recommendations ............................6  
1.9.1 Conversion to LP Gas Vapor ............6  
1.10 Engine Oil Recommendations ......................7  
1.11 Coolant ........................................................7  
1.12 Emission Control System ............................7  
Section 4 – Maintenance ............................14  
4.1 Checking the Engine Oil Level....................14  
4.2 Changing the Engine Oil and Filter ............15  
4.2.1 Engine Oil Recommendations ........15  
4.2.2 Oil and Filter Change Procedure......15  
4.3 Changing the Engine Air Cleaner................15  
4.4 Spark Plugs................................................16  
4.5 Battery Maintenance ..................................16  
4.5.1 Battery Replacement ......................16  
4.6 Cooling System ..........................................17  
4.7 Overload Protection for  
Engine DC Electrical System......................17  
4.8 DC Fuse ....................................................17  
4.9 Engine Coolant ..........................................17  
4.10 Miscellaneous Maintenance........................17  
4.10.1 Cleaning the Generator ..................17  
4.10.2 Rodent Protection ..........................17  
4.11 Out of Service Procedure ..........................18  
4.11.1 Removal From Service....................18  
4.11.2 Return to Service............................18  
4.12 Service Schedule........................................19  
Section 2 – Installation ..................................8  
2.1 Basic Standby Electric System ....................8  
2.2 Emergency Circuit Isolation Method ............9  
2.3 Total Circuit Isolation Method......................9  
2.4 Grounding the Generator ............................9  
2.5 Generator AC Neutral Connections ..............9  
2.6 Transfer Switch Start Signal Connections....9  
2.6.1 Pre-Packaged Type Switch................9  
2.6.2 “GTS” Type Switch ..........................9  
2.7 Battery Installation ....................................10  
2.7.1 Vented Batteries ............................10  
2.8 Preparation Before Start-up ......................10  
2.8.1 Prior to Initial Start-up ..................11  
2.8.2 Transfer Switch..............................11  
2.8.3 Fuel System....................................11  
2.8.4 Generator Set Lubrication..............11  
2.8.5 Engine Coolant ..............................11  
2.8.6 Belt Tension ..................................11  
2.8.7 Electrical System............................11  
2.8.8 Rodent Protection ..........................11  
Section 5 – Troubleshooting ......................20  
Section 6 – Electrical Data ..........................21  
Section 7 – Exploded Views and  
Parts Lists ..................................30  
Section 8 – Notes ..........................................58  
Section 9 – Warranty ....................................60  
®
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Important Safety Instructions  
Guardian Liquid-cooled 40 kW Generator  
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 and potential operators of this equipment.  
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SAVE THESE INSTRUCTIONS – This manual contains important instructions that should be  
followed during installation and maintenance of the generator and batteries.  
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GENERAL HAZARDS  
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WARNING:  
The engine exhaust from this product  
contains chemicals known to the state  
of California to cause cancer, birth  
defects or other reproductive harm.  
For safety reasons, Generac recommends that the  
installation, initial start-up and maintenance of this  
equipment is carried out by a Generac/Guardian  
Authorized Dealer.  
• 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 gener-  
ator is installed, operated and serviced in accordance  
with the manufacturer’s instructions and recommen-  
dations. Following installation, do not do anything  
that might render the unit unsafe or in noncompli-  
ance with the aforementioned codes, standards, laws  
and regulations.  
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!
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 gen-  
erator 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 fun-  
damental rules or precautions.  
• The engine exhaust fumes contain carbon monoxide,  
which can be DEADLY. This dangerous gas, if  
breathed in sufficient concentrations, can cause  
unconsciousness or even death. For that reason, ade-  
quate 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 in any room or building housing the gen-  
erator to prevent buildup of explosive gases and to  
ensure correct generator operation. Do not alter the  
installation or permit even partial blockage of ventila-  
tion provisions, as this can seriously affect safe oper-  
ation of the generator.  
Generac cannot possibly anticipate every possible  
circumstance that might involve a hazard. The warn-  
ings 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, satisfy your-  
self that it is safe for others. Also make sure the proce-  
dure, 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 possi-  
ble 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.  
• Keep the area around the generator clean and unclut-  
tered. Remove any materials that could become haz-  
ardous.  
• When working on this equipment, remain alert at all  
times. Never work on the equipment when physically  
or mentally fatigued.  
Parts of the generator are rotating and/or hot  
during operation. Exercise care near running gen-  
!
erators.  
®
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Important Safety Instructions  
Guardian Liquid-cooled 40 kW Generator  
• Inspect the generator regularly, and promptly repair • Generators installed with an automatically transfer  
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.  
switch will crank and start automatically when nor-  
mal (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, immedi-  
ately 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.  
ELECTRICAL HAZARDS  
• All generators covered by this manual produce dan-  
gerous electrical voltages and can cause fatal electri-  
cal shock. Utility power delivers extremely high and  
dangerous voltages to the transfer switch as does the  
standby generator when it is in operation. Avoid con-  
tact with bare wires, terminals, connections, etc.,  
while the unit is running. Ensure all appropriate cov-  
ers, guards and barriers are in place before operating  
the generator. If work must be done around an oper-  
ating 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.  
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. If there  
are any questions pertaining to fire extinguishers,  
consult the local fire department.  
EXPLOSION HAZARDS  
• The National Electrical Code (NEC) 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.  
• 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.  
• Wire gauge sizes of electrical wiring, cables and cord  
sets must be adequate to handle the maximum elec- • Generac generator sets may operate using one of sev-  
trical current (ampacity) to which they will be sub-  
eral types of fuels. All fuel types are potentially FLAM-  
MABLE and/orEXPLOSIVE 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. uel  
supply lines must be properly installed, purged and  
leak tested according to applicable fuel-gas codes  
before placing this equipment into service.  
jected to.  
• Before installing or servicing this (and related) equip-  
ment, 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 genrator electric  
system from the utility electric system while in oper-  
ation. 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.  
• 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.  
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Section 1 — General Information  
Guardian Liquid-cooled 40 kW Generator  
When the two windings are connected in series, a 240-  
volt, 60-Hertz AC output results. Typically, the two “hot”  
leads in the circuit are Wires 11 and 44. The neutral  
leads are the junction of Wires 22 and 33.  
1.1 UNPACKING/INSPECTION  
After unpacking, carefully inspect the contents for dam-  
age.  
• This standby generator set has been factory installed  
in an all-weather, metal enclosure that is intended  
exclusively for outdoor installation.  
Figure 1.1 – Single-phase  
Generator AC Connection System  
If this generator is used to power electrical load  
circuits normally powered by a utility power  
source, code requires to install a transfer switch.  
The transfer switch must effectively isolate the  
electrical system from the utility distribution sys-  
tem when the generator is operating (NEC 701).  
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.  
Neutral Block  
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.  
1.4 PREPACKAGED TRANSFER SWITCH  
The transfer switch shipped with this generator is rated  
200 amps maximum at 120/240 volts AC single-phase.  
The enclosure of the transfer switch is NEMA 3R. This  
type of enclosure is intended for indoor or outdoor use.  
If there is loss or damage after delivery, separate the  
damaged materials and contact the carrier for claim  
procedures.  
Follow these rules:  
• Install the transfer switch on a firm, sturdy support-  
ing 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 any corrosive sub-  
stance might drop onto the enclosure.  
“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.  
1.1.1 LIFTING THE GENERATOR  
• Where practical, protect the switch against excessive  
moisture, dust, dirt, lint, and construction grit.  
Always prevent corrosive vapors from coming in con-  
tact with enclosure.  
When lifting or hoisting equipment is used, be  
careful not to touch overhead power lines.  
The generator’s weight of more than 2,000  
pounds requires proper tools and equipment, and  
qualified personnel to be used in all phases of  
handling and unpacking.  
!
1.5 AUTOMATIC SYSTEM OPERATION  
When this generator, along with its transfer switch, has  
been installed and interconnected, a circuit board in the  
generator panel continuously 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 gener-  
ator starts, the transfer switch transfers load circuits so  
the generator can power them.  
1.2 THE GENERATOR  
This liquid-cooled, Guardian generator set is designed  
to supply electrical power to operate critical electrical  
loads during utility power failure. Use this generator as  
a source of electrical power for the operation of 120  
and/or 240-volt, single-phase loads.  
When utility source voltage has been restored, the  
switch transfers back to the utility source voltage, and  
the generator then shuts down after a brief cool-down  
time.  
1.3 GENERATOR AC  
CONNECTION SYSTEMS  
Figure 1.1 represents a single-phase, four-wire genera-  
tor AC connection system. 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 a 120-volt, 60-Hertz AC output.  
®
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Section 1 — General Information  
Guardian Liquid-cooled 40 kW Generator  
1.7.3 LOW COOLANT LEVEL SWITCH  
1.6 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 as follows:  
Should the engine coolant level drop below the level of the  
high coolant temperature switch, it is possible for the  
engine to overheat without automatic shut down. To pre-  
vent 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 1.2).  
Model Number  
0043733, 0043734, 0043735  
Circuit Breaker Rating  
200-amp breaker  
0046262, 0046263, 0046264  
200-amp breaker  
1.7 ENGINE PROTECTIVE DEVICES  
1.7.4 OVERSPEED SHUTDOWN  
The engine has several safety switches that cause  
it to automatically shut down under the following condi-  
tions: low oil pressure, high coolant temperature, low  
coolant level, engine overspeed and overcrank.  
The control module assembly (CMA) circuit board on  
liquid-cooled units receives AC frequency (rpm) signals  
directly from the stator AC power windings. Should AC  
frequency exceed approximately 72 Hertz, circuit board  
action will automatically shut down the engine.  
1.7.1 LOW OIL PRESSURE SWITCH  
This switch is normally closed (N.C.) but is held open by  
engine oil pressure during engine running. Should oper-  
ating oil pressure drop below approximately 10 psi (68  
kPa), the switch contacts close, and the engine shuts down  
automatically (Figure 1.2).  
1.7.5 OVERCRANK SHUTDOWN  
After 90 seconds of crank-rest cycles (about seven sec-  
onds cranking/seven seconds at rest), this function ends  
cranking if the engine fails to start in that 90-second  
span.  
Figure 1.2 – Engine Protective Devices  
1.7.6 DC FUSE  
This fuse is located on the front panel of the control sys-  
tem. 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 uses an  
AGC fuse rated at 15 amps.  
1.8 SPECIFICATIONS  
1.8.1 GENERATOR  
Models..............................0043733, 0043734,, 0043735  
0046262, 0046263, 0046264  
Rated Maximum Continuous  
AC Power Output (kW)*..................................................40  
Rated Voltage (volts) ................................................120/240  
Rated Maximum Continuous  
Current at 240 Volts, Single-phase (amps)................................167  
Number of Rotor Poles ........................................................4  
Driven Speed of Rotor (rpm) ........................................1,800  
Type of Stator ........................................................Four-wire  
1.7.2 HIGH COOLANT TEMPERATURE SWITCH  
Rotor Excitation System..................................Direct Excited  
Brush-type System  
Stator Insulation ....................................................Class “H”  
Rotor Insulation ......................................................Class “F”  
*Rated power of generator is subject to and limited by such factors as ambient tempera-  
ture, altitude, engine condition and other factors. Engine power will decrease about 3.5  
percent for each 1,000 feet above sea level; and also will decrease an additional 1 percent  
for each 6° C (10° F) above 15.5° C (60° F) ambient. Maximum output power of the gener-  
ator is limited by maximum engine power.  
This normally open (N.O.) thermostatic switch has a  
sensing tip that is immersed in captive coolant. Should  
the coolant temperature exceed approximately 121° C  
(250° F), the switch contacts close, which causes the  
engine to shut down automatically (Figure 1.2).  
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Section 1 — General Information  
Guardian Liquid-cooled 40 kW Generator  
1.8.2 GENERATOR AND LOAD COMPATIBILITY  
The generator must be fully compatible with the rated  
voltage, number of phases and frequency of the con-  
nected electrical loads. The generator, connected elec- type of system uses the vapors formed above the liquid  
trical devices, or both, can be damaged if voltage, num-  
ber of phases and frequency are not compatible.  
1.9 FUEL REQUIREMENTS  
AND RECOMMENDATIONS  
With LP gas, use only the vapor withdrawal system. This  
fuel in the storage tank.  
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 your fuel  
supplier for the Btu content of your fuel.  
NOTE:  
This manual assumes that the standby generator has  
been properly selected, installed and interconnected  
by a competent, qualified electrician or installation  
contractor. Once the installation is complete, do  
nothing that may result in noncompatibility between  
the generator and connected electrical loads.  
Fuel pressure for both natural gas and liquid propane  
setups should be 11 inches to 14 inches of water column  
(0.6 psi) at all load ranges.  
Gaseous fuels such as natural gas and liquid  
propane (LP) 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 – install leak detectors accord-  
ingly.  
1.8.3 ENGINE  
Make ............................................................General Motors  
Displacement ......................................4.3 liters (262 cu. in.)  
Cylinder Arrangement ......................................................V-6  
Valve Arrangement ......................................Overhead Valves  
Firing Order ........................................................1-6-5-4-3-2  
Number of Main Bearings....................................................4  
Compression Ratio....................................................9.4-to-1  
No. of Teeth on Flywheel..................................................168  
Ignition System......................................................Electronic  
Ignition Timing at 1,800 rpm ....................40 degrees BTDC  
Rated Horsepower at 1,800 rpm ......................................67  
Spark Plug Gap ....................................0.045 inch (1.1 mm)  
Recommended Spark Plugs ............AC 41-932 or equivalent  
Oil Pressure............................................................30-50 psi  
Crankcase Oil Capacity ....................4.5 U.S. quarts (4.25 L)  
Recommended Engine Oil..................................SAE 15W-40  
Type of Cooling System ............Pressurized, closed recovery  
Cooling Fan ........................................................Pusher Type  
Cooling System Capacity ....................4.5 U.S. gallons (17 L)  
Recommended Coolant........................Use a 50-50 mixture of  
ethylene glycol and soft water.  
1.9.1 CONVERSION TO LP GAS VAPOR  
The generator is shipped from the factory configured for  
using natural gas as fuel. To convert the fuel system to LP  
gas, proceed as follows (Figure 1.3).  
1. Remove end cap from the pressure reducer valve.  
2. Turn the tension screw counterclockwise until all ten-  
sion is removed from the inner spring.  
3. Install and tighten the end cap.  
4. Invert the pressure reducer valve. In other words, turn  
it upside down (end cap facing downward).  
5. Purge and leak test the entire fuel system according to  
gaseous fuel codes. NO LEAKS can appear at any point  
in the system.  
Fuel Consumption  
Figure 1.3 – Conversion to LP Gas Vapor  
Natural Gas ..............................................................720 cfh  
LP Gas ..........................................................288 cfh/7.9gph  
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Section 1 — General Information  
Guardian Liquid-cooled 40 kW Generator  
1.10 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 or SF.” Detergent oils keep the  
engine cleaner and reduce carbon deposits. Use oil hav-  
ing the following SAE viscosity rating, based on the  
ambient temperature range anticipated before the next  
oil change:  
1.12 EMISSIONS CONTROL SYSTEM  
(MODELS 0046262, 0046263 & 0046264)  
This model is equipped with an active exhaust emis-  
sions control system to comply with certain California  
air district regulations for natural gas emergency gener-  
ating sets, including the South Coast Air Quality  
Management District. Do not tamper with or disable  
any part of this system, including the exhaust catalyst,  
carburetor, oxygen sensor, air-fuel ratio controller, sole-  
noid valve and gas regulator. These items are not sub-  
ject to periodic maintenance or adjustment.  
Temperature  
Above 80º F (27º C)  
Oil Grade(Recommended)  
SAE 30W or 15W-40  
SAE 20W-20 or 15W-40  
SAE 10W or 15W-40  
32º to 80º F (-1º C to 27º C)  
Below 32º F (0º C)  
This model is of a size (greater than 50 brakehorse-  
power) that may require a review by air permitting  
authorities prior to installation and operation. Consult  
the local air management district for details and spe-  
cific requirements.  
Any attempt to crank or start the engine before it  
has been properly serviced with the recommended  
oil may result in an engine failure.  
!
Figure 1.4 - Emissions Control System  
1.11 COOLANT  
Use a mixture of half low silicate, ethylene glycol base  
antifreeze and half soft water. Use only soft water and  
only low silicate antifreeze. If desired, add a high quali-  
ty rust inhibitor to the recommended coolant mixture.  
When adding coolant, always add the recommended 50-  
50 mixture.  
DANGER  
Do not remove the radiator pressure cap while  
the engine is hot or serious burns from boiling  
liquid or steam could result.  
!
1.12.1 AIR FUEL RATIO CONTROLLER  
Ethylene glycol base antifreeze is poisonous. Do  
not use mouth to siphon coolant from the radia-  
tor, recovery bottle or any container. Wash  
hands thoroughly after handling. Never store  
used antifreeze in an open container because  
animals are atracted to the smell and taste of  
antifreeze even though it is poisonous to them.  
The air fuel ratio controller is an advanced micro-  
processor designed to work with a three-way catalyst  
and a feedback (rich bias) carburetor to provide close-  
loop fuel management. Its digital adaptive control is  
able to compensate for variations in fuel mixtures and  
engine tunes. It is time based activated. (For example, it  
will activate after 45 seconds from receiving the power  
signal.) The part number for the air fuel ratio controller  
is 0D4221.  
!
Do not use any chromate base rust inhibitor  
with ethylene glycol base antifreeze, or chromi-  
um hydroxide (“green slime”) will form and  
!
cause overheating. Engines that have been oper-  
ated with a chromate base rust inhibitor must  
be chemically cleaned before adding ethylene  
glycol base antifreeze. Using any high silicate  
antifreeze boosters or additives also will cause  
overheating. Generac also recommends that any  
soluble oil inhibitor NOT be used for this equip-  
ment.  
Principle of Operation: The oxygen sensor, installed  
on the exhaust pipe, between the engine and the cat-  
alytic muffler (closer to the engine), continuously moni-  
tors the exhaust gas composition. A feedback signal is  
sent from the oxygen sensor to the air fuel ratio con-  
troller, which controls the fuel system to maintain the  
optimal, stoichiometric air fuel ratio. The air fuel mix-  
ture to the engine is controlled by biasing the  
diaphragm in the fuel regulator using vacuum (from the  
carburetor). This vacuum signal is directed to the fuel  
regulator via the control valve. The air fuel ratio con-  
troller determines the amount of vacuum signal sent to  
the fuel regulator. The more vacuum sent to the regula-  
tor, the more restricted the fuel flow will be, therefore  
the leaner the air fuel mixture.  
®
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Section 2 — Installation  
Guardian Liquid-cooled 40 kW Generator  
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 (such as the Generac “GTS” type 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.  
OTHER PUBLISHED STANDARDS  
In addition to NFPA standards, the following informa-  
tion pertaining to the installation and use of standby  
electric systems is available:  
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.  
• 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 MAINTE-  
NANCE 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 SYS-  
TEMS, available from the American National  
Standard Institute, 1430 Broadway, New York, N.Y.  
10018.  
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 per-  
taining to the installation.  
This genset must be installed on a level surface. The  
base frame must be level within two (2) inches all  
around.  
After the system has been installed, you must not do  
anything that might render the installation in noncom-  
pliance with such codes, standards and regulations.  
NOTE:  
• NEC HANDBOOK available from the National Fire  
Protection Association, 1 Batterymarch Park,  
PO Box 9146, Quincy, MA 02269-9959.  
For more information about the installation of a stand-  
by system, you can order Engine-Generator Standby  
Electric Power Systems Installer’s Guide and  
Reference Manual (part #046622) from a Generac  
Authorized Service Dealer.  
2.1 BASIC STANDBY ELECTRIC SYSTEM  
Figure 2.1 shows a schematic diagram of a basic stand-  
by 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:  
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:  
• Permits the LOAD circuits to be connected to only one  
power supply at a time.  
• Prevents electrical backfeed between STANDBY  
power and the UTILITY power circuits.  
• NFPA No. 37, STATIONARY COMBUSTION ENGINES  
AND GAS TURBINES.  
Notice that both the STANDBY and the UTILITY power  
supplies to the transfer switch are protected against  
overload by a main line circuit breaker.  
• 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.  
NOTE:  
Generac recommends the use of a Generac Power  
Systems “pre-packaged” type transfer switch (Part  
No. 0D4406) in conjunction with this generator.  
• NFPA No. 10, INSTALLATION, MAINTENANCE AND  
USE OF PORTABLE FIRE EXTINGUISHERS.  
®
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Section 2 — Installation  
Guardian Liquid-cooled 40 kW Generator  
Figure 2.1 – Basic Standby Electric System  
DANGER  
Do not connect the ground wire to any pipe that  
carries a flammable or explosive substance – FIRE  
or an EXPLOSION may result.  
Proper grounding helps protect personnel against electri-  
cal 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)  
2.2 EMERGENCY CIRCUIT ISOLATION  
METHOD  
This prevents overloading the generator by keeping elec-  
trical loads below the wattage/amperage capacity of the  
generator. If the generator is powering only critical  
loads, within its wattage/amperage capacity, during util-  
ity power outages, consider using the emergency circuit  
isolation method.  
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 gener-  
2.5 GENERATOR AC NEUTRAL  
CONNECTIONS  
ator. The transfer switch must meet the following Generac uses an UNGROUNDED AC neutral. Grounding  
requirements:  
is recommended only at the main service entrance.  
• It must have an ampere rating equal to or greater  
than the total amperage rating of the emergency dis-  
tribution panel circuit.  
2.6 TRANSFER SWITCH START SIGNAL  
CONNECTIONS  
• It must be installed between the building’s main distri-  
2.6.1 PRE-PACKAGED TYPE SWITCH  
bution panel and the emergency distribution panel.  
Connect the six signal wires from the automatic trans-  
fer switch to the engine generator control, which is  
located on the upper right side and inside the lower  
control panel. Match wires 23, 194, N1, N2, T1 and T2  
in the transfer switch to the corresponding wires on the  
terminal strip in the lower panel. The conductors for  
these wires should be in a seperate conduit from the  
main AC output wires. If the control wires are run in the  
same conduit, the control wires must be a shielded  
cable.  
2.3 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 genera-  
tor 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 must be installed between the  
utility service entrance and the building distribution  
panel.  
2.6.2 “GTS” Type Engineered Switch  
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 lower panel.  
Match wires 178 and 183 in the transfer switch to 178  
and 183 on the terminal strip in the control panel. The  
2.4 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 conductors for the two-wire start circuit must be in their  
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 your area. Grounding procedures must  
meet local regulations.  
own conduit. If the control wires are run in the same  
conduit, the control wires must be a shielded cable.  
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Section 2 — Installation  
Guardian Liquid-cooled 40 kW Generator  
NOTE:  
2.7.1 VENTED BATTERIES  
When using a GTS switch, it is necessary to connect  
a 240V AC supply to N1 and N2 terminals  
of the generator to provide for battery charging.  
Wires T1, T2, 23 and 194 should not be  
connected.  
The electrolyte is a dilute sulfuric acid that is  
harmful to the skin and eyes. It is electrically con-  
ductive and corrosive. The following procedures  
are to be observed:  
!
2.7 BATTERY INSTALLATION  
• 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 atten-  
tion, 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.  
DANGER  
Standby generators installed with automatic trans-  
fer 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 per-  
sonnel, do not connect battery cables until the  
normal source voltage at the transfer switch is cor-  
rect and the system is ready to be placed 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 bat-  
tery 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.  
Lead acid batteries present a risk of fire because  
they generate hydrogen gas. The following proce-  
dures 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.  
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 fluid is spilled, flush the affected area  
immediately with clear water.  
!
For recommended batteries, see Section 4.5, “Battery  
Maintenance”. 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 neces-  
sary to check the specific gravity or electrolyte level.  
Have these procedures performed at the intervals spec-  
ified in Section 4, “Maintenance.” A negative ground sys-  
tem 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.  
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.  
NOTE:  
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.  
Damage will result if the battery connections are  
reversed.  
2.8 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 safe-  
ty information in this manual, before attempting to oper-  
ate this (and related) equipment.  
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Section 2 — Installation  
Guardian Liquid-cooled 40 kW Generator  
2.8.1 PRIOR TO INITIAL START-UP  
2.8.6 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 approx-  
imately 22 pounds (10 kg), applied midway between  
pulleys, deflects the belt about 3/8- to 5/8-inch (10 to 16  
mm).  
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 quanti-  
ties of engine fluids (oil, coolant, fuel, etc.) may  
result in an engine failure.  
!
2.8.7 ELECTRICAL SYSTEM  
Before starting the generator for the first time, the  
installer must complete the following procedures. For  
follow-up maintenance information and/or service inter-  
vals, please refer to Section 4, “Maintenance.”  
Make sure the generator is properly connected to an  
approved earth ground and/or ground rod.  
Make sure the generator battery is fully charged, proper-  
ly installed and interconnected, and ready for use.  
Check to ensure that there are no loose electrical con-  
nections. Restrain any loose wires to keep them clear of  
any moving generator set components.  
2.8.2 TRANSFER SWITCH  
If this generator is used to supply power to any electri-  
cal 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 compli-  
ance with applicable codes, standards and regulations.  
2.8.8 RODENT PROTECTION  
Make sure the four 3-inch diameter cap plugs (part #  
0A8785) are properly installed in the tie-down holes in  
the side rails of the unit’s base frame (Figure 2.3). The  
cap plugs are shipped in a plastic bag located in the  
lower connection box. These plugs are needed to pre-  
vent rodents from accessing the interior of the genera-  
tor set. On acoustic units, cap plugs also are needed to  
stay within noise specification limits.  
2.8.3 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 Section 1.8,  
“Specifications”, for more information.  
Figure 2.3 - Base Frame Cap Plugs  
2.8.4 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 Section 1.8,  
“Specifications” and Section 1.10, “Engine Oil  
Recommendations”.  
NOTE:  
This engine is shipped from the manufacturer with  
SAE 15W-40 oil. This oil should be changed after 30  
hours of operation.  
2.8.5 ENGINE COOLANT  
Have the engine cooling system properly filled with the  
recommended coolant mixture. Check the system for  
leaks and other problems. See Section 1.8,  
“Specifications” and Section 1.11, “Coolant”.  
®
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Section 3 — Operation  
Guardian Liquid-cooled 40 kW Generator  
3.1.6 AUTO/OFF/MANUAL SWITCH  
See Section 3.2.  
3.1 CONTROL CONSOLE COMPONENTS  
The components of a liquid-cooled generator control  
console (Figure 3.1) are as follows:  
3.1.7 FAULT INDICATOR LAMP  
Figure 3.1 – Control Console  
This 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  
3.1.8 15-AMP FUSE  
This fuse protects the control console’s DC control cir-  
cuit against electrical overload. If the fuse has melted  
open because of an overload, engine cranking and start-  
up cannot occur. Replace the fuse with an identical AGC  
15-amp replacement fuse.  
15  
3.1.9 7.5 AMP INLINE FUSE (NOT SHOWN)  
3.1.1 AC VOLTMETER  
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.  
The voltmeter displays generator AC output voltage dur-  
ing operation. Voltage is regulated by a solid-state volt-  
age regulator and is proportional to AC frequency. Refer  
to the unit’s DATA PLATE for rated AC voltage.  
3.1.2 AC AMMETER  
This indicates current draw of connected electrical  
loads during operation. DO NOT EXCEED THE UNIT’S  
RATED MAXIMUM CONTINUOUS CURRENT. Refer to  
the unit DATA PLATE.  
3.1.10 VOLTAGE-PHASE SELECTOR SWITCH  
This switch permits selection between either line-to-line  
or line-to-neutral voltage and amperage readings on the  
console AC voltmeter and AC ammeter.  
3.1.3 AC FREQUENCY METER  
3.1.11 SET EXERCISE TIME SWITCH  
This switch allows to program the generator to start and  
exercise automatically. (See Section 3.6)  
This indicates generator AC output frequency in Hertz  
(cycles per second). Frequency is proportional to engine  
speed. Units with a four-pole rotor, supply 60 Hertz at  
1,800 rpm. The frequency reading with no electrical  
loads connected (no-load condition) should be between  
60-62 Hertz.  
3.2 USING THE AUTO/OFF/MANUAL  
SWITCH  
3.1.4 DC VOLTMETER  
3.2.1 “AUTO” POSITION  
The generator is equipped with a belt-driven DC alter-  
nator, which maintains battery state of charge when the  
engine operates. The control module assembly (CMA)  
also incorporates a trickle charge circuit that maintains  
battery state of charge during nonoperating periods.  
Battery voltage should read approximately12.5 to 14.5  
volts DC. A low battery voltage indicates the battery is  
discharging.  
Selecting this switch position activates fully automatic  
system operation. It also allows the unit to start and  
exercise the engine every seven days with the setting of  
the exercise timer.  
3.1.5 HOURMETER  
This indicates the time the engine-generator has operat-  
ed, in hours and tenths of hours. Use the hourmeter  
along with the periodic maintenance schedule for your  
generator set.  
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Section 3 — Operation  
Guardian Liquid-cooled 40 kW Generator  
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.  
3.2.2 “OFF” POSITION  
This switch position shuts down the engine. This posi-  
tion also prevents operation.  
The actual sequence of operation is controlled by  
sensors and timers on a control logic circuit board, as  
follows:  
3.2.3 “MANUAL POSITION  
Set the switch to Manual to crank and start the engine.  
Transfer to standby power will not automatically occur  
unless there is a utility failure.  
A.Utility Voltage Dropout Sensor  
• This sensor monitors utility source voltage.  
• If utility source voltage drops below about 60 per-  
cent of the nominal supply voltage, the sensor ener-  
gizes a 15-second timer.  
• Once the timer has expired, the engine will crank  
and start.  
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 pre-  
vent possible injury that might be caused by such  
sudden starts, always set the switch to OFF and  
remove the fuse 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.  
B.Engine Warm-up Time Delay  
• This mechanism lets the engine warm up for about  
10 seconds before the load is transferred to a stand-  
by 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  
3.3 AUTOMATIC TRANSFER OPERATION  
• This sensor monitors utility power supply voltage.  
When that voltage is restored above 80 percent of  
the nominal source voltage, a retransfer time delay  
starts timing.  
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.  
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.  
E.Retransfer Time Delay  
• This timer runs for about 15 seconds.  
• At end of a 15-second delay, circuit board action de-  
energizes transfer relay in the transfer switch.  
• Retransfer to utility power source then occurs.  
F. Engine Cool-down Timer  
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  
“Sequence of Automatic Operation.”  
• 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 ENGINE HEATER  
This Generac standby generator comes equipped with a  
block heater (Figure 3.2, page 14) that is similar to the  
block heaters used in automotive applications. The  
block heater must be connected to a customer supplied  
120V AC circuit.  
3.4 SEQUENCE OF AUTOMATIC  
OPERATION  
The generator’s control panel houses a control logic cir-  
cuit 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).  
®
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