Generac Power Systems Portable Generator 04389 2 04456 2 04390 2 User Manual

Installation and  
Owner’s Manual  
Air-cooled, Prepackaged  
Automatic Standby Generators  
Models:  
04389-2 (6 kW NG, 7 kW LP)  
04456-2 (12 kW NG, 12 kW LP)  
04390-2 (13 kW NG, 15 kW LP)  
*This manual should remain with the unit.  
Not intended for use as Primary Power in place of utility or  
in life-support applications.  
!
!
DANGER  
DEADLY EXHAUST FUMES. OUTDOOR INSTALLATION ONLY!!  
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Table of Contents  
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators  
Introduction ........................Inside Front Cover  
Section 3 – Operation ....................................14  
3.1 Break-in Procedure......................................14  
3.2 Using the Auto/Off/Manual Switch ..............14  
3.3 Automatic Transfer Operation ....................14  
3.4 Sequence of Automatic Operation................15  
3.5 Manual Transfer Operation ........................15  
3.6 Setting the Exercise Timer ..........................16  
3.7 Protection Systems ......................................16  
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  
Section 4 – Maintenance ..............................17  
4.1 Fuse ............................................................17  
4.2 Checking the Engine Oil Level ....................17  
4.3 Changing the Engine Oil ..............................18  
4.4 Changing the Oil Filter ................................18  
4.5 Changing the Engine Air Cleaner ................18  
4.6 Spark Plug(s) ..............................................19  
4.7 Battery Maintenance....................................19  
4.8 Adjusting GH-410/GT-990 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  
4.13 Service Schedule ........................................22  
1.3 NEC Requirement for Arc Fault Circuit  
Interruption Breaker for Bedrooms ..............4  
1.4 The Generator ..............................................5  
1.5 Specifications ................................................6  
1.6 System Set LED ............................................7  
1.7 Fuel Requirements and Recommendations....7  
1.8 Fuel Consumption ........................................7  
1.9 Reconfiguring the Fuel System ......................7  
1.10 Location ........................................................8  
1.11 Battery Installation ........................................9  
1.12 The Battery....................................................9  
Section 2 – Post Installation Start-up  
and Adjustments ......................10  
2.1 Before Initial Startup ..................................10  
2.2 Check Transfer Switch Operation................10  
Section 5 – Troubleshooting ........................23  
5.1 Troubleshooting Guide................................23  
Section 6 – Electrical Data............................24  
Section 7 – Exploded Views and  
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 ......................13  
2.8 Voltage Regulator Adjustment......................13  
Parts Lists....................................32  
Section 8 – Mounting Dimensions..............53  
Section 9 – Notes ............................................54  
Section 10 – Warranty....................................56  
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IMPORTANT SAFETY INSTRUCTIONS  
Guardian 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.  
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GENERAL HAZARDS  
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 an Authorized  
Guardian 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 sys-  
tem must be installed properly, in strict compli-  
ance with applicable codes and standards.  
Following installation, do nothing that might ren-  
der 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 seri-  
ously 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 Guardian Authorized Dealer for parts  
needing repair or replacement.  
• Before performing any maintenance on the genera-  
tor, disconnect its battery cables to prevent acci-  
dental start up. Disconnect the cable from the bat-  
tery 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 con-  
ditions from leaking exhaust gases, fuel leakage,  
oil leakage, etc.  
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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 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 precau-  
tions.  
Generac cannot possibly anticipate any or all  
circumstances 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 tech-  
nique Generac does not specifically recommend,  
ensure that it is safe for others. Also make sure the  
procedure, work method or operating technique cho-  
sen does not render the generator unsafe.  
DANGER  
Despite the safe design of this generator,  
!
operating this equipment imprudently, neglecting  
its maintenance or being careless can cause  
possible injury or death. Permit only responsible  
and capable persons to 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.  
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IMPORTANT SAFETY INSTRUCTIONS  
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators  
• 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 extin-  
guisher properly charged and be familiar with its  
use. Consult the local fire department with any  
questions pertaining to fire extinguishers.  
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 opera-  
tion. Avoid contact with bare wires, terminals, con-  
nections, 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 sys-  
tem, 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, imme-  
diately 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 equip-  
ment. Jewelry can conduct electricity resulting in  
electric shock, or may get caught in moving com-  
ponents causing injury.  
EXPLOSION HAZARDS  
• Do not smoke around the generator. Wipe up any  
fuel or oil spills immediately. Ensure that no com-  
bustible materials are left in the generator com-  
partment, or on or near the generator, as FIRE or  
EXPLOSION may result. Keep the area surround-  
ing 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 applica-  
ble fuel-gas codes. Before placing the home stand-  
by 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, regula-  
tions 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, avail-  
able 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 SYS-  
TEMS, available from the American Society of  
Agricultural Engineers, 2950 Niles Road, St.  
Joseph, MI 49085.  
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 installa-  
tion, do nothing that might alter a safe installation  
and render the unit in noncompliance with the  
aforementioned codes, standards, laws and regu-  
lations.  
9. NFPA No. 30, FLAMMABLE AND COMBUSTIBLE  
LIQUIDS CODE, available same as Item 1.  
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Section 1 — General Information  
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators  
There are LED readouts on the control panel to noti-  
DANGER  
fy personnel that one of these faults has occurred.  
There is also a “System Set” LED that is lit when all  
of the conditions describe in Section 1.3 are true.  
Only qualified electricians or contractors should  
attempt such installations, which must comply  
strictly with applicable codes, standards and  
regulations.  
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1.3 NEC REQUIREMENT FOR ARC  
FAULT CIRCUIT INTERRUPTION  
1.1 UNPACKING/INSPECTION  
After unpacking, carefully inspect the contents  
for damage.  
BREAKER FOR BEDROOMS  
In 2001, the National Electric Code (NEC) introduced  
a requirement for new construction. This new  
requirement indicates the need for Arc Fault Circuit  
Interrupters to be used to protect the complete  
branch circuit that feeds a dwelling bedroom. The  
actual NEC requirement is indicated below.  
• This standby generator set has been factory sup-  
plied with a weather protective enclosure that is  
intended for outdoor installation only.  
• This standby generator set is packaged with an  
automatic transfer switch with built in load center.  
The combination transfer switch and load center is  
pre-wired with a two foot and 30 foot conduit.  
Circuit breakers for emergency circuit connections  
are included.  
1.3.1 SECTION 210.12 ARC FAULT CIRCUIT  
INTERRUPTER PROTECTION  
1. Definition: An arc fault circuit interrupter is a  
device intended to provide protection from the  
effects of arc faults by recognizing characteristics  
unique to arcing and by functioning to de-ener-  
gize the circuit when an arc fault is detected.  
2. Dwelling Unit Bedrooms: All branch circuits that  
supply 125 volt, single-phase, 15 and 20 ampere  
outlets installed in dwelling unit bedrooms shall  
be protected by an arc fault circuit interrupter  
listed to provide protection of the entire branch  
circuit.  
Section 210.12 requires that AFCI protection be pro-  
vided on branch circuits that supply outlets (recepta-  
cle, lighting, etc.) in dwelling bedrooms. The require-  
ment is limited to 15 and 20 ampere, 125 volt cir-  
cuits. There is no prohibition against providing AFCI  
protection on other circuits or in locations other than  
bedrooms. Because circuits are often shared between  
a bedroom and other areas such as closets and hall-  
ways, providing AFCI protection on the complete cir-  
cuit would comply with 210.12.  
• This UL listed, 2-pole switch is rated at 100 AC  
amperes at 250 volts maximum. This transfer  
switch is for indoor use 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 trans-  
fer switch. The transfer switch must effectively  
isolate the electrical system from the utility dis-  
tribution system when the generator is operat-  
ing (NEC 700, 701 & 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 their signature under the con-  
signor's memo of loss or damage.  
If during the installation of the Guardian Home  
Standby system the decision is made to provide back  
up power to a bedroom branch circuit, then the cir-  
cuit breaker in the Guardian Transfer Switch should  
be replaced with an Arc Fault Circuit Interrupter.  
If a loss or damage is noted 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.  
It is most important that breakers only be switched  
like for like. For instance, if replacing a 15A breaker,  
it MUST be replaced with a 15A AFCI breaker.  
Likewise, a 20A breaker MUST be replaced with a  
20A AFCI.  
1.2 PROTECTION SYSTEMS  
Unlike an automobile engine, the generator may have  
to run for long periods of time with no operator pres-  
ent to monitor engine conditions. For that reason, the  
engine is equipped with the following systems that  
protect it against potentially damaging conditions:  
These AFCI breakers are available at the nearest  
Home Depot or hardware store.  
Siemens Item #  
Q115AF  
Description  
1. Low Oil Pressure Sensor  
2. High Temperature Sensor  
3. Overcrank  
4. Overspeed  
15A Single Pole AFCI  
20A Single Pole AFCI  
Q120AF  
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Section 1 — General Information  
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators  
1.4 THE GENERATOR  
Figure 1.1 – 7 kW, Single Cylinder GH-410 Engine  
Oil Check/Fill  
Data Decal  
Control Panel  
Air Filter  
Exhaust  
Enclosure  
Fuel Regulator  
Fuel Inlet  
Battery Compartment  
Oil Filter  
Figure 1.2 – 12 kW and 15 kW, V-twin GT-990 Engine  
Data  
Decal  
Control  
Panel  
Oil Dipstick  
Air Filter  
Exhaust  
Enclosure  
Fuel Regulator  
Fuel Inlet  
Battery Compartment  
Oil Filter  
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Section 1 — General Information  
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators  
1.5 SPECIFICATIONS  
1.5.1 GENERATOR  
Model 04389-2  
6,000 NG/7,000 LP  
120/240  
Model 04456-2  
12,000 NG/12,000 LP 13,000 NG/15,000 LP†  
Model 04390-2  
Rated Max. Continuous Power Capacity (Watts*)  
Rated Voltage  
120/240  
120/240  
Rated Max. Continuous Load Current (Amps)  
120 Volts**  
50.0 NG/58.3 LP  
100.0 NG/100.0 LP  
108.3 NG/125.0 LP  
240 Volts  
25.0 NG/29.2 LP  
50.0 NG/50.0 LP  
54.2 NG/62.5 LP  
Main Line Circuit Breaker  
Phase  
Number of Rotor Poles  
Rated AC Frequency  
Power Factor  
30 Amp  
50 Amp  
60 Amp/70 Amp†  
1
2
1
2
1
2
60 Hz  
1
60 Hz  
1
60 Hz  
1
Recommended Air Filter  
Battery Requirement  
Generac Part # C8127 Generac Part # C8127 Generac Part # C8127  
Group 26/26R  
12 Volts and  
Group 26/26R  
12 Volts and  
Group 26/26R  
12 Volts and  
350 Cold-cranking  
Amperes Minimum  
550 Cold-cranking  
Amperes Minimum  
550 Cold-cranking  
Amperes Minimum  
Weight  
452 Pounds  
68 db (A)  
470 Pounds  
70.5db (A)  
-20°F (-28.8°C) to 104°F (40°C)  
487 Pounds  
71.5 db (A)  
Output Sound Level @ 23 ft (7m) at full load  
Normal Operating Range  
* 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 (10° F) above 16° C (60° F) ambient temperature.  
** Load current values shown for 120 volts are maximum TOTAL values for two separate circuits. The maximum current in each circuit must not exceed the value stated for 240 volts.  
† 15,000 watt with upgrade kit 04578-1. Kit includes power harnesses and 70 amp 2-pole circuit breaker.  
1.5.2 ENGINE  
Model 04389-2  
GH-410  
Model 04456-2  
GT-990  
Model 04390-2  
GT-990  
Type of Engine  
Number of Cylinders  
Rated Horsepower  
Displacement  
1
2
2
14.5 @ 3,600 rpm  
410cc  
26 @ 3,600 rpm  
992cc  
30 @ 3,600 rpm  
992cc  
Cylinder Block  
Aluminum w/Cast  
Iron Sleeve  
Aluminum w/Cast  
Iron Sleeve  
Aluminum w/Cast  
Iron Sleeve  
Valve Arrangement  
Ignition System  
Recommended Spark Plug  
Spark Plug Gap  
Overhead Valves  
Solid-state w/Magneto  
RC12YC  
Overhead Valves  
Solid-state w/Magneto  
RC12YC  
Overhead Valves  
Solid-state w/Magneto  
RC12YC  
0.76 mm (0.030 inch) 0.508 mm (0.020 inch) 0.508 mm (0.020 inch)  
Compression Ratio  
Starter  
8.6:1  
12 Vdc  
9.5:1  
12 Vdc  
9.5:1  
12Vdc  
Oil Capacity Including Filter  
Recommended Oil Filter  
Recommended Air Filter  
Operating RPM  
Approx. 1.5 Qts  
Approx. 1.7 Qts  
Approx. 1.7 Qts  
Generac Part # 70185 Generac Part # 70185 Generac Part # 70185  
Generac Part # 0C8127 Generac Part # 0C8127 Generac Part # 0C8127  
3,600  
3,600  
3,600  
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Section 1 — General Information  
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators  
1.6 SYSTEM SET LED  
DANGER  
The “System Set” LED is lit when all of the following  
conditions are true:  
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.  
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 PCB. If the utility sense volt-  
age 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.  
1.9 RECONFIGURING THE  
FUEL SYSTEM  
3. The “Not In Auto” dip switch is set to the OFF  
1.9.1 7 KW, 410CC ENGINE  
position on the control board.  
To reconfigure the fuel system from NG to LP,  
follow these steps:  
4. No alarms are present, for example, low oil pres-  
sure, high temperature, etc.  
1. Turn the main gas supply off.  
1.7 FUEL REQUIREMENTS  
2. Remove the carburetor fuel hose from the outlet  
port of the demand regulator (Figure 1.3).  
3. Disconnect wire #0 and wire #14 from the gas  
solenoid located on the top of the demand regu-  
lator.  
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.  
4. Remove the demand regulator by rotating coun-  
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.  
terclockwise.  
5. Remove the brass hose fitting from the outlet port  
of the demand regulator.  
6. Remove the brass metering jet (loosen counter-  
clockwise) from the housing port of the demand  
regulator located on the side of the regulator.  
7. Install new LP metering jet (tighten clockwise) in  
the outlet port of the demand regulator.  
8. Refit the brass hose fittings to the outlet port of  
the demand regulator.  
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.  
9. Reverse procedure steps 1-4 to reinstall demand  
regulator.  
10. Reverse the procedure to convert back to natural  
gas.  
Fuel pressure for both natural gas and liquid  
propane set ups should be 11 inches to 14 inches  
of water column (0.4 to 0.5 psi) at all load ranges.  
Figure 1.3 – Demand Regulator  
NOTE:  
FUEL HOSE  
A separate gas line and regulator may be needed  
to assure proper gas pressure (11-14”) to the gen-  
erator. Low gas pressure can cause hard starting  
and could affect engine durability.  
BRASS HOSE  
FITTING  
FUEL HOSE  
BRASS HOSE  
FITTING  
OUTLET  
PORT  
FUEL JET  
REGULATOR  
HOUSING PORT  
1.8 FUEL CONSUMPTION  
Model #  
Nat. Gas (*)  
LP Vapor (**)  
1/2 Load Full Load 1/2 Load  
Full Load  
1.21/44.1  
2.17/79.0  
2.80/102.3  
04389  
04456  
04390  
74  
105  
185  
240  
0.91/33  
1.34/48.9  
1.73/63.2  
114  
148.5  
NG FUEL SYSTEM  
LP FUEL SYSTEM  
*Natural gas is in cubic feet per hour.  
**LP is in gallons per hour/cubic feet per hour.  
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Section 1 — General Information  
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators  
NOTE:  
14. It may be necessary to make minor adjustments  
to the preset adjustment screw settings to achieve  
maximum power. If experiencing problems with  
the unit producing maximum power, follow the  
procedure in Section 2.6 (Adjusting the Fuel  
Regulator).  
The natural gas adjustment screw is preset during  
installation and should not need any further  
adjustment.  
1.9.2 12KW AND 15KW, 990CC ENGINES  
Figure 1.4 - Demand Regulator  
To reconfigure the fuel system from NG to LP,  
follow these steps:  
OUTLET PORTS  
FUEL HOSE  
NOTE:  
BRASS HOSE  
FITTING  
The primary regulator for the propane supply is  
NOT INCLUDED with the generator. A fuel pres-  
sure of 11 to 14 inches of water column (0.6 psi)  
to the fuel inlet of the generator MUST BE SUP-  
PLIED.  
IDLE CIRCUIT  
PORT  
BRASS HOSE  
FITTING  
SMALL  
FUEL JET  
1
NP  
REGULATOR  
HOUSING PORT  
ADJUSTER  
SCREWS  
1. Turn OFF the main gas supply.  
2. Remove the engine air in baffle located on the left  
hand 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.  
3. 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 screw driver to gen-  
tly lift up the hose edge.  
1.10 LOCATION  
1.10.1 GENERATOR  
Install the generator set, in its protective enclosure,  
outdoors, where adequate cooling and ventilating air  
is always available. Consider these factors:  
4. Remove the brass hose fitting screwed into the  
fuel regulator.  
• 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 drift-  
ing, 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.  
5. Locate and identify the brass idle jet. This will be  
located in the fuel regulator casting facing the  
front of the unit.  
6. Remove the idle jet from its holding location.  
7. Place the idle jet, thread side first, into the  
threaded hole originally occupied by the brass  
hose fitting.  
8. Using a short No. 2 Phillips screw driver, thread  
the idle jet into the regulator casting. DO NOT  
OVER TIGHTEN.  
9. Apply thread sealant to the threads of the hose fit-  
ting and replace it into the regulator body.  
10. Re-attach the small hose and hose clamp and  
tighten as necessary.  
• 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 DIS-  
TANCE.  
The genset must be installed on a level surface. The  
base frame must be level within two (2) inches all  
around.  
11. Replace the engine air in baffle using the four M6  
screws.  
12. Identify both brass adjustment screws on the reg-  
ulator.  
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.  
1.10.2 TRANSFER SWITCH  
1.10.2.1 7 kW, 12 kW and 15 kW Units  
13. To adjust the system to run on LP fuel, turn the  
adjuster screw that can be accessed from inside  
the front of the unit, ¼ TURN CLOCKWISE. This  
should now set the system for maximum power  
The transfer switch shipped with this generator is  
enclosed in a NEMA 1 enclosure. This type of enclo-  
sure is intended for indoor use only. Follow these  
rules:  
and best performance.  
®
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Section 1 — General Information  
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators  
• Install the transfer switch indoors on a firm, stur-  
5. Connect the black battery cable (from frame  
ground) to the battery post indicated by a nega-  
tive, NEG or (—).  
dy supporting structure.  
To prevent switch distortion, level the switch if nec-  
essary. This can be done by placing washers  
between the switch enclosure and mounting sur-  
face.  
• 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.  
NOTE:  
Damage will result if battery connections are made  
in reverse.  
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 BATTERY INSTALLATION  
Fill the battery with the proper electrolyte fluid if nec-  
essary 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.  
1.12 THE BATTERY  
2. Turn off utility power supply to the transfer  
Servicing of the battery is to be performed or super-  
vised by personnel knowledgeable of batteries and  
the required precautions. Keep unauthorized person-  
nel away from batteries.  
switch.  
3. Remove the 5A and 15A fuses from the generator  
control panel.  
When replacing the battery, use the following type of  
battery: Group 26/26R 12-volt DC, negative ground  
battery with a rating of 350 cold-cranking amps min-  
imum for 7 kW; 550 cold-cranking amps minimum  
for 12 and 15 kW at -17.8º C (0º F) minimum. When  
using a maintenance-free 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 connect-  
ed and terminals are tight. Observe battery polarity  
when connecting the battery to the generator set.  
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 connect-  
ed. 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 genera-  
tor (Figure 1.5). Connect cables to battery posts as  
follows:  
Figure 1.5 – Battery Cable Connections  
DANGER  
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 the 5A and 15A fuses from the generator  
control panel.  
• 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.  
4. Connect the red battery cable (from starter con-  
tactor) to the battery post indicated by a positive,  
POS or (+).  
®
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Section 2 — Post Installation Start-up and Adjustments  
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators  
5. 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.  
Do not open or mutilate the battery. Released  
electrolyte has been known to be harmful to  
the skin and eyes, and to be toxic.  
!
!
6. 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.  
The electrolyte is a dilute sulfuric acid that is  
harmful to the skin and eyes. It is electrically  
conductive and corrosive.  
The following procedures are to be observed:  
• Wear full eye protection and protective clothing;  
• Where electrolyte contacts the skin, wash it off  
immediately with water;  
• Where electrolyte contacts the eyes, flush  
thoroughly and immediately with water and seek  
medical attention; and  
• Spilled electrolyte is to be washed down with an  
acid neutralizing agent. A common practice is to  
use a solution of 1 pound (500 grams) bicarbonate  
of soda to 1 gallon (4 liters) of water. The bicar-  
bonate 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.  
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 man-  
ual operation procedures.  
DANGER  
Do not attempt manual transfer switch opera-  
tion 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.  
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 touch-  
ing the battery by first touching a grounded metal  
surface.  
2.3 ELECTRICAL CHECKS  
Complete electrical checks as follows:  
1. Set the generator's main circuit breaker to its  
OFF (or open) position.  
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.  
2. Set the generator's AUTO/OFF/MANUAL switch to  
the OFF position.  
3. Turn OFF all loads connected to the transfer  
switch terminals T1 and T2.  
4. Turn on the utility power supply to the transfer  
switch using the means provided (such as a utili-  
ty main line circuit breaker).  
Be sure the utility power supply is turned off  
and the 5A and 15A fuses are removed from  
the generator control panel, or sparking may  
occur at the battery posts as the cables are  
attached and cause an explosion.  
DANGER  
2.1 BEFORE INITIAL START-UP  
The transfer switch is now electrically “hot.”  
Contact with “hot” parts will result in extreme-  
ly hazardous and possibly fatal electrical shock.  
Proceed with caution.  
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  
5. Use an accurate AC voltmeter to check utility  
power source voltage across transfer switch ter-  
minals N1 and N2. Nominal line-to-line voltage  
should be 240 volts AC.  
6. Check utility power source voltage across termi-  
nals N1 and the transfer switch neutral lug; then  
across terminal N2 and neutral. Nominal line-to-  
neutral voltage should be 120 volts AC.  
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. Turn OFF all loads connected to the transfer  
switch terminals T1 and T2.  
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Section 2 — Post Installation Start-up and Adjustments  
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators  
7. When certain that utility supply voltage is com-  
patible with transfer switch and load circuit rat-  
ings, turn OFF the utility power supply to the  
transfer switch.  
Do not attempt manual transfer switch opera-  
tion 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.  
8. On the generator panel, set the AUTO/OFF/  
MANUAL switch to MANUAL. The engine should  
crank and start.  
9. 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.  
5. 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.  
6. Set the generator's AUTO/OFF/MANUAL switch to  
MANUAL. The engine should crank and start  
immediately.  
DANGER  
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.  
7. Let the engine stabilize and warm up for a few  
minutes.  
8. Set the generator’s main circuit breaker to its ON  
(or closed) position. Loads are now powered by  
the standby generator.  
9. Turn ON electrical loads connected to transfer  
switch T1 and T2. Apply an electrical load equal  
to the full rated wattage/amperage capacity of the  
installed generator.  
10. Connect an accurate AC voltmeter and a frequen-  
cy meter across terminal lugs E1 and E2. Voltage  
should be greater than 230 volts; frequency  
should be greater than 58 Hertz.  
11. 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.  
12. When testing under load is complete, turn OFF  
electrical loads.  
10. Connect an accurate AC voltmeter and a frequen-  
cy meter across transfer switch terminal lugs E1  
and E2. Voltage should be 242-252 volts; fre-  
quency should read about 61-63 Hertz.  
11. Connect the AC voltmeter test leads across termi-  
nal lug E1 and neutral; then across E2 and neu-  
tral. In both cases, voltage reading should be 121-  
126 volts AC.  
12. Set the generator’s main circuit breaker to its  
OFF (or open) position. Let the engine run at no-  
load for a few minutes to stabilize internal engine  
generator temperatures.  
13. 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 cor-  
rect, but voltage is high or low, the generator’s  
voltage regulator requires adjustment.  
13. Set the generator's main circuit breaker to its  
OFF (or open) position.  
14. Let the engine run at no-load for a few minutes.  
15. Set the AUTO/OFF/MANUAL switch to OFF. The  
engine should shut down.  
2.5 CHECKING AUTOMATIC  
2.4 GENERATOR TESTS UNDER LOAD  
To test the generator set with electrical loads applied,  
proceed as follows:  
OPERATION  
To check the system for proper automatic operation,  
proceed as follows:  
1. Set generator’s main circuit breaker to its OFF  
(or open) position.  
1. Set generator’s main circuit breaker to its OFF  
(or open) position.  
2. Turn OFF all loads connected to the transfer  
switch terminals T1 and T2.  
2. Check that the AUTO/OFF/MANUAL switch is set  
to OFF.  
3. Set the generator's AUTO/OFF/MANUAL switch to  
OFF.  
4. Turn OFF the utility power supply to the transfer  
switch, using the means provided (such as a util-  
ity main line circuit breaker).  
3. Turn OFF the utility power supply to the transfer  
switch, using means provided (such as a utility  
main line circuit breaker).  
4. Manually set the transfer switch to the UTILITY  
position, i.e., load terminals connected to the util-  
ity power source side.  
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Section 2 — Post Installation Start-up and Adjustments  
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators  
5. Turn ON the utility power supply to the transfer  
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  
screws clockwise or counterclockwise one at a  
time until the highest frequency is read on the  
meter. Only limited adjustment is available  
between the set pins (7 kW only). Under no cir-  
cumstances should any of the pins be removed  
(Figures 2.1 and 2.2).  
switch, using the means provided (such as a util-  
ity main line circuit breaker).  
6. Set the AUTO/OFF/MANUAL switch to AUTO. The  
system is now ready for automatic operation.  
7. 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.  
Figure 2.1 — Dual Fuel Regulators  
990  
410  
With the generator running and loads powered by  
generator AC output, turn ON the utility power sup-  
ply to the transfer switch. The following should  
occur:  
Adjustment  
Set  
Pins  
Adjustment  
Screw  
(Both sides)  
Screw  
(One Side  
Only)  
• After about six seconds, the switch should transfer  
loads back to the utility power source.  
• About one minute after retransfer, the engine  
should shut down.  
2.6 ADJUSTING THE REGULATOR  
6. When the highest frequency is reached maximum  
power has been set. From this point turn both  
adjustment screws 1/4 turn counterclockwise.  
The regulator is now set.  
(NATURAL GAS ONLY)  
Although the generator has been factory set to pro-  
vide 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.  
Figure 2.2 — Placement of Regulator  
If experiencing engine problems at high or full load  
conditions follow these steps. It will require a fre-  
quency 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 posi-  
tion.  
2. Allow the generator to start. Before loading the  
generator, confirm that the No Load Frequency,  
with the roof open and door off, is set to 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:  
Adjustment Screw  
Unit  
7 kW  
12 kW  
13 kW  
120 Volts  
50.0 amps  
100.0 amps  
108.3 amps  
240 Volts  
25.0 amps  
50.0 amps  
54.1 amps  
7. Turn utility power to the main distribution panel  
back on. This can be done by switching the serv-  
ice main breaker to the on or closed position.  
Allow the generator to shut down.  
4. When full load has been achieved. Connect a fre-  
quency meter to the output lugs of the generator’s  
main line circuit breaker.  
Do not make any unnecessary adjustments.  
Factory settings are correct for most applica-  
!
tions. However, when making adjustments, be  
careful to avoid overspeeding the engine.  
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