Generac Power Systems Portable Generator 004988 2 User Manual

Owner’s Manual  
Liquid-cooled, Prepackaged  
Standby Generators  
Model Number: 004988-2  
This manual should remain with the unit.  
ONLY QUALIFIED ELECTRICIANS OR CONTRACTORS  
SHOULD ATTEMPT INSTALLATION!!  
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Table of Contents  
Guardian Liquid-cooled 27 kW and 30 kW Generators  
INTRODUCTION................................................IFC  
SAFETY RULES....................................................2  
Section 3 OPERATION ................................12  
3.1 Using a Standard “GTS” Transfer Switch............12  
3.2 Control Console Components..............................13  
3.3 Manual Transfer and Startup..............................14  
3.4 Engine Governor Adjustments ............................14  
3.5 Retransfer and Shutdown....................................14  
3.6 Automatic Operation ..........................................14  
3.7 Weekly Exercise Cycle..........................................14  
Section 4 — MAINTENANCE ..........................15  
Section 1 — GENERAL INFORMATION ............4  
1.1 Generator..............................................................4  
1.2 Transfer Switch ....................................................4  
1.3 Automatic System Operation ................................4  
1.4 Generator AC Connection Systems........................4  
1.5 Main Circuit Breaker ............................................4  
1.6 Generator Fuel System..........................................5  
1.7 Engine Protective Devices......................................5  
1.8 Unpacking ............................................................6  
1.9 Lifting the Generator ............................................6  
1.10 Specifications ........................................................7  
1.11 Fuel Consumption ................................................7  
1.12 Reconfiguring the Fuel System ..............................7  
1.13 Torque Specifications............................................8  
1.14 Engine Oil Recommendations ..............................8  
1.15 Coolant Recommendations....................................8  
1.16 Before Installation ................................................8  
Section 2 — INSTALLATION ............................8  
2.1 Standby Generator Installation ............................8  
2.2 Generator Location................................................9  
2.3 Generator Mounting and Support ........................9  
2.4 Basic Standby Electric System..............................9  
2.5 Emergency Circuit Isolation Method....................10  
2.6 Total Circuit Isolation Method ............................10  
2.7 Grounding the Generator ....................................10  
2.8 Generator AC Neutral Connections......................10  
2.9 Transfer Switch Start Signal Connections ..........10  
2.10 Battery Installation..............................................11  
2.11 Preparation Before Start-Up................................11  
4.1 Maintenance Performed by Authorized  
Service Facilities..................................................15  
4.2 Cooling System....................................................15  
4.3 Overload Protection for Engine DC  
Electrical System ................................................15  
4.4 Checking Fluid Levels ........................................16  
4.5 Maintenance Owner/Operator  
Can Perform........................................................16  
4.6 Miscellaneous Maintenance ................................18  
4.7 Scheduled Maintenance ......................................20  
Section 5 — TROUBLESHOOTING ..................23  
Section 6 — NOTES ........................................24  
Section 7 — INTALLATION DIAGRAM ............25  
Section 8 — ELECTRICAL DATA ....................26  
Section 9 — EXPLODED VIEWS AND  
PARTS LISTS ..............................30  
Section 10 — WARRANTY .................Back Cover  
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IMPORTANT SAFETY INSTRUCTIONS  
Guardian Liquid-cooled 27 kW and 30 kW Generators  
SAVE THESE INSTRUCTIONS – The manufacturer suggests that these rules for safe  
operation be copied and posted in potential hazard areas. Safety should be stressed to all  
operators, potential operators, and service and repair technicians for this equipment.  
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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  
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 this  
equipment be installed, serviced and repaired by a  
Generac Authorized Service Dealer or other compe-  
tent, qualified electrician or installation technician  
who is familiar with applicable codes, standards and  
regulations. The operator also must comply with all  
such codes, standards and regulations.  
• Installation, operation, servicing and repair of this  
(and related) equipment must always comply with  
applicable codes, standards, laws and regulations.  
Adhere strictly to local, state and national electrical  
and building codes. Comply with regulations the  
Occupational Safety and Health Administration  
(OSHA) has established. Also, ensure that the gener-  
ator is installed, operated and serviced in accordance  
with the manufacturer’s instructions and recommen-  
dations. Following installation, do nothing that might  
render the unit unsafe or in noncompliance with the  
aforementioned codes, standards, laws and regula-  
tions.  
• The engine exhaust fumes contain carbon monoxide  
gas, which can be DEADLY. This dangerous gas, if  
breathed in sufficient concentrations, can cause  
unconsciousness or even death. For that reason, 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 ventilat-  
ing air is critical to prevent buildup of explosive gases  
and to ensure correct generator operation. Do not  
alter the installation or permit even partial blockage  
of ventilation provisions, as this can seriously affect  
safe operation of the generator.  
!
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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 genera-  
tor can operate safely, efficiently and reliably only if it is  
properly installed, operated and maintained. Many acci-  
dents are caused by failing to follow simple and funda-  
mental rules or precautions.  
Generac cannot anticipate every possible circumstance  
that might involve a hazard. The warnings in this man-  
ual, and on tags and decals affixed to the unit are, there-  
fore, not all-inclusive. If using a procedure, work  
method or operating technique that Generac does not  
specifically recommend, ensure that it is safe for others.  
Also make sure the procedure, work method or operat-  
ing technique utilized does not render the generator  
unsafe.  
DANGER  
Despite the safe design of this generator,  
!
operating this equipment imprudently, neglecting  
its maintenance or being careless can cause  
possible injury or death. Permit only responsible  
and capable persons to install, operate or main-  
tain 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 27 kW and 30 kW Generators  
• Inspect the generator regularly, and promptly repair • Generators installed with an automatic transfer  
or replace all worn, damaged or defective parts using  
switch will crank and start automatically when NOR-  
MAL (UTILITY) source voltage is removed or is below  
an acceptable preset level. To prevent such automat-  
ic 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.  
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.  
• 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 electrical  
shock. Utility power delivers extremely high and dan-  
gerous voltages to the transfer switch as well as the  
standby generator. Avoid contact with bare wires, ter-  
minals, connections, etc., on the generator as well as  
the transfer switch, if applicable. Ensure all appropri-  
ate covers, guards and barriers are in place before  
operating the generator. If work must be done around  
an operating unit, stand on an insulated, dry surface  
to reduce shock hazard.  
• Do not handle any kind of electrical device while  
standing in water, while barefoot, or while hands or  
feet are wet. DANGEROUS ELECTRICAL SHOCK  
MAY RESULT.  
• If people must stand on metal or concrete while  
installing, operating, servicing, adjusting or repairing  
this equipment, place insulative mats over a dry  
wooden platform. Work on the equipment only while  
standing on such insulative mats.  
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), Article 250  
requires the frame and external electrically conduc-  
tive 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 condi-  
tion in the generator set or by static electricity. Never  
disconnect the ground wire.  
• Wire gauge sizes of electrical wiring, cables and cord  
sets must be adequate to handle the maximum elec-  
trical current (ampacity) to which they will be sub-  
jected.  
• 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 generator electric  
system from the electric utility distribution system  
when the generator is operating. Failure to isolate the  
two electric system power sources from each other by  
such means will result in damage to the generator  
and may also result in injury or death to utility power  
workers due to backfeed of electrical energy.  
• Properly ventilate any room or building housing the  
generator to prevent build-up of explosive gas.  
• Do not smoke around the generator. Wipe up any fuel  
or oil spills immediately. Ensure that no combustible  
materials are left in the generator compartment, or  
on or near the generator, as FIRE or EXPLOSION  
may result. Keep the area surrounding the generator  
clean and free from debris.  
• Generac generator sets may operate using one of sev-  
eral types of fuels. All fuel types are potentially FLAM-  
MABLE and/or EXPLOSIVE and should be handled  
with care. Comply with all laws regulating the storage  
and handling of fuels. Inspect the unit’s fuel system  
frequently and correct any leaks immediately. Fuel  
supply lines must be properly installed, purged and  
leak tested according to applicable fuel-gas codes  
before placing this equipment into service.  
• Diesel fuels are highly FLAMMABLE. Gaseous fluids  
such as natural gas and liquid propane (LP) gas are  
extremely EXPLOSIVE. Natural gas is lighter than air,  
and LP gas is heavier than air; install leak detectors  
accordingly.  
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Section 1 - General Information  
Guardian Liquid-cooled 27 kW and 30 kW Generators  
1.1 GENERATOR  
1.3 AUTOMATIC SYSTEM OPERATION  
When this generator, along with a transfer switch, has  
been installed and interconnected, a circuit board in  
the generator panel constantly monitors UTILITY  
power source voltage. Should that voltage drop below  
a preset value, and remain at such a low state for a  
preset amount of time, the generator cranks and  
starts. After the generator starts, the transfer switch  
transfers load circuits so the generator can power  
them.  
This equipment is a liquid-cooled, engine-driven gen-  
erator set. The generator is designed to supply elec-  
trical power that operates critical electrical loads  
during utility power failure. The unit has been facto-  
ry-installed in a weather resistant, all metal enclosure  
and is intended for outdoor installation only. Use this  
generator as a source of electrical power for the oper-  
ation of 120 and/or 240VAC, single-phase loads.  
When UTILITY source voltage has been restored, the  
switch re-transfers back to the UTILITY source volt-  
age and the generator then shuts down.  
If this generator is used to power electrical load  
circuits normally powered by a UTILITY power  
!
Please reference the transfer switch manual for spe-  
cific information.  
source, it is required by code to install a trans-  
fer switch. The transfer switch must effectively  
isolate the electric system from the utility distri-  
bution system when the generator is operating  
(NEC 701). Failure to isolate an electrical system  
by such means results in damage to the genera-  
tor and may also result in injury or even death  
to utility power workers due to backfeed of  
electrical energy.  
1.4 GENERATOR AC CONNECTION  
SYSTEMS  
The generator was shipped from the factory with its  
stator AC output leads connected in a single-phase,  
three-wire generator AC connection system (Figure  
1.1). The stator assembly in this system consists of a  
pair of stationary windings, with two leads brought  
out of each winding. Each single winding can supply  
120VAC, 60 Hertz. When the two windings are con-  
nected in series, a 240VAC, 60 Hertz AC output  
results. Typically the two HOT leads in the circuit are  
wires 11 and 44. The NEUTRAL leads are the junc-  
tion of Wires 22 and 33. The NEUTRAL is not  
grounded.  
1.2 TRANSFER SWITCH  
This generator system may include a matched auto-  
matic transfer switch which is intended to be used in  
conjunction with the Generac generator. It is supplied  
in either a NEMA 1 enclosure or a NEMA 3R enclo-  
sure. The NEMA 1 enclosure is intended for indoor  
use only. The NEMA 3R enclosure is weather proof  
and can be used indoors or outdoors. Follow these  
rules:  
Figure 1.1 - Generator AC Connection System  
• Install the transfer switch on a firm, sturdy sup-  
porting structure.  
To prevent switch distortion, level the switch if nec-  
essary. This can be done by placing washers  
between the switch enclosure and the mounting  
surface.  
• Never install the switch where water or any corro-  
sive substance might drip onto the enclosure.  
• Protect the switch at all times against excessive  
moisture, dust, dirt, lint, construction grit and cor-  
rosive vapors.  
If a transfer switch is not included, one may be pur-  
chased separately from a Generac Authorized Dealer.  
1.5 MAIN CIRCUIT BREAKER  
The generator’s main circuit breaker is included with  
the unit as shipped from the factory. The breaker for  
each unit is described in Figure 1.2.  
Figure 1.2 - Main Circuit Breaker  
Model  
004988-2  
Rating  
27,000 NG  
30,000 LP  
Phase  
Actual Current  
112.5  
C/B Rating*  
Circuit Breaker  
150A QN2  
1
1
150  
150  
125.0  
150A QN2  
* Amp Rating of C/B structured under model.  
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Section 1 - General Information  
Guardian Liquid-cooled 27 kW and 30 kW Generators  
Figure 1.4 - Low Oil Pressure Switch  
1.6 GENERATOR FUEL SYSTEM  
The unit has been factory tested and adjusted using a  
natural gas fuel system. If propane (LP) gas is neces-  
sary, contact an authorized service dealer.  
Fuel pressure for a natural gas set up should be five  
inches to 14 inches of water column (0.18 to 0.5  
psi) at all load ranges.  
Fuel pressure for an LP vapor set up should be 11  
inches to 14 inches of water column (0.4 to 0.5  
psi) at all load ranges.  
NOTE:  
NOTE:  
A seperate gas line and regulator may be needed  
to assure proper gas pressure to the generator.  
Improper gas pressure can cause hard starting and  
affect engine durability.  
The Low Oil Pressure, High Coolant Temperature  
and Low Coolant Level are not monitored for the  
first 10 seconds of engine run time.  
1.7.2 HIGH COOLANT TEMPERATURE  
SWITCH  
Gaseous fuels such as natural and LP (propane)  
gas are highly explosive. Even the slightest  
spark can ignite such fuels and cause an explo-  
sion. 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.  
!
This normally open (N.O.) thermostatic switch has  
sensing tip which is immersed in captive coolant.  
Should coolant temperature exceed about 230°F  
(110°C), the switch contacts close. This causes the  
engine to shut down automatically and turns on the  
high coolant temperature/low coolant level LED  
(Figure 1.5).  
1.7 ENGINE PROTECTIVE DEVICES  
The engine has several safety switches which cause  
the engine to automatically shut down under the fol-  
lowing conditions: low oil pressure, high coolant tem-  
perature, engine overspeed, low coolant level or over-  
crank (Figure 1.3).  
Figure 1.5- High Coolant Temperature Switch  
Figure 1.3 - Engine Protective Devices  
LOW COOLANT  
LEVEL SWITCH  
LOW OIL  
PRESURE  
SWITCH  
1.7.3 LOW COOLANT LEVEL SWITCH  
HIGH  
COOLANT  
TEMPERATURE  
SWITCH  
Should engine coolant level drop below the level of  
the high coolant temperature switch, it is possible for  
the engine to overheat without automatic shutdown.  
To prevent such overheating without automatic shut  
down, the engine has a low coolant level sensor. If the  
engine coolant drops too low, the engine automatical-  
ly shuts down and turns on the high coolant temper-  
ature/low coolant level LED (Figure 1.6 on page 6).  
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  
operating oil pressure drop below about 8-10 psi  
(55-68 kPa), the switch contacts close, the engine  
shuts down automatically, and the low oil pressure  
LED is turned ON (Figure 1.4).  
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Section 1 — General Information  
Guardian Liquid-cooled 27 kW and 30 kW Generators  
Figure 1.6 - Low Coolant Level Sensor  
1.7.7 LOW BATTERY  
The engine control board continually monitors the  
battery voltage and turns on the low battery LED if  
the battery voltage falls below 11.0 VDC for one  
minute. Low battery voltage is a non-latching alarm,  
which will automatically clear if the battery voltage  
rises above 11.0 VDC.  
The control system will not attempt to start the  
engine if there is a low battery condition, however, if  
the engine is already running when the low battery  
condition occurs, the engine will continue to run as  
long as possible.  
Battery voltage is NOT monitored during the crank  
cycle.  
1.7.4 OVERSPEED SHUTDOWN  
1.7.8 ALARM RESET  
The engine control board receives AC frequency sig-  
nals from an engine run winding in the alternator.  
Should AC frequency exceed about 72 Hertz for three  
seconds or 75 Hertz instantaniously, the engine shuts  
down and the overspeed LED turns on. Should AC  
frequency exceed about 72 Hertz, circuit board action  
will automatically shutdown the engine (Figure 1.7).  
If the engine control board shuts down the generator  
for any of the above reasons, the engine remains  
stopped until the alarm is cleared by placing the  
AUTO/OFF/MANUAL switch into the OFF position.  
1.7.9 DC FUSES  
These fuses are located on the front panel of the con-  
trol system. They protect the panel wiring and com-  
ponents from damaging overload. Always remove the  
15 amp main fuse before working on the generator.  
The unit will not start or crank if this fuse is blown.  
Replace the fuse with one of the same size, type, and  
rating (main AGC-15, battery charger AG4).  
Figure 1.7 - Printed Circuit Board Assembly  
R44  
LED1  
C27  
Q2  
C9  
J2  
C26  
U7  
C4  
D10  
C21  
1.8 UNPACKING  
C30  
C2  
1.8.1 UNPACKING PRECAUTIONS  
RL1  
RL2  
R1  
R48  
D17  
Handle shipping cartons and crates with care. Use  
care to avoid damage from dropping, bumping, colli-  
sion, etc. Store and unpack cartons with the proper  
side up, as noted on the shipping carton.  
R49  
U1  
J1  
L3  
D19  
R E V 9 0 . 6 E 0 4 B #  
1.8.2 INSPECTION  
1.7.5 RPM SENSOR LOSS  
After unpacking, carefully inspect the generator for  
any damage that may have occurred during ship-  
ment. If loss or damage is noted at the time of deliv-  
ery, have the person(s) making delivery note all dam-  
age on the freight bill or affix their signature under  
the consignor’s memo of loss or damage.  
If the engine control board does not receive a proper  
rpm signal from the starter during cranking or run-  
ning, it shuts down the engine on rpm sensor loss  
and flash the overspeed LED.  
1.7.6 OVERCRANK SHUTDOWN  
The engine control board uses a cyclic cranking  
process when attempting to start the engine. The first  
crank cycle is a 15-second crank followed by a seven-  
second rest. This is followed by five more crank  
cycles each with a seven-second crank followed by a  
seven-second rest.  
1.9 LIFTING THE GENERATOR  
When lifting or hoisting equipment is used, be  
careful not to touch overhead power lines. The  
!
generators weight of more than 900 pounds  
requires proper tools, equipment, and qualified  
personnel to be used in all phases of handling  
and unpacking.  
If the engine fails to start after all six attempts, the  
start attempt is stopped and the overcrank LED’s  
illuminated.  
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Section 1 — General Information  
Guardian Liquid-cooled 27 kW and 30 kW Generators  
Fuel pressure for a natural gas set up should be five  
1.10 SPECIFICATIONS  
inches to 14 inches of water column (0.18 to 0.5  
psi) at all load ranges.  
1.10.1 GENERATOR SPECIFICATIONS  
Fuel pressure for an LP vapor set up should be 11  
inches to 14 inches of water column (0.4 to 0.5  
psi) at all load ranges.  
Single-phase  
Model  
004988-2  
Rated Max. Cont.  
27 (NG), 30 (LP)  
1.12 RECONFIGURING THE FUEL  
AC Power Output (kW)  
Rated voltage (volts)  
No. of Rotor Poles  
Driven Speed of Rotor  
Rotor Excitation System  
Type of Stator  
SYSTEM  
120/240  
4
1800  
NOTE:  
All models are configured for natural gas from the  
factory.  
Direct excited brush type  
4 Wire  
To reconfigure the fuel system from NG to LP vapor,  
follow these steps:  
Rotor/Stator Insulation  
Class F/H  
1. Turn the main gas supply off.  
1.10.2 ENGINE SPECIFICATIONS  
2. Remove the carburetor fuel hose from the outlet  
port (Port 1) of the demand regulator (Figure  
1.8).  
Make........................................................................................................Ford  
Displacement ....................................................................................3.0 liters  
Cylinder Arrangement ..............................................................................V-6  
Valve Arrangement................................................................Overhead Valve  
Firing Order ..................................................................................1-4-2-5-3-6  
Number of Main Bearings ............................................................................4  
Compression Ratio ............................................................................9.3 to 1  
No. of Teeth on Flywheel ..........................................................................164  
Ignition Timing at 1800 rpm ..............................................30 degrees BTDC  
Spark Plug Gap ..................................................................0.042-0.046 inch  
Recommended Spark Plugs  
Motor Craft ..........................................................................AG, SF 32PGM  
Oil Pressure ....................................................................................40-50 psi  
Crankcase Oil Capacity ........................................5.0 U.S. quarts (4.7 liters)  
Recommended Engine Oil ..........................................................SAE 5W-20  
Type of Cooling System ..................................Pressurized, closed recovery  
Cooling Fan ................................................................................Pusher Type  
Cooling System Capacity ..................................3.0 U.S. gallons (11.4 liters)  
3. Remove the brass hose fitting from the outlet port  
(Port 1) of the demand regulator.  
4. Remove pipe plug from Port 2.  
5. Install brass hose fitting into Port 2.  
6. Install pipe plug into Port 1.  
7. Connect carburetor gas hose to brass fitting.  
8. Tighten all clamps and plugs.  
9. Make sure fuel supply is of the proper pressure  
and type for configuration.  
10. Reverse the procedure to convert back to natural  
gas.  
Figure 1.8 — Reconfigure the Fuel System  
Port 1  
Port 2  
FUEL HOSE  
FUEL HOSE  
BRASS HOSE  
FITTING  
BRASS HOSE  
FITTING  
Recommended Coolant ............................................Use a 50-50 mixture of  
PLUG  
PLUG  
OUT  
PORT 1  
OUT  
PORT 2  
ethylene glycol base  
and de-ionized water.  
HOUSING  
PORTS  
HOUSING  
PORTS  
1.11 FUEL CONSUMPTION  
Natural Gas:  
% of Load  
25%  
3.1  
50%  
5.9  
75%  
8.5  
100%  
11.0  
3
m /hr  
3
ft /hr  
110.3  
209.0  
299.5  
387.0  
LP Vapor:  
% of Load  
NG FUEL SYSTEM  
LP FUEL SYSTEM  
25%  
1.3  
50%  
2.4  
75%  
3.5  
100%  
4.5  
3
m /hr  
NOTE:  
3
ft /hr  
45.6  
86.4  
123.8  
160.0  
Port 1 is for NG only and Port 2 is for LP vapor  
only. No provision for dual fuel has been made.  
NOTE:  
Fuel consumption is given at rated maximum con-  
tinuous power output when using natural gas rated  
at 1000 Btu per cubic foot. LP gas is rated at 2520  
Btu per cubic foot. Actual fuel consumption  
obtained may vary depending on such variables as  
applied load, ambient temperature, engine condi-  
tions and other environmental factors.  
DANGER  
Serious injury or damage may occur if not con-  
figured properly. Please consult an authorized  
!
Generac Service Dealer with any questions.  
®
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Section 2 — Installation  
Guardian Liquid-cooled 27 kW and 30 kW Generators  
The generator’s rated wattage/amperage capacity  
1.13 TORQUE SPECIFICATIONS  
must be adequate to handle all electrical loads that  
the unit will power. The critical (essential) loads may  
need to be grouped together and wired into a sepa-  
rate “emergency” distribution panel.  
Cylinder Head ............................................15 (+ 90° + 90°) ft.lb.  
Intake Manifold ................................................................13 ft.lb.  
Exhaust Manifold..............................................................13 ft.lb.  
This generator can be installed in conjunction with  
an engineered Generac “GTS” type transfer switch, if  
necessary.  
1.14 ENGINE OIL RECOMMENDATIONS  
The unit has been filled with 5W-20 engine oil at the  
factory. Use a high-quality detergent oil classified “For  
Service CC, SD, SE, SF.” Detergent oils keep the engine  
cleaner and reduce carbon deposits. Use oil having the  
following SAE viscosity rating, based on the ambient  
temperature range anticipated before the next oil  
change:  
The standard transfer switch has no sensing or con-  
trolling circuit boards. Instead, the generator control  
console houses a “Printed Circuit Board Assembly”,  
which controls all phases of operation, including  
engine start up and load transfer.  
Temperature  
Above 80° F (27° C)  
32° to 80° F (-1° to 27° C)  
Below 32° F (0° C)  
Oil Grade (Recommended)  
SAE 5W-20  
2.1 STANDBY GENERATOR  
INSTALLATION  
SAE 5W-20  
SAE 5W-20  
DANGER  
NOTE:  
Connecting this generator to an electrical sys-  
tem normally supplied by an electric utility  
shall be by means of a transfer switch, so as to  
isolate the electric system from the utility distri-  
bution 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.  
Synthetic oil is highly recommended in any element  
with temperatures above 90° F or below 30° F.  
Any attempt to crank or start the engine before  
it has been properly serviced with the recom-  
!
mended oil may result in an engine failure.  
If an open bottom is used, the engine-genera-  
tor is to be installed over non-combustible  
materials and should be located such that com-  
bustible materials are not capable of accumu-  
lating under the generator set.  
1.15 COOLANT RECOMMENDATIONS  
Use a mixture of half low silicate ethylene glycol base  
anti-freeze and half de-ionized water. Cooling system  
capacity is about 12 U.S. quarts (11.4 liters). Use only  
de-ionized water and only low silicate anti-freeze. If  
desired, add a high quality rust inhibitor to the rec-  
ommended coolant mixture. When adding coolant,  
always add the recommended 50-50 mixture.  
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 regula-  
tions pertaining to the installation.  
Do not use any chromate base rust inhibitor  
with ethylene glycol base anti-freeze or chromi-  
!
umhydroxide (“green slime”) forms and will  
cause overheating. Engines that have been  
operated with a chromate base rust inhibitor  
must be chemically cleaned before adding eth-  
ylene glycol base anti-freeze. Using any high  
silicate anti-freeze boosters or additives will  
also cause overheating. It is also recommend  
that any soluble oil inhibitor is NOT USED for  
this equipment.  
After the system has been installed, do nothing  
that might render the installation in noncompli-  
ance with such codes, standards and regula-  
tions.  
!
2.1.1 NFPA STANDARDS  
The following published standards booklets pertain-  
ing to standby electric systems are available form the  
National Fire Protection Association (NFPA),  
Batterymarch Park, Quincy, MA 02269:  
1.16 BEFORE INSTALLATION  
Before installing this equipment, check the ratings of  
both the generator and the transfer switch. Read  
“Emergency Isolation Method” and “Total Circuit  
Isolation Method” in Sections 2.6 and 2.6.  
NOTE:  
It is essential to use the latest version of any stan-  
dard to ensure correct and current information.  
®
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Section 2 — Installation  
Guardian Liquid-cooled 27 kW and 30 kW Generators  
• NFPA No. 37, STATIONARY COMBUSTION  
• Where strong prevailing winds blow from one  
direction, face the generator air inlet openings into  
the prevailing winds.  
• Install the generator as close as possible to the  
transfer switch. This reduces the length of wiring  
and conduit.  
ENGINES AND GAS TURBINES.  
• NFPA No. 76A, ESSENTIAL ELECTRICAL SYS-  
TEMS FOR HEALTH CARE FACILITIES.  
• NFPA No. 220, STANDARD TYPES OF BUILDING  
CONSTRUCTION  
• Install the generator as close as possible to the fuel  
supply, to reduce the length of piping. HOWEVER,  
REMEMBER THAT LAWS OR CODES MAY REG-  
ULATE THE DISTANCE.  
• NFPA No. 68, GUIDE FOR EXPLOSION VENTING  
• NFPA No. 70, NATIONAL ELECTRICAL CODE.  
• NFPA No. 30, FLAMMABLE AND COMBUSTIBLE  
LIQUIDS CODE.  
• NFPA No. 10, INSTALLATION, MAINTENANCE AND  
2.3 GENERATOR MOUNTING AND  
USE OF PORTABLE FIRE EXTINGUISHERS.  
SUPPORT  
2.1.2 OTHER PUBLISHED STANDARDS  
Retain the generator compartment to a concrete slab  
with 1/4-inch masonry type anchor bolts. Be sure the  
bolts are long enough to retain the compartment. The  
slab should be at least six inches thick and should  
extend beyond the enclosure to a distance of at least  
three inches on all sides. See Section 6 for generator  
major dimensions.  
In addition to NFPA standards, the following infor-  
mation pertaining to the installation and use of  
standby electric systems is available:  
NOTE:  
It is essential to use the latest version of any stan-  
dard to ensure correct and current information.  
2.4 BASIC STANDBY ELECTRIC  
• 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.  
SYSTEM  
Figure 2.1 shows a schematic diagram of a basic  
standby electric system. Both the UTILITY power  
supply and the STANDBY (GENERATOR) output are  
connected to an approved transfer switch. The trans-  
fer switch is required by electrical code and serves  
the following functions:  
• Allows the LOAD circuits to be connected to only  
one power supply at a time.  
• Prevents electrical backfeed between the generator  
and the UTILITY power circuits.  
Notice that both the STANDBY and the UTILITY  
power supplies to the transfer switch are protected  
against overload by a main line circuit breaker.  
2.2 GENERATOR LOCATION  
Figure 2.1 – Basic Standby Electric System  
Install the generator set, in its protective enclosure  
outdoors, where adequate cooling and ventilating air  
always is available. Consider these factors:  
• Install the unit where air inlet and outlet openings  
will not become obstructed by leaves, grass, snow,  
etc. If prevailing winds will cause blowing or 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.  
• This genset must be installed on a level surface.  
The base frame must be level within 1/2 inch all  
around.  
• Allow sufficient room on all sides of the generator  
for maintenance and servicing. A good rule is to  
allow five feet of space on all sides.  
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Section 2 — Installation  
Guardian Liquid-cooled 27 kW and 30 kW Generators  
Figure 2.2 – Generator Grounding Lug (typical)  
2.5 EMERGENCY CIRCUIT ISOLATION  
METHOD  
This prevents overloading the generator by keeping  
electrical loads below the wattage/amperage capacity  
of the generator. If the generator is powering only crit-  
ical loads, within the wattage/amperage capacity, dur-  
ing utility power outages, consider using the emer-  
gency circuit isolation method.  
GROUNDING  
LUG  
Critical electrical loads are grouped together and  
wired into a separate “Emergency Distribution  
Panel.” Load circuits powered by that panel are with-  
in the wattage/amperage capacity of the generator set.  
When this method is used, it is difficult to overload  
the generator. The transfer switch must meet the fol-  
lowing requirements:  
DANGER  
Do not connect the ground wire to any pipe  
that carries a flammable or explosive substance  
– FIRE or an EXPLOSION may result.  
• It must have an ampere rating equal to the total  
amperage rating of the emergency distribution  
panel circuit.  
• Have it installed between the building’s main dis-  
tribution panel and the emergency distribution  
panel.  
Proper grounding helps protect personnel against  
electrical shock in the event of a ground fault condi-  
tion in the generator or in connected electrical  
devices. In addition, grounding helps dissipate static  
electricity that often builds up in ungrounded  
devices.  
2.6 TOTAL CIRCUIT ISOLATION  
METHOD  
When a generator capable of powering all electrical  
loads in the circuit is to be installed, use the “Total  
Circuit Isolation Method.” It is possible for the gener-  
ator to be overloaded when this isolation method is  
employed. The following apply to the transfer switch  
in this type of system.  
2.8 GENERATOR AC NEUTRAL  
CONNECTIONS  
Generac uses an UNGROUNDED AC neutral.  
Grounding is recommended only at the main service  
entrance. If the neutral wire is grounded and one of  
the phase loads becomes grounded, the excessive  
current opens the load circuit breaker or collapses  
the generator field. The actual result depends on the  
electrical characteristics of the particular installed  
generator.  
• Ampere rating of the transfer switch must equal  
the ampere rating of the normal incoming utility  
service.  
• The transfer switch is installed between the utility  
service entrance and the building distribution  
panel.  
2.7 GROUNDING THE GENERATOR  
The National Electrical Code requires the frame and  
external electrically conductive parts of this equip-  
ment to be properly connected to an approved earth  
ground and/or grounding rods. For that purpose, a  
GROUND LUG (Figure 2.2) is provided on the gener-  
ator mounting base. Consult a qualified electrician  
for grounding requirements in the area. Grounding  
procedures must meet local regulations.  
Failure to connect the generator neutral prop-  
!
erly will result in unbalanced line-to-neutral  
voltages. Resulting high voltages will cause  
equipment damage.  
2.9 TRANSFER SWITCH SIGNAL  
CONNECTIONS  
2.9.1 PRE-PACKAGED ATS  
If the generator is to be installed with a pre-packaged  
transfer switch, it is necessary to connect the control  
wires to the generator and set position two of the  
four-position dip switch to OFF.  
Setting switch two to OFF allows the control PCB to  
perform the ATS control functions.  
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Section 2 — Installation  
Guardian Liquid-cooled 27 kW and 30 kW Generators  
Control system interconnections consist of N1 and  
Spilled electrolyte is to be washed down with  
!
N2, and leads 23 and 194. Control system intercon-  
nection leads must be run in a conduit that is sepa-  
rate from the AC power lead. Recommended wire  
gauge sizes for this wiring depends on the length of  
the wire, as recommended below:  
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.  
MAXIMUM WIRE LENGTH  
RECOMMENDED WIRE  
SIZE  
460 feet (140m)  
No. 18 AWG.  
No. 16 AWG.  
No. 14 AWG.  
No. 12 AWG.  
461 to 730 feet (223m)  
731 to 1,160 feet (354m)  
1,161 to 1,850 feet (565m)  
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.  
!
2.9.2 GTS-TYPE ATS  
If the generator is to be installed with an automatic  
transfer switch, such as an engineered Generac GTS-  
type switch, it is necessary to connect the two-wire  
start control system.  
The battery represents a risk of high short cir-  
cuit current. When working on the battery,  
always remove watches, rings or other metal  
objects, and only use tools that have insulated  
handles.  
Connect the two-wire start signal from the automatic  
transfer switch to the automatic start connection,  
which is located in the middle, on the bottom, inside  
the control panel. Match wires 178 and 183 in the  
transfer switch to 178 and 183 on the terminal strip  
in the control panel. The conductors for the two-wire  
start circuit must be in their own conduit. (See  
Section 3.1 for further explanation.)  
When replacing batteries, use the same number and  
type of battery. The recommended batteries are  
Group 26, 12V negative ground 525 CCA/75 AH min-  
imum capacity, or Group 27F, 12V negative ground  
600 CCA/90 AH minimum capacity. All batteries  
must be at 100 percent state-of-charge before they  
are installed on the generator.  
2.10 BATTERY INSTALLATION  
When using maintenance-free batteries, it is not nec-  
essary to check the specific gravity or electrolyte level.  
Have these procedures performed at the intervals  
specified in Section 4, “Maintenance.” A negative  
ground system is used. Battery connections are  
shown on the wiring diagrams. Make sure all batter-  
ies are correctly connected and terminals are tight.  
Observe battery polarity when connecting batteries to  
the generator set.  
DANGER  
Standby generators installed with automatic  
!
transfer switches will crank and start automati-  
cally when NORMAL (UTILITY) source voltage is  
removed or is below an acceptable preset level.  
To prevent such automatic start-up and possible  
injury to personnel, do not connect battery  
cables until certain that normal source voltage  
at the transfer switch is correct and the system  
is ready to be placed into operation.  
NOTE:  
Damage will result if the battery connections are  
made in reverse.  
Storage batteries give off explosive hydrogen  
gas. This gas can form an explosive mixture  
around the battery for several hours after  
charging. The slightest spark can ignite the gas  
and cause an explosion. Such an explosion can  
shatter the battery and cause blindness or  
other injury. Any area that houses a storage  
battery must be properly ventilated. Do not  
allow smoking, open flame, sparks or any spark  
producing tools or equipment near the battery.  
2.11 PREPARATION BEFORE START-UP  
The instructions in this section assume that the  
standby generator has been properly installed, serv-  
iced, tested, adjusted and otherwise prepared for use  
by a competent, qualified installation contractor. Be  
sure to read the “Safety Rules” on Pages 2 and 3, as  
well as all other safety information in this manual,  
before attempting to operate this (and related) equip-  
ment.  
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.  
!
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Section 3 — Operation  
Guardian Liquid-cooled 27 kW and 30 kW Generators  
2.11.1 PRIOR TO INITIAL START-UP  
2.11.6 BELT TENSION  
Check the engine fan belt tension and condition prior  
to placing the unit into service and at recommended  
intervals. Belt tension is correct when a force of  
approximately 22 pounds (10 kg), applied midway  
between pulleys, deflects the belt about 3/8- to 5/8-  
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 quantities of engine fluids (oil, coolant,  
fuel, etc.) may result in an engine failure.  
!
2.11.7 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  
intervals, 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,  
properly installed and interconnected, and ready for  
use.  
2.11.2 TRANSFER SWITCH  
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.  
If this generator is used to supply power to any elec-  
trical system normally powered by an electric utilit