Generac Power Systems 00919-0 User manual

THIS SYMBOL POINTS OUT IMPORTANT SAFETY INSTRUCTIONS, WHICH, IF NOT FOLLOWED, COULD ENDANGER THE
PERSONAL SAFETY AND/OR PROPERTY OF YOURSELF AND OTHERS. READ AND FOLLOW ALL INSTRUCTIONS IN THE
MANUAL BEFORE ATTEMPTING TO OPERATE THIS UNIT.
Model No. 00919-0 Series NP-50LPG
GENERAC®
CORPORATION
OWNER’S MANUAL
Manual No. A5596
General
General
Inf
Information ormation
Revision 1 (6/1/98) Printed in U.S.A.
GENERAC®
Air-cooled Recreational
Vehicle Generator

Study these SAFETY RULES carefully before installing, operating or ser-
vicing this equipment. Become familiar with the Owner’s Manual and with
thegenerator. Thegeneratorcanoperatesafely, efficiently and reliablyonly
if it is properly installed, operated and maintained. Many accidents are
caused by failing to follow simple and fundamental rules or precautions.
Generaccannotpossiblyanticipateevery possiblecircumstancethatmight
involveahazard.ThewarningsinthisManualandontagsanddecalsaffixed
totheunit,aretherefore, not all-inclusive.Ifyou use a procedure,workmethod
or operating technique Generac does not specifically recommend, you
must satisfy yourself that it is safe for you and others. You must also make
sure the procedure, work method or operating technique that you choose
does not render the generator to be unsafe.
• For fire safety, the auxiliary generator must be installed and maintained
properly. Installation must always comply with applicablecodes,standards,
laws and regulations. Adhere strictly to local, state and national electri-
calandbuildingcodes. Comply with regulations the Occupational Safety
and Health Administration (OSHA) established. Also, the generator and
related components must be installed completely in conformance with
themanufacturer’s instructionsandrecommendations.Followingproper
installation, do nothing that might alter a safe installation and render the
unitinnon-compliancewithsuchcodes,standards,laws and regulations.
The Recreational Vehicle Generator produces extremely high and
dangerous electrical voltages and can cause dangerous, and possi-
blyfatal, electrical shock.Avoidcontactwithbarewires,terminals,etc.
while the unit is running. If you must work around an operating gen-
erator, stand on an insulated, dry surface to reduce shock hazard.
Never work on this equipment or handle any electrical device while
standing in water, while barefoot, or while hands or feet are wet. Dan-
gerous electrical shock will result.
• Have the generator properly grounded (bonded) during installation onto
the vehicle, either by solid mounting to the vehicle frame or chassis or
by means of an approved bonding conductor. DO NOT disconnect the
bonding conductor, if so equipped. DO NOT reconnect the bonding con-
ductortoanygeneratorpart that might be removedordisassembled during
routine maintenance. If the grounding conductor must be replaced, use
only a flexible conductor that is of No. 8 AWG copper wire minimum.
• Keep hands, feet, clothing, etc., away from drive belts, fans and other
moving parts of this equipment. Never remove any drive belt or fan
guards while the unit is operating.
• Inspect the generator periodically. Repair or replace all damaged or
defective parts immediately.
In case of accident caused by electric shock, shut down the source
ofelectrical poweratonce.Ifthiscannotbedone,freevictimfromlive
conductor. AVOID DIRECT CONTACT WITH THE VICTIM. Use a dry
board, dry rope, or other non-conducting implement to free the victim
from live conductor. If victim is unconscious, apply first aid and get
medical help
• Inspect fuel system frequently for leaks or damage. Repair or replace
any damaged or leaking component immediately. Never attempt to
change, alter or modify the generator fuel system in any way that might
affect safety or compliance with applicable codes and standards.
Thegeneratorenginegives off DEADLYcarbonmonoxide gas through
its exhaust system. This dangerous gas, if breathed in sufficient con-
centrations, can cause unconsciousness or even death. This exhaust
system must have been properly installed, in strict compliance with
applicable codes and standards. Following installation, you must do
nothingthatmightrenderthesystemunsafe or in non-compliance with
suchcodesandstandards.Thegeneratorcompartment must be com-
pletelyvaporsealedfromvehicle interior.Theremust be no possibility
of exhaust fumes entering the vehicle interior. Never operate this
equipment with a leaking or defective exhaust system.
• 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.
• Do not smoke around the generator. Wipe up any fuel or oil spills imme-
diately.Neverleave oily or fuel soakedragsinthegeneratorcompartment
or on the generator itself. Keep the area around the generator clean and
free of debris.
• Adequateventilationisrequiredtoexpeltoxic fumes and fuel vaporsfrom
the generator compartment. Do not alter the installation of this equip-
mentinanymannerthatmightobstructairandventilationopenings. Such
openings must be kept clear and unobstructed.
Somegeneratorsmay use LP gas (propane) as a fuel. LP gas is highly
EXPLOSIVE. The gas is heavier than air and tends to settle in low
areas where even the slightest spark can ignite the gas and cause an
explosion.
• Before performing any maintenance on the generator set, 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.
2
Recreational Vehicle Generator
Generac NP-50LPG Recreational Vehicle Generator
THE MANUFACTURER SUGGESTS THAT THESE “RULES” FOR SAFE OPERATION BE COPIED AND POSTED IN
POTENTIAL HAZARD AREAS OF THE RECREATIONAL VEHICLE. SAFETY SHOULD BE STRESSED TO ALL
OPERATORS AND POTENTIAL OPERATORS OF THIS EQUIPMENT.
The engine exhaust from this product
contains chemicals known to the State
of California to cause cancer, birth
defects, or other reproductive harm.
WWAARRNNIINNGG::
GENERAC®
CORPORATION

3
Recreational Vehicle Generator
Generac NP-50LPG Recreational Vehicle Generator
IDENTIFI-
CATION
RECORD
Please record the following information from the generator DATA DECAL or information decal.
1. Model Number_______________________ 2. Serial Number_________________
3. kW Rating___________________________ 4. Rated Voltage__________________
REFERENCE NUMBER IDENTIFICATION
1. Generator Air Intake Screen
2. Data Decal
3. Oil Dipstick
4. Oil Filler Cap
5. Oil Drain Plug
6. Oil Filter
7. Fuel Regulator
8. Fuel Solenoid
9. Fuel Inlet
10. Fuel Primer Switch
11. Circuit Breakers
12. Fuse
13. Engine Start/Stop Switch
14. Air Cleaner
15. Optional Remote Panel Receptacle
16. Generator AC Output Leads
17. Starter Contactor
1
2
3
4
5678
9
10
11
13
14
15
16
GENERAC®
CORPORATION
12
SIDE VIEW
17

4
Recreational Vehicle Generator
Generac NP-50LPG Recreational Vehicle Generator
TABLE
OF
CONTENTS
SAFETY RULES................................................................2
IDENTIFICATION RECORD..............................................3
GENERAL FEATURES ....................................................3
READ THIS MANUAL THOROUGHLY ............................5
Operation and Maintenance........................................................5
How to Obtain Service ................................................................5
GENERATOR FAMILIARIZATION ....................................6
Generator Applicability................................................................6
Installation ..................................................................................6
Safety..........................................................................................6
Generator AC Connection System..............................................6
OPERATION ................................................................7-11
Generator Control Panel ............................................................7
Optional Remote Start/Stop Panel..............................................7
Before Starting the Engine..........................................................8
Starting the Generator ............................................................8-9
Stopping the Generator ..............................................................9
Applying Loads to Generator ................................................9-10
Additional Information..........................................................10-11
SPECIFICATIONS ..........................................................12
Fuel Requirements....................................................................12
Engine Oil Requirements..........................................................12
Engine Specifications................................................................12
Generator Specifications ..........................................................12
MAINTENANCE ........................................................13-16
Checking Engine Oil Level........................................................13
Change Engine Oil....................................................................13
Change Oil Filter ......................................................................13
Engine Air Cleaner....................................................................14
Clean Air Intake Screen............................................................14
Engine Spark Plug ....................................................................14
Spark Arrestor Muffler ..............................................................15
Cleaning the Generator ............................................................15
Battery ......................................................................................15
Major Service Manual ..............................................................16
Drive Belts ................................................................................16
Exercising the Generator ..........................................................16
Out of Service Protection..........................................................16
Return the Unit to Service after Storage ..................................16
TROUBLESHOOTING ....................................................17
REPAIR PARTS..........................................................20-29
ELECTRICAL DATA ..................................................18-19
EMISSIONS WARRANTY ..........................................30-31
BASIC 3-YEAR WARRANTY ...........................back cover
GENERAC®
CORPORATION

5
Recreational Vehicle Generator
READ THIS MANUAL THOROUGHLY
Ifyoudon't understand any portion of this manual,contactGen-
erac for a demonstration of actual starting, operating and
servicing procedures.
Throughout this publication and on tags and decals affixed to
thegenerator,DANGERandCAUTIONblocksareusedtoalert
youto special instructionsaboutaparticularoperationthatmay
be hazardous if performed incorrectly or carelessly. Observe
them carefully.
Thesesafety warningscannoteliminatethehazardsthatthey
indicate. Strict compliance with the special instructions while
performing the service plus “common sense” are major mea-
sures to prevent accidents.
ThefollowingdefinitionsapplytoDANGER, WARNING,CAU-
TION and NOTE blocks found throughout the manual.
DANGER: AFTER THIS HEADING YOU CAN READ
HANDLING, INSTALLING, OPERATING OR SERVIC-
ING INSTRUCTIONS THAT, IF NOT COMPLIED
WITH, WILL RESULT IN PERSONAL INJURY.
WARNING: AFTER THIS HEADING YOU CAN READ
HANDLING, INSTALLING, OPERATING OR SERVIC-
ING INSTRUCTIONS THAT, IF NOT COMPLIED
WITH, MAY RESULT IN PERSONAL INJURY.
CAUTION: After this heading you can read instruc-
tions for handling, installing, operating or
servicing the generator that, if not strictly com-
plied with, may result in damage to equipment
and/or property.
NOTE: After this heading youcanreadexplanatorystatements
that require special emphasis.
These symbols indicate the following:
The operator (owner) is responsible for proper and safe use
of the vehicle, equipment on the vehicle, and the safety of all
vehicle occupants. We strongly recommend that the opera-
tor read this Owner’s Manual and thoroughly understand all
instructions beforeusingthisequipment. Wealsostronglyrec-
ommendinstructing other occupants in the vehicletoproperly
start and operate the generator. This prepares them if they
need to operate the equipment in an emergency.
OPERATION AND MAINTENANCE
It is the operator's responsibility to perform all safety checks;
to make sure that all maintenance for safe operation is per-
formed promptly; and to have the equipment checked by an
Authorized Dealer periodically. Normal maintenance service
and replacement of parts are the responsibility of the
Owner/Operator and, as such, are not considered defects in
materials or workmanship within the terms of the warranty. Indi-
vidual operating habits and usage contribute to the need for
maintenance service.
Proper maintenance and care of your recreational vehicle
generatorassuresaminimumnumber of problemsandkeeps
your operating expenses at a minimum. See your authorized
Dealer/Distributor for service aids and accessories.
HOW TO OBTAIN SERVICE
Whenyourrecreational vehiclegeneratorsetrequiresservicing
or repairs, simply contact an Authorized Service Facility for
assistance. Service technicians are factory-trained and are
capable of handling all of your service needs.
When contacting an Authorized Service Facility or the factory
about parts and service, always supply the complete model
number and serial number of your unit as given on its data
decal.
The warranty on your generator is included in the Owner’s
Manual, as well as listings for repair parts.
Generac NP-50LPG Recreational Vehicle Generator
RREEAADD
TTHHIISS
MMAANNUUAALL
Points out important safety information and, if not fol-
lowed, could endanger personal safety and/or property
of yourself and others.
Potential explosion hazard.
Potential fire hazard.
Potential electrical shock hazard.
GENERAC®
CORPORATION
SERVICE DEALER LOCATION
TO LOCATE THE NEAREST GENERAC SERVIC-
ING DEALER, PLEASE CALL OUR 800 NUMBER.
ONLY DEALER LOCATION INFORMATION CAN BE
OBTAINED AT THIS NUMBER.
1-800-333-1322

6
Recreational Vehicle Generator
Generac NP-50LPG Recreational Vehicle Generator
GENERATOR APPLICABILITY
These generators have been designed and manufactured for
supplyingelectrical powerfor recreational vehicles. You should
notmodifythegeneratororuseitfor anyapplicationotherthan
for what it was designed. If there are any questions pertain-
ing to its application, write or call the factory. Do not use the
unit until you have been advised by a competent authority.
DANGER: FOR FIRE SAFETY, THE GENERATOR
MUST HAVE BEEN PROPERLY INSTALLED IN
COMPLIANCE WITH (1) ANSI 119.2-1975/NFPA
501C-1974 “STANDARD FOR RECREATIONAL
VEHICLES, PART III, “INSTALLATION OF ELECTRI-
CAL SYSTEMS.” THE GENERATOR ALSO MUST
HAVE BEEN INSTALLED IN STRICT COMPLIANCE
WITH THE MANUFACTURER’S DETAILED INSTAL-
LATION INSTRUCTIONS. AFTER INSTALLATION,
DO NOTHING THAT MIGHT RENDER THE UNIT IN
NON-COMPLIANCE WITH SUCH CODES, STAN-
DARDS AND INSTRUCTIONS.
Youcanusethisgeneratortosupplyelectricalpowerforoper-
ating 120/240 volts, single phase, 60 Hertz, AC electrical
loads. These loads can require up to 4500 watts of (4.5kW)
of power, but cannot exceed 37.5 AC amperes of current at
120 volts or exceed 18.8 AC amperes at 240 volts.
CAUTION: Do not overload the generator. Some
installations may require that electrical loads be
alternated to avoid overloading. Applying exces-
sively high electrical loads may damage the
generator and may shorten its life. Add up the
rated watts of all electrical lighting, appliance, tool
and motor loads the generator will power at one
time. This total should not be greater than the
wattage capacity of the generator. If an electrical
device nameplate gives only volts and amps, multi-
ply volts times amps to obtain watts (volts x amps
= watts). Some electric motors require more watts
of power (or amps of current) for starting than for
continuous operation.
INSTALLATION
This Owner’s Manual has been prepared under the assump-
tion that a competent, qualified technician installed the
generator. We also assume the installer complied with all
applicable codes, standards and regulations pertaining to
installation.
Owners/Operators must make sure to do nothing that might
rendertheinstallationunsafe or in noncompliance with applic-
able codes, standards and instructions. They should be sure
theunithasbeeninstalledtoallowadequateventilation forcool-
ing and exhaust air.
SAFETY
Before attempting to use the generator set, carefully read
GENERAL SAFETY RULES inside the cover of this Manual.
Comply strictly with these RULES to prevent accidents and
damagetoequipmentand/orproperty. Wesuggest that copy-
ingandpostingGENERALSAFETYRULES in potential hazard
areas of the vehicle. Stress safety to all operators and poten-
tial operators of this equipment.
GENERATOR AC CONNECTION
SYSTEM
This generator set is equipped with dual stator AC power
windings. These two stator windings supply electrical power
to customer electrical loads by means of a dual 2-wire con-
nection system. Note, however, that neutral is grounded.
Thegeneratormay have been installed so that the unit powers
120 volt AC loads (Figure 1); or you can wire them to connect
both120and/or240volt ACelectrical loads. Besuretoinstall
jumper wire between the circuit breakers when reconnecting
for 120/240 volts. Refer to the Installation Manual for more
information.
Figure 1 — Connections for 120 Volts Only
GENERAL
INFORMA-
TION
GENERAC®
CORPORATION

7
Recreational Vehicle Generator
Generac NP-50LPG Recreational Vehicle Generator
GENERATOR CONTROL PANEL
Mounted on the generator control panel (Figure 2) are the fol-
lowing features:
Figure 2 — Generator Control Panel
FUEL PRIMER
Before starting a cold engine (if it has not been started in more
than two weeks), you must press this switch to bring fuel from
the tank to the fuel regulator. This rocker type switch springs
back into its original position when you release it.
START/STOP SWITCH
To crank and start the engine, hold this switch at its START
position. Release the switch when the engine starts. To stop
an operating engine, press and hold the switch in its STOP
position until the engine shuts off. The switch center position
is the RUN position.
FUSE
Protects the engine DC control circuit against electrical over-
load. Ifthefuseelementhasmeltedopenduetooverloading,
theenginecannotbecranked. If youmustreplaceit,useonly
an identical replacement fuse.
MAIN BREAKER
ProtectsgeneratorsAC output circuit against overloadandpro-
vides a method of turning OFF the generators 120/240 volts
AC output to vehiclecircuits. TheNP-50LPG has one 20 amp
breaker and one 30 amp breaker.
NOTE: If the Series NP-50LPG has been reconnected fordual
voltage AC output (120/240 volts), you can install line break-
ers having an amperage rating that is different than stated
above. The replacement line breakers consist of two sepa-
rate breakers with a connecting piece between the breaker
handles (so that both breakers will operate at the same time).
If the unit is reconnected for dual voltage, IT IS NO LONGER
RVIA LISTED.
OPTIONAL REMOTE
START/STOP PANEL
AremotemountedStart/StopPanel is available, which allows
you to start and stop the generator engine conveniently from
inside the vehicle.
Figure 3 — Optional Remote Panel (Model 9042)
GENERAC®
CORPORATION

8
Recreational Vehicle Generator
BEFORE STARTING THE ENGINE
IMPORTANT: INSTRUCTIONSANDINFORMATION IN THIS
MANUAL ASSUME THE GENERATOR HAS BEEN PROP-
ERLYINSTALLED,CONNECTED, SERVICED, TESTED AND
ADJUSTEDBYAQUALIFIEDINSTALLATION TECHNICIAN
OR INSTALLATION CONTRACTOR.
INSTALLATION
Generator installation must have been properly completed so
it complies with all applicable codes, standards and regula-
tions and with the manufacturer's recommendations.
ENGINE LUBRICATION
Haveenginecrankcaseproperly servicedwithrecommended
oil before starting. Refer to MAINTENANCE and SPECIFI-
CATIONS sections for oil servicing procedures and
recommendations.
CAUTION: Any attempt to crank or start the engine
before you have properly serviced it with the recom-
mended oil may result in an engine failure.
FUEL SUPPLY
Theenginemusthaveadequatesupplyofproperfueltooper-
ate. Before starting, check that sufficient fuel is available.
COOLING AND VENTILATING AIR
Air inlet and outlet openings in generator compartment must
be open and unobstructed for continued proper operation.
Without sufficient cooling and ventilating air flow, the engine-
generator quickly overheats which causes it to shutdown and
it could damage the generator.
ENGINE EXHAUST GAS
Before starting the generator engine,you should be sure there
is no way for exhaust gases to enter the vehicle interior and
endangerpeopleoranimals. Closewindows, doors and other
openingsinthevehicle that, if open, might permit exhaust gases
to enter the vehicle.
DANGER: The generator engine gives off DEADLY
carbon monoxide gas through its exhaust system.
This dangerous gas, if breathed in sufficient con-
centrations, can cause unconsciousness or even
death. DO NOT OPERATE THE GENERATOR IF
THE EXHAUST SYSTEM IS LEAKING OR HAS
BEEN DAMAGED. SYMPTOMS OF CARBON
MONOXIDE POISONING ARE (a) inability to think
coherently; (b) vomiting; (c) twitching muscles; (d)
throbbing temples; (e) dizziness; (f) headaches;
(g) weakness and sleepiness. IF YOU FEEL ANY
OF THESE SYMPTOMS, MOVE INTO FRESH AIR
IMMEDIATELY. IF SYMPTOMS PERSIST, GET MED-
ICAL HELP.
STARTING THE GENERATOR
IMPORTANT: Read the vehicle manufacturer’s instructions.
The owner/operator should become familiar with the vehicle
in which the generator is installed. Differences exist between
vehicles. For example, some vehicles may use a transfer
switch to isolate docksidepower from the generator, while other
vehicles may use an isolating receptacle. Some vehicles may
be equipped with a DC converter which allows the generator
to power certain DC lighting and other DC loads.
To start the generator from either the generator control panel
or from the optional Remote Panel, proceed as follows:
1.Turn OFF electrical loads, using whatever means provided
in your vehicle (such as a main line circuit breaker or trans-
fer switch).
NOTE: If starting from the generator panel, turn OFF loads
by setting the generator’s main circuit breaker to “OFF” or
“OPEN”. IfstartingfromaRemotePanel, turnOFFloadsusing
whatevermeansisprovidedin the vehicle(suchasamaincir-
cuit breaker). Electrical load circuits will be turned ON after
the generator has started, stabilized and warmed up.
2. Ifyouhavenot started the engine in more than twoweeks,
press the Fuel Primer switch and hold it for about 30 seconds
toprime fuel system. However, if the engine is warm,skipStep
2.
Generac NP-50LPG Recreational Vehicle Generator
GENERAC®
CORPORATION

9
Recreational Vehicle Generator
3.HoldtheengineStart/StopSwitchatSTART to crank engine.
Release the switch when the engine starts.
CAUTION: If the engine does not start after it has
been cranking for 15 seconds, release the
start/stop switch and try again. Holding the switch
for longer than 15 seconds can damage the starter
motor.
4.Let the engine run at no-load for a few minutes to stabilize
and warm up.
5.Turn ON electrical loads, using whatever means provided
(such as a main circuit breaker or transfer switch).
STOPPING THE GENERATOR
1.Turn OFF all electrical loads, using whatever means pro-
vided (such as a main circuit breaker or transfer switch).
2.Let unit run a few minutes to stabilize temperature.
3.Hold the Start/Stop switch in its STOP position until engine
comes to a complete stop.
APPLYING LOADS TO GENERATOR
Whenapplyingelectrical loads to the generator,observe these
guidelines:
Before applying electrical loads, let the generator stabilize
and warm up for a minute or two.
DO NOT overload the generator.
LET ENGINE STABILIZE
The generator supplies correct rated voltage only at proper
governed speed. Some electrical appliances may be extremely
sensitive to voltage. Incorrect voltages can damage those
appliances.
If electrical loads are applied at reduced operating speeds,
such loads imposed on the engine when sufficient power is not
available may shorten engine life. Never turn ON electrical
loads until after the generator engine has started and stabi-
lized ON-speed.
DO NOT OVERLOAD THE GENERATOR
Youcanreadtheratedwattage/amperage capacity of yourgen-
eratoronthegeneratordata decal (see “Identification Record”
on Page 3).
Applying electrical loads in excess of the unit’s rated capac-
itywillcausetheengine-generatortoautomaticallyshutdown.
To avoidoverloading, addupthewattageofallconnected elec-
trical lighting,appliance,toolandmotor loads. Thistotalshould
not be greater than the generator’s rated wattage capacity.
Mostlighting,appliance,tool,andmotorloadsindicatetheir
required watts on their nameplate or data plate. For light
bulbs, simply note the wattage rating of the bulb.
Ifaloaddoesnotshowitsratedwattage,multiplythat load’s
rated VOLTS times AMPS to obtain WATTS.
Generac NP-50LPG Recreational Vehicle Generator
RUNNING
WATTS
*Air Conditioner (12,000 Btu)..........................................1700
Battery Charger (20 amp) ................................................500
Belt Sander (3”) ..............................................................1000
Chain Saw ......................................................................1200
Circular Saw (6-12”) ............................................800 to 1000
Coffee Maker ..................................................................1000
*Compressor (1HP) ........................................................2000
*Deep Freeze....................................................................500
Disc Sander (9”)..............................................................1200
Electric Range (one element) ........................................1500
Electric Skillet..................................................................1250
*Furnace Fan (1/3 HP)....................................................1200
Hair Dryer........................................................................1200
Hand Drill (1”)..................................................................1100
Hedge Trimmer ................................................................450
Impact Wrench..................................................................500
RUNNING
WATTS
Lawn Mower....................................................................1200
Light Bulb..........................................................................100
Microwave Oven................................................................700
*Milk Cooler ....................................................................1100
Oil Burner on Furnace ......................................................300
Oil Fired Space Heater (140,000 Btu) ..............................400
*Paint Sprayer, Airless (1/3 HP)........................................600
Radio........................................................................50 to 200
*Refrigerator......................................................................600
Slow Cooker......................................................................200
*Submersible Pump (1-1/2 HP) ......................................2800
*Submersible Pump (1 HP) ............................................2000
*Table Saw (10”) ................................................1750 to 2000
Television ..........................................................1750 to 2000
* Allow 2-1/2 times the listed watts for starting these devices.
WATTAGE REFERENCE GUIDE
GENERAC®
CORPORATION

10
Recreational Vehicle Generator
Induction type motors (such as those that run the vehicle’s
furnacefan,refrigerator,airconditioner,etc.)needabout2-
1/2 time more watts of power for starting than for running
(for a few seconds during motor starting). Be sure to allow
for this when connecting electrical loads to the generator.
First, figure the watts needed to start electric motors in the
system. To that figure, add the running wattages of other
items that will be operated by the generator.
Do not apply heavy electrical loads for the first two or three
hours of operation.
ADDITIONAL INFORMATION
Thissectiondiscussessomethetheengineprotective devices,
overload protection and breaking in a new generator.
AUTOMATIC LOW OIL PRESSURE
SHUTDOWN
Theengineisequippedwithanormally-closed(N.C.)oilpres-
sure switch (Figure 4). Engine oil pressure holds the switch
openduring cranking and operation. Shouldoilpressuredrop
belowapre-setlevel,the switchcontactscloseandtheengine
automatically shuts down.
HIGH TEMPERATURE SHUTDOWN
Atemperatureswitch (Figure 4) with normally-open(N.O.)con-
tacts is mounted near the oil filter. If engine temperature were
to exceed about 284°F (140°C), the switch contacts close
and the engine shuts down.
Figure 4 — Switches for Engine
Safety Shutdown
FIELD BOOST
The Controller Circuit Board houses a field boost diode and
resistor which are part of a “field boost” circuit (Figure 5).
During engine cranking only, a positive DC (battery) voltage
isdelivered through the diode, resistor,brushes and slip rings,
and the generator rotor. Application of this voltage to the
rotor “flashes the field” whenever it is started. Flashing of the
field each time the generator starts makes sure that a suffi-
ciently strong magnetic field is available to produce “pick-up”
voltage in the stator windings.
Figure 5 — Field Boost Circuit
OVERVOLTAGE PROTECTION
A solid state voltage regulator (Figure 6) controls the gener-
ator’sAC output voltage. This regulator supplies an excitation
current to the rotor. By regulating the rotor’s excitation cur-
rent, the strength of its magnetic field is regulated and, in
turn, the voltage delivered to connected electrical loads is
controlled. When the AC frequency is 60 Hz, voltage is reg-
ulated at 120 volts (voltage-to-frequency ratio is 2-to-1).
Figure 6 — Solid State Voltage Regulator
Generac NP-50LPG Recreational Vehicle Generator
HIGH TEMPERATURE
SWITCH
LOW OIL PRESSURE SWITCH
GENERAC®
CORPORATION

11
Recreational Vehicle Generator
The voltage regulator also incorporates a “voltage surge pro-
tectioncircuit.” This circuit preventstroublesomesurgesinthe
generatorAC output voltage. Voltage surge is a common cause
of damage to electronic equipment.
25-HOUR BREAK IN PERIOD
The first 25 hours of operation is the break-in period for the
generator. Properly breaking in the generator is essential to
minimizefuelconsumptionandprovide maximum engine per-
formance. During this 25-hour break in period, follow this
procedure:
• Run the unit at varying electrical loads, to help seat engine
piston rings properly.
• For the 75-hour operation following the break in period,
avoid light electrical loads. Load the generator at 50% (or
more) of its rated wattage capacity. Repeated light loads
during these 75 hours can cause improper seating of engine
piston rings, resulting in blowby and high oil consumption.
• Check engine oil level frequently. Add oil if needed. It is
normal for the generator engine to consume more oil than
is normal until the piston rings have properly seated.
• Afteroperatingtheunitfor 25 hours,completethetasksrec-
ommended under “25-Hour Check Up.”
25-HOUR CHECK UP
After the 25-hour break-in period, contact an authorized ser-
vice facility for the following maintenance. The vehicle owner
is responsible for any charges:
• Change engine crankcase oil and oil filter.
Check oil level.
• Inspect cooling and ventilation openings.
Check engine carburetor.
• Check engine ignition system.
• Inspect entire electrical system.
• Inspect the engine exhaust system.
OPERATION IN HIGH GRASS
OR BRUSH
WARNING: NEVER OPERATE THE GENERATOR
WHILE THE VEHICLE IS PARKED IN HIGH GRASS,
WEEDS, BRUSH OR LEAVES. SUCH MATERIALS
CAN IGNITE AND BURN FROM THE HEAT OF THE
EXHAUST SYSTEM. THE GENERATOR EXHAUST
BECOMES EXTREMELY HOT DURING OPERATION
AND REMAINS HOT FOR A LONG TIME AFTER IT
HAS SHUT DOWN.
ATTENTION REQUIRED AFTER SUB-
MERSION
If the recreational vehicle generator has been submerged in
water, it must NOT be started or operated. Following any sub-
mersion in water, have an authorized Generac Service Facility
thoroughly clean and dry the generator.
OPERATING PRECAUTIONS
Never operate the generator set while the vehicle is parked
over dry leaves, dry grass or any other combustible substance.
The generator’s exhaust system becomes extremely hot and
can cause fire if it is too close to combustible materials.
The generator’s exhaust system gives off DEADLY carbon
monoxide gas. this dangerous gas, if breathed in sufficient
concentrations, can cause unconsciousness and even death.
never operate the generator set with the vehicle inside any
garage or enclosed area. Never operate the generator if it has
a leaky exhaust system. Close windows in the vicinity of the
generator exhaust outlet and take any other steps to prevent
exhaust gases from entering rooms or areas occupied by
people or animals.
EFFECTS OF MOISTURE AND DIRT
Keep the generator set as clean and dry as possible. Protect
the unit against excessive dust, dirt, corrosive vapors, road
splash, etc. Permitting dirt and moisture to accumulate on
generator windings will have an adverse effect on the insula-
tion resistance of those windings.
When moisture is allowed to remain in contact with windings,
some of the moisture will be retained in voids and cracks in the
insulation. This causes a reduced insulation resistance and
will eventually cause problems. Dirt will make the problem
worse, since dirt tends to hold moisture in contact with wind-
ings. Salt (as from sea air) will also worsen the problem since
it tends to absorb moisture from the air. Salt and moisture,
when combined, form a good electrical conductor.
Generac NP-50LPG Recreational Vehicle Generator
GENERAC®
CORPORATION

12
Recreational Vehicle Generator
FUEL REQUIREMENTS
The “NP” series generator is equipped with a liquefied petro-
leum (LP) gas fuel system. LP gas is usually supplied as a
liquid in pressure tanks.
“NP” series generators require a “vapor withdrawal” type fuel
system. This type of gaseous fuel system uses the vapors
forming above the liquid fuel in the storage tank. Air temper-
aturearoundthestoragetankmustbe high enough to sustain
adequatefuelvaporization. Incolderclimates,youmay need
to use an independent heat source to be sure the fuel suffi-
ciently vaporizes in the storage tank.
LP gas may consist of propane, butane or a mixture of two
gases. Using fresh HD-5 LP is recommended. Fuel should
notcontainmorethan2.5%butane. Propane vaporizesattem-
peratures as low as -20°F (-29°C), but butane returns to its
liquid state when the temperature drops below about 32°F
(0°C). For that reason, a higher ratio of propane is desired in
the gas mixture when temperatures drop below freezing.
FUEL CONSUMPTION
(CUBIC FEET PER HOUR)
Thefollowingliststheapproximate amount of fuel the unit con-
sumes at 100% rated load. Actual fuel consumption may
vary depending on BTU content of fuel, applied load, ambi-
ent conditions, engine condition, etc.
Propane ..............................................47 cubic ft. per hour
ENGINE OIL REQUIREMENTS
Useahighqualitydetergentoilclassified“For Service SF” and
with an oil viscosity rating of SAE 10W-30 oil. Do not pour in
any additives to the recommended oil. Engine crankcase
capacity is 1.5 U.S. quarts (1.4 liters). See MAINTENANCE
section for oil level check and filling procedures.
SPECIFICATIONS
ENGINE
Type of Engine ....................................................GN-410, single-cylinder
Cooling Method ........................................................................Air-cooled
Rated Horsepower..........................................................15 at 4200 RPM
Displacement ..................................................................................407cc
Cylinder Block ........................................Aluminum with cast iron sleeve
Type of Governor................................................Mechanical, fixed speed
Air Cleaner ....................................Paper element with foam pre-cleaner
Starter..........................................................................12 volt DC electric
Ignition System........................................................................Solid State
Recommended Spark Plugs
Champion................................................................................RC12YC
AC ................................................................................................R45S
Autolite ..............................................................................................65
Spark Plug Gap........................................................0.030 inch (0.76mm)
GENERATOR
Rotor RPM ........................................................................................3600
Rotor Poles..............................................................................................2
Engine RPM......................................................................................2571
Rated Maximum Continuous
AC Output ................................................................4500 watts (4.5 kW)
Voltage ......................................................................................120 volts*
Rated Maximum Continuous AC Current............................37.5 amperes
Phase ..............................................................................................single
Frequency....................................................................................60 Hertz
Weight ...................................................................... 197 pounds (93 kg)
Length ...................................................................... 25 inches (635mm)
Width...................................................................... 18.5 inches (470mm)
Height ....................................................................15.75 inches(400mm)
* The unit is reconnectable to 120 and/or 240 volts, dual voltage output.
Rated maximum continuous current at 240 volts is 18.8 amps.
Generac NP-50LPG Recreational Vehicle Generator
GENERAC®
CORPORATION

13
Recreational Vehicle Generator
This section includes information about simple maintenance
which includes the following tasks.
• Checking engine oil level
• Changing engine oil
• Changing oil filter
• Clean or change the air cleaner
• Cleaning the air intake screen
• Cleaning spark plug
CHECKING ENGINE OIL LEVEL
Check engine crankcase oil level at least every eight hours of
operation, or before you use it.
Be sure the generator is as level as possible.
• Remove OILDIPSTICK (Figure 7) and wipe it dry with clean,
lint-free cloth.
• Install and tighten oil dipstick then remove again.
• Oillevelshouldbeatthedipstick “FULL” mark.Ifnecessary,
add oil to the “FULL” mark only. DO NOT FILL ABOVE THE
“FULL” MARK.
• Install and tighten oil dipstick before operating the engine.
NOTE: See “Engine Oil Requirements” on Page 12 for rec-
ommended oils.
Figure 7 —Oil Dipstick and Oil Fill Cap
CHANGE ENGINE OIL
Change engine oil after the first 25 hours of operation (after
the 25-hour break-in period, Page 11). Thereafter, change oil
every 50 operating hours. Change oil more frequently if oper-
ating consistently under heavy load or at high ambient
temperatures. To change oil, proceed as follows:
• Run engine for at least 5 minutes, then shut down.
• With engine still warm, remove oil drain cap from oil drain
hose (Figure 8). Drain oil completely into a suitable con-
tainer.
Figure 8 — Location of Oil Drain Cap
• When oil has drained, install and tighten oil drain cap.
• Remove oil fill cap and fill crankcasewiththerecommended
oil(seePage 12). The engine crankcasecanholdabout1.4
liters. DO NOT FILL ABOVE “FULL” MARK.
• Install and tighten oil dipstick and oil fill cap before operat-
ing engine.
CHANGE OIL FILTER
Change engine oil filter after the first 25 hours of operation,
every 100 operating hours thereafter.
• Turn oil filter counterclockwise to remove (Figure 9).
• Coat gasket of new filter with engine oil.
• Turnnewfilter clockwise until its gasketcontactslightlywith
thefilteradapter. Thentightenwithanadditional3/4toone
turn by hand.
• Run engine and check for leaks.
NOTE: Check oil level and fill to full mark after checking for
leaks. Filter will retain some oil.
Figure 9 — Engine Oil Filter
Generac NP-50LPG Recreational Vehicle Generator
OIL DIPSTICK
GENERAC®
CORPORATION
OIL FILL CAP
OIL DRAIN CAP

14
Recreational Vehicle Generator
ENGINE AIR CLEANER
Clean and re-oil the foam pre-cleaner every three months or
every 25 operating hours, whichever comes first. Service
morefrequentlyifoperatingunderextremely dusty or dirty con-
ditions (Figure 10):
• Remove both screws to loosen cover.
• Remove the COVER, FOAM PRE-CLEANER and PAPER
FILTER.
• Remove foam pre-cleaner from cover.
• Wash foam pre-cleaner in liquid detergent and water.
• Wrap foam pre-cleaner in a cloth and squeeze dry.
• Saturatefoam pre-cleaner in engine oil. Squeezetoremove
excess oil (Do not twist foam pre-cleaner).
• Install foam pre-cleaner into cover, followed by paper filter.
• Install cover, foam pre-cleaner and paper filter.
• Tighten both screws to retain.
Once each year or every 100 hours of operation (whichever
comes first), replace the paper filter. The new replacement
filter must be a flame retardant type.
Figure 10 — Engine Air Cleaner
CLEAN OR REPLACE AIR FILTER
Remove air cleaner cover; then remove foam pre-cleaner
(service if necessary) and remove paper filter.
Clean air filter by tapping it gently on a solid surface. If the
filter is too dirty, replace it with a new one. Dispose of the
old filter properly.
Clean air cleaner cover then insert pre-cleaner into cover.
Next insert new paper filter into cover to hold pre-cleaner
in place and assemble all of them to the base of the air
cleaner.
CLEAN AIR INTAKE SCREEN
Clean all foreign material from air intake screen (Figure 11)
at least once every 100 hours of operation. Clean more often
if necessary.
Inspect the area around the generator exhaust muffler peri-
odically and remove all grass leaves, dirt, etc.from this area.
Figure 11 — Cleaning Air Intake Screen
ENGINE SPARK PLUG
Clean engine spark plug and set gap to 0.030 inch (0.76mm)
every 100 hours of operation (Figure 12). Clean by scraping
or wire brushing and washing with commercial solvent. DO
NOT BLAST CLEAN SPARK PLUG.
CAUTION: Sparking can occur if wire terminal
does not fit firmly on spark plug terminal end. If
necessary, reform wire terminal to obtain a tight fit.
Figure 12 — Setting Spark Plug Gap
Generac NP-50LPG Recreational Vehicle Generator
CLEAN AREAS
GENERAC®
CORPORATION

15
Recreational Vehicle Generator
SPARK ARRESTOR MUFFLER
If the generator is not equipped with a spark arrestor exhaust
muffler and is to be used on any forest covered, brush cov-
ered or grass covered unimproved land, you may have to
installaspark arrestor. The sparkarrestormust be maintained
in effective working order by the vehicle owner/operator.
For assistance in ordering, installing and maintaining spark
arrestor exhaust mufflers, contact your nearest authorized
service facility.
Exhaust mufflers supplied by Generac are spark arrestor
types. Generac exhaust muffler for recreational vehicle gen-
eratorsdonothaveaspark arrestor screen, butareofthemore
efficient “toroid” or “swirl” type. To remove carbon and com-
bustion deposits from such mufflers, remove the PLUG from
the muffler and run engine for about 15 minutes. Shut engine
down, let the muffler cool and install the plug.
WARNING: BE SURE TO RE-INSTALL THE PLUG
FROM THE MUFFLER TIGHTLY. ENGINE VIBRATION
COULD CAUSE A LOOSE PLUG TO FALL OUT.
WITHOUT THE PLUG IN PLACE, HOT ENGINE
EXHAUST IS DIRECTED OUT THE OPENING. THIS
HOT EXHAUST, DEPENDING ON THE INSTALLA-
TION, COULD BE DIRECTED TO AREAS NOT ABLE
TO WITHSTAND THE EXTREME HEAT SUCH AS
WOODEN FLOOR BOARDS OR OTHER FLAMMA-
BLE MATERIAL. THIS COULD RESULT IN A FIRE.
CLEANING THE GENERATOR
Keep your generator set as clean and dry as possible. Dirt
and moisture that are permitted to accumulate on electrical
windings have an adverse affect on the insulation resistance
of those windings.
Moisturethatisallowedto remain in contact with windings will
be retained in voids and cracks of the windings. Dirt makes
theproblemworse,sinceittendstoholdthemoistureintocon-
tact with the windings. Salt, as from sea air, worsens the
problem since it tends to absorb moisture from the air. The
combinationofsaltandmoisturemakesa good electricalcon-
ductor.
CAUTION! Do NOT use a forceful spray of water to
clean the generator. Water will enter the generator
interior and cause problems, and may also conta-
minate the generator fuel system.
BATTERY
All lead-acid storage batteries will discharge when not in use.
The generator battery should be inspected as follows:
ONCE WEEKLY
Inspect battery posts and cables for tightness, corrosion.
Clean and/or tighten as needed.
Also check battery fluid level, and, if necessary, fill with DIS-
TILLED WATER ONLY. DO NOT USE TAP WATER IN
BATTERY.
EVERY SIX MONTHS
Have battery state of charge and condition checked. This
should be done with an automotive type battery hydrometer.
DANGER: STORAGE BATTERIES GIVE OFF
EXPLOSIVE HYDROGEN GAS. THIS GAS CAN
FORM AN EXPLOSIVE MIXTURE AROUND THE
BATTERY FOR SEVERAL HOURS AFTER CHARG-
ING. 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.
DANGER: BATTERY ELECTROLYTE FLUID IS AN
EXTREMELY CAUSTIC SULFURIC ACID SOLUTION
THAT CAN CAUSE SEVERE BURNS. DO NOT
PERMIT FLUID TO CONTACT EYES, SKIN, CLOTH-
ING, PAINTED SURFACES, ETC. WEAR
PROTECTIVE GOGGLES, PROTECTIVE CLOTHING
AND GLOVES WHEN HANDLING A BATTERY. IF
YOU SPILL THE FLUID, FLUSH THE AFFECTED
AREA IMMEDIATELY WITH CLEAR WATER.
DANGER: DO NOT USE ANY JUMPER CABLES
OR BOOSTER BATTERY TO CRANK AND START
THE GENERATOR ENGINE. IF ANY BATTERY HAS
DISCHARGED, REMOVE IT FOR RECHARGING.
Generac NP-50LPG Recreational Vehicle Generator
GENERAC®
CORPORATION

16
Recreational Vehicle Generator
MAJOR SERVICE MANUAL
To obtain a service manual for your generator, order it from
your dealer/distributor or contact the factory. Be sure to iden-
tify your MODEL NUMBER and SERIAL NUMBER.
DRIVE BELT
The engine drives the generator rotor by means of a pulley
anddrivebeltarrangement.The drive belt and pulleysarewar-
ranted for the life of the generator. Drive belt tension was
properly adjusted before the unit was shipped from the fac-
tory. If you suspect that drive belt tension is incorrect, contact
an authorized service facility.
EXERCISING THE GENERATOR
Generac recommends that you start and operate the genera-
tor at least once every seven days. Let the unit run for at least
30 minutes to “exercise” the engine.
OUT OF SERVICE PROTECTION
If you cannot exercise the generator every seven days and it
is to be out of service longer than 30 days, prepare the gen-
erator for storage as follows:
• Start the engine and let it warm up.
• Close the fuel shutoff valve in the fuel supply line and let
the engine “run out of fuel.”
• Whiletheengineisstillwarm from running,drainthe oil com-
pletely. Refill crankcase with SAE 10W30 oil having API
classification “For Service SF.”
• Attach a tag to the engine indicating the viscosity and clas-
sification of the oil in the crankcase.
• Remove spark plug and pour about two or three table-
spoons of clean, fresh engine oil into spark plug threaded
opening. Crank engine several times to distribute oil, then
install and tighten spark plug.
• Remove the battery and store in a cool, dry room on a
woodenboard.Neverstore the battery on concrete or earth
floors.
• Clean and wipe the entire generator.
RETURN THE UNIT TO SERVICE
AFTER STORAGE
To return the unit to service after storage, proceed as follows:
• Check tag on engine for oil viscosity and classification.
Verify that the correct recommended oil is used in engine.
If necessary, drain and refill with proper oil.
• Check battery. Fill all cells to the proper level with distilled
water. DO NOT USE TAP WATER IN THE BATTERY.
Recharge battery to 100% state of charge, or, if defective,
replace the battery.
• TurnOFFallelectrical loads, add fuel if necessary, then start
the engine.
• Let the engine warm up.
• Apply electrical loads to at least 50% of the unit’s rated
wattage capacity.
• When engine is thoroughly warmed up, shut it down.
THE GENERATOR IS NOW READY FOR SERVICE.
Generac NP-50LPG Recreational Vehicle Generator
GENERAC®
CORPORATION

17
TROUBLESHOOTING POINTS
PROBLEM CAUSE CORRECTION
Engine won’t crank. 1. 15 amp fuse blown. 1. Replace fuse.
2. Loose, corroded or defective 2. Tighten, clean or replace
battery cables as necessary.
3. Battery is discharged or defective. 3. Recharge or replace battery.
4. Defective starter contactor. 4. Replace if defective.
5. Defective starter motor. 5 Replace if defective.
6. Defective Controller circuit board 6. Replace if defective.
Engine cranks but won't start 1. Out of fuel 1. Replenish fuel.
2. Fuel shutoff valve is closed. 2. Open fuel shutoff valve.
3. Defective Controller circuit board 3. Replace if defective.
4. Spark plug defective. 4. Clean, regap or replace plug.
5. Defective ignition coil on engine 5. Replace if defective.
6. Defective carburetor 6. Replace if defective.
7. Dirty air cleaner. 7. Clean or replace elements as
needed.
8. Fuel solenoid is defective. 8. Replace or repair.
Engine starts hard, runs rough. 1. Dirty air cleaner. 1. Clean or replace elements as
needed.
2. Defective spark plug. 2. Clean, regap or replace plug.
3. Defective ignition coil. 3. Replace if defective.
Engine starts, shuts down when 1. Engine oil level is low. 1. Check oil and add oil as needed.
Start/Stop switch is released. 2. Engine is overheated. 2. Check cooling system for blockage.
3. Defective Low Oil Pressure Switch 3. Replace defective switch.
4. Defective Controller circuit board. 4. Replace defective board.
No AC output from generator. 1. Check main line circuit breaker. 1. Reset to ON or CLOSED.
2. Transfer switch (if so equipped) is set 2. Reset transfer switch.
to wrong position.
3. Failure in vehicle electrical system. 3. See vehicle manual.
4. Generator component failure. 4. Contact an authorized service
facility.
Recreational Vehicle Generator
Generac NP-50LPG Recreational Vehicle Generator
GENERAC®
CORPORATION

ELECTRICAL DATA Drawing No. 94210
18
Recreational Vehicle Generator
Generac NP-50LPG Recreational Vehicle Generator
GENERAC®
CORPORATION

19
Recreational Vehicle Generator
Generac NP-50LPG Recreational Vehicle Generator
ELECTRICAL DATA Drawing No. 94210
GENERAC®
CORPORATION

20
Recreational Vehicle Generator
Generac NP-50LPG Recreational Vehicle Generator
EXPLODED VIEW — BASE AND PULLEYS Drawing No. 95865
GENERAC®
CORPORATION