Generac Power Systems NP-40G User Manual

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Manual Part No. 94468-A

SERVICE

Manual

COMPUTER

CONTROLLED

VARIABLE

SPEED RV

GENERATORS

Series NP-30G and NP-40G

P. O. Box 8 PH ONE: (414) 544-4811

Printed In U.S.A.

Waukesha, Wisconsin 53187

_________

FA X: (414) 544-4851

REVISED: 05/16/96

SAFETY

Throughout this publication, ’DANGERl" and "CAUTiONI" blocks are used to alert the mechanic to special

Instructions concerning a particular service or operation that might be hazardous if performed Incorrectly or carelessly. PAY CLOSE ATTENTION TO THEM.

DANGER!

UNDER THIS HEADING WILL BE FOUND SPECIAL INSTRUCTIONS WHICH, IF NOT COMPLIED WITH, COULD RESULT IN PERSONAL INJURY OR DEATH.

CAUTION!

Under this heading will be found special instructions which, if not complied with, couid result in damage to equipment and/or property.

These ‘Safety Alerts” alone cannot eliminate the hazards that they signal. Strict compliance with these special

Instructions plus ‘common sense” are major accident prevention measures.

NOTICE TO USERS OF THIS MANUAL

This SERVICE MANUAL has been written and published by Generac to aid our dealers’ mechanics and company

service personnel when servicing the products described herein.

It Is assumed that these personnel are familiar with the servicing procedures for these products, or like or similar products manufactured and marketed by Generac. That they have been trained in the recommended servicing procedures for these products. Including the use of common hand tools and any special Generac tools or tools from other suppliers.

Generac could not possibly know of and advise the service trade of all conceivable procedures by which a service might be performed and of the possible hazards and/or results of each method. We have not undertaken any such wide evaluation. Therefore, anyone who uses a procedure or tool not recommended by Generac must

first satisfy himself that neither his nor the products safety will be endangered by the service procedure selected.

All information. Illustrations and specifications in this manual are based on the latest product information

available at the time of publication.

When working on these products, remember that the electrical system and engine Ignition system are capable

of violent and damaging short circuits or severe electrical shocks. If you intend to perform work where electrical terminals could be grounded or touched, the battery cables should be disconnected at the battery.

Any time the Intake or exhaust openings of the engine are exposed during service, they should be covered to

prevent accidental entry of foreign material. Entry of such materials will result In extensive damage when the engine Is started.

During any maintenance procedure, replacement fasteners must have the same measurements and strength as

the fasteners that were removed. Metric bolts and nuts have numbers that indicate their strength. Customary bolts use radial lines to indicate strength while most customary nuts do not have strength markings. Mismatched or Incorrect fasteners can cause damage, malfunction and possible injury.

REPLACEMENT PARTS

Components on Generac recreational vehicle generators are designed and manufactured to comply with

Recreational Vehicle Industry Association (RVIA) Rules and Regulations to minimize the risk of fire or explosion. The use of replacement parts that are not In compliance with such Rules and Regulations could result In a fire or explosion hazard. When servicing this equipment it is extremely important that all components be properly Installed and tightened. If improperly Installed and tightened, sparks could ignite fuel vapors from fuel system

leaks.

PART

TITLE

SERVICE

MANUAL

COMPUTER

CONTROLLED

VARIABLE

SPEED RV

GENERATORS

Series NP-30G and NP-40G

1 2 3

5 6 7 TROUBLESHOOTING

THE AC GENERATOR

ENGINE MECHANICAL

GASOLINE FUEL SYSTEM

GASEOUS FUEL SYSTEM

ENGINE OIL & COOLING SYSTEM

ENGINE ELECTRICAL SYSTEM

SPECIFICATIONS & CHARTS

Part 1

THE AC

GENERATOR

COMPUTER

CONTROLLED

VARIABLE

SPEED RV

GENERATORS

Series NP-30G and NP-40G

SECTION

1.2

1.3

1.4

1.5

1.6

1.7

TITLE

TaEnE!53tT5i?TOnï55mÇÏTRB"

GENERATOR MAJOR COMPONENTS

OPERATIONAL ANALYSIS

INSULATION RESISTANCE

COMPONENTS TESTING

CONTROL PANEL

SHEET METAL

Section 1.1- GENERATOR FUNDAMENTALS

Magnetism

Magnetism can be used to produce electricity and

electricity can be used to produce magnetism.

Much about magnetism cannot be explained by our present knowledge. However, there are certain patterns of behavior that are known. Application of these behavior patterns has led to the development of generators, mo tors and numerous other devices that utilize magnetism to produce and use electrical energy.

See Figure 1. The space surrounding a magnet Is permeated by magnetic lines offeree called "flux“. These lines offeree are concentrated at the magnet’s north and south poles. They are directed away from the magnet at Its north pole, travel In a loop and re-enter the magnet at Its south pole. The lines of force form definite patters which vary In Intensity depending on the strength of the magnet The lines of force never cross one another. The area surrounding a magnet In which Its lines offeree are effective Is called a "magnetic field".

Like poles of a magnet repel each other, while unlike poles attract each other.

Electromagnetic Fields

AM conductors through which an electric current Is flowing have a magnetic field surrounding them. This field Is always at right angles to the conductor. If a compass Is placed near the conductor, the compass needle will move to a right angle with the conductor. The following rules apply:

NOTE: The "right hand rule" Is based on the "current flow" theory which assumes that current flows from positive to negative. This Is opposite the "electron" theory, which states that current flows from negative to positive.

Electromagnetic induction

An electromotive force (EMF) or voltage can be pro duced In a conductor by moving the conductor so that it cuts across the lines of force of a magnetic field.

Similarly, if the magnetic lines of force are moved so that they cut across a conductor, an EMF (voltage) will be produced In the conductor. This Is the basic principal of the revolving field generator.

Figure 3, below. Illustrates a simple revolving field generator. The permanent magnet (Rotor) Is rotated so that its lines of magnetic force cut across a coll of wires called a Stator. A voltage Is then Induced into the Stator windings. If the Stator circuit Is completed by connecting a load (such as a light bulb), current will flow in the circuit and the bulb will light.

□ The greater the current flow through the conductor,

the stronger the magnetic field around the conduc tor.

□ The Increase In the number of lines of force Is di

rectly proportional to the Increase In current flow and the field Is distributed along the full length of the conductor.

D The direction of the lines of force around a conduc

tor can be determined by what Is called the "right hand rule". To apply this rule, place your right hand around the conductor with the thumb pointing In the direction of current flow. The fingers will then be pointing in the direction of the lines of force.

Alternating Current

A simple generator consists of a coil of wires called a Stator and a magnetic field called a Rotor. As the Rotor’s magnetic field cuts across the Stator coll, a voltage Is induced into the Stator windings. The amount of Induced voltage is equal to the strength of the magnetic field.

Page 1.1-1

Section 1.1- GENERATOR FUNDAMENTALS

Alternating Current (Continued)

See Figure 4. The current alternates according to the position of the Rotor’s poles in relation to the position of the Stator. At 0* and again at 180*, no current flow Is produced. At 90’ of Rotor rotation, current flow reaches a maximum positive value. Rotor rotation to 270’ brings another maximum flow of current. However, at 270’ the current flow has reversed In polarity and now flows in the opposite direction.

Electrical Units

AMPERE;

The rate of electron flow in a circuit is represented by the AMPERE. The ampere is the number of electrons flowing past a given point at a given time. One AMPERE Is equal to Just slightly more than six thousand million billion electrons per second.

With alternating current (AC), the electrons flow first In one direction, then reverse and move In the opposite direction. They will repeat this cycle at regular intervals. A wave diagram, called a “sine wave“ shows that current goes from zero to maximum positive value, then reverses and goes from zero to maximum negative value. Two reversals of current flow Is called a cycle. The number of cycles per second Is called frequency and is usually stated in "Hettz".

Page 1.1-2

VOLT:

The VOLT is the unit used to measure electrical PRESSURE, or the difference In electrical potential that causes electrons to flow. Very few electrons will flow when voltage is weak. More electrons will flow as voltage becomes stronger. VOLTAGE may be consdiered to be a state of unbalance and current flow as an attempt to regain balance. One volt is the amount of EMF that will cause a current of 1 ampere to flow through 1 ohm of resistance.

Figure 6. Electrical Units

Conductor of a Circuit

AMPERE - Unit measuring rate of

OHM - Unit measuring resistance

or opposition to flow

current flow (nunfcer of elec trons past a given point)

■ VOLT - Unit measuring force or _____

difference in potential

causing current flow

Section 1.1- GENERATOR FUNDAMENTALS

OHM:

The OHM Is the unit of RESISTANCE. In every circuit there Is s natural resistance or opposition to the flow of electrons. When an EMF Is applied to a complete circuit, the electrons are forced to flow In a single direction rather than their free or orbiting pattern. The resistance of a conductor depends on (a) Its physical makeup, (b) Its cross-sectional area, (c) Its length, and (d) Its temper ature. As the conductor’s temperature Increases, Its re sistance Increases In direct proportion. One (1) ohm of resistance will permit one (1) ampere of current to flow when one (1) volt of electromotive force (EMF) Is applied.

Ohm’s Law

A definite and exact rela tionship exists between VOLTS, OHMS and AMPERES. The value of one can be calcu lated when the value of the other two are known. Ohm’s

Law states that In any circuit

the current will Increase when voltage Increases but resis tance remains the same, and current will decrease when re

sistance Increases and volt

age remains the same.

If AMPERES Is unknown while VOLTS and OHMS are

known, use the following formula:

i AMPS

\(l)

OHMS j

(R)y

The magnetic field around the conductor Induces elec

tromotive forces that cause current to keep on flowing while voltage drops. The result Is a condition In which voltage leads current When a conductor Is formed Into a coll, the magnetic lines of force are concentrated In the center of the coll. This Increased density causes an Increase In magnetically Induced EMF without Increas ing current Thus, colls cause Inductive reactance.

Inductive reactance can also be caused by placing an

Inductlonmotoronthe circuit which utilizes the current’s magnetic field for excitation.

AMPERESs VOLTS

■ÖHMS"

If VOLTS is unknown while AMPERES and OHMS are

known, use the following formula:

VOLTS 3 AMPERES X OHMS If OHMS Is unknown but VOLTS and

AMPERES are unknown, use the following:

OHMS: VOLTS

AMPERES

Reactance in AC Circuits

GENERAL:

When direct current (DC) Is flowing, the only opposi

tion to current flow that must be considered is resistance (ohms). This Is also true of alternating current (AC) when only resistance type loads such as heating and lamp elements are on the circuit In such a case, current will be In phase with voltage- that Is, the current sine wave will coincide In time with the voltage sine wave.

However, two factors In AC circuits called INDUCTIVE

and CAPACITIVE REACTANCE will prevent the voltage and current sine waves from being In phase.

INDUCTIVE REACTANCE:

This condition exists when current lags behind volt

age (Figure 8). As current flows In a circuit, magnetic

lines offeree are created at right angles to the conductor. The continuous changes In current value (from positive to negative) cause these magnetic lines to collapse and

build up continuously.

CAPACITIVE REACTANCE:

This condition occurs when current leads voltage (Fig

ure 9). It might be thought of as the ability to oppose change In voltage. Capacitance exists In a circuit when certain devices are (a) capable of storing electrical

charges as voltage Increases and (b) discharging these

stored charges when the voltage decreases.

Section 1.1- GENERATOR FUNDAMENTALS

introduction to CCG’s

WHAT IS A "CCG"?:

The initials “CCG” stand for “computer con

trolled generator“. Such units are different from conventional generators in that the performance of the engine and AC generator are more accurately matched over a wide range of power needs. The CCG’s provide greater efficiency of both the engine and the generator while maintaining electrical out put within an acceptable voltage and frequency band.

CCG units have the ability to operate the engine over a wide range of speeds, while conventional generators will deliver correct AC frequency and voltage only at a fixed rpm. The unit’s electrical output is fed through an AC-AC converter which reconstructs electrical waveforms to the correct output frequency.

Unlike conventional AC generators, the CCG can match engine speed to load requirements. This provides several advantages, as follows:

П Smaller engines can be used to produce more

power than on a conventional generator, since it can be allowed to run at a higher speed.

□ When the load is reduced, the engine can run

at slower than the usual speeds. This improves fuel economy and reduces engine noise.

□ The CCG unit can be operated closer to its peak

power point at all times, because output volt

age and current are functions of engine speed. This allows fora much more compact generator design.

CCG SYSTEM OVERVIEW:

Figure 10 is a block diagram of the CCG system.

The major elements of the system are represented

in the diagram. Operation of the system may be described briefly as follows:

1. The engine is directly coupled to a permanent magnet type Rotor, so the Rotor runs at the same speed as the engine.

2. As the Rotor turns. Its magnetic field cuts across

the Stator windings to induce a voltage into the Stator.

a. The Stator is a 2-phase type with center tap. b. Stator AC output frequency Is between 336 and

540 Hertz. This corresponds to engine speeds of 2520 to 4050 rpm.

c. The load requires a nominal AC frequency of 60 Hertz. Thus, the generated frequency Is six to nine times the desired range.

3. A Frequency Converter changes the high fre quency output to a useful frequency, I.e., one that is compatible with load requirements of about 60 Hertz.

4. A Voltage Detector circuit senses load voltage and signals a System Control circuit.

5. The System Control circuit establishes the RE

QUIRED ENGINE SPEED for correct voltage and

delivers an output to an Engine Controller.

6. The Engine Controller adjusts the engine’s Throttle to change engine speed and establish the correct AC output voltage.

7. The following facts should be apparent:

□ LOAD FREQUENCY IS CONTROLLED BY THE

“FREQUENCY CONVERTER“ DEVICE.

□ VOLTAGE IS CONTROLLED BY A “SYSTEM

CONTROL“ CIRCUIT WHICH CHANGES EN GINE SPEED TO MAINTAIN A CONSTANT

VOLTAGE AT VARYING ELECTRICAL LOADS.

Page 1.1-4

Section 1.1- GENERATOR FUNDAMENTALS

Why Variable

Most electrical loads will operate satisfactorily only within a relatively small voltage band. In order to provide useful voltage at larger load currents, It is necessary to increase engine speed.

In conventional AC generators, some form of voltage regulation Is needed to provide correct voltage in the full range of load current. This Is often accomplished by regulating excitation cur rent to the Rotor (fíelo) which then regulates the strength of the Rotor’s magnetic field. The voltage

Induced Into the Stator windings Is proportional to

the strength of the Rotor’s magnetic field.

Speed Control?

The CCG uses a Rotor having a fixed and perma

nent magnetic field. The strength of this magnetic

field Is fixed and cannot be regulated.

The output voltage on CCG generators tends to

droop with Increasing electrical loads. The SYS TEM CONTROLLER maintains a constant AC out

put voltage by Increasing engine and Rotor speed

as the load current increases, to offset this Inherent voltage droop.

The SYSTEM CONTROLLER also selects the cor rect number of generator pulses which are com bined to form each 60 Hertz "half-cycle“.

Section 1.1- GENERATOR FUNDAMENTALS

Page 1.1-6

Section 1.2- MAJOR GENERATOR COMPONENTS

Introduction

Major components of the generator proper are shown in Figure 1, beiow. Externai sheet metal and other unrelated components are omitted from the drawing for clarity. These parts are:

ITEM

1 2 3 4 5 6 7 8 9

NOMENCLATURE

Upper Fan Housing

Upper Cooling Fan

Permanent Magnet Rotor

Rotor Hub

Stator Retaining Ring

Stator Assembly

Stator Adapter

Engine

Lower Fan & Flywheel

Stepper Motor

Upper Fan Housing

As its name implies, this component houses and

shields the upper cooling fan. See Figure 1, Item

Upper Cooling Fan

The Cooling Fan draws air Into the generator

through slots in the Upper Fan Housing. It Is fas tened to and rotates with the Permanent Magnet

Rotor.

Permanent Magnet Rotor

Sixteen permanent magnets have been affixed to

the Rotor. A starter ring gear is welded to the Rotor. The Rotor and Hub are balanced at the fac tory as an assembly and must be replaced as an assembly.

NOTE: The hub MUST be properly aligned during

reassembiy. The mounting bolt, housing opening and magnet must be properly aligned. In addition, match marks between the Hub and Rotor must be' aiigned as indicated by an “ALIGN MARKS FOR BALANCE” decal. During assembiy, use care to avoid damage to the Ignition Sensor.______________

DANGERI

THE PERMANENT MAGNET ROTOR PRODUCES AN EXTREMELY STRONG MAGNETIC FORCE.

USE CARE DURING INSTALLATION TO AVOID PINCHED FINGERS.

Page 1.2-1

Section 1.2- MAJOR GENERATOR COMPONENTS

Rotor Hub

See Figure 2. The Rotor Hub Is balanced with the Rotor and must be replaced with the Rotor as an assembly. Part of the engine ignition system is pressed onto the Hub and can be replaced only as part of the Rotor and Hub assembly.

Stator Retaining Ring

The Stator Retaining Ring is made of dIe-cast aluminum. Four hex head capscrews with lockwashers pass through holes in the Retaining Ring, to retain the Stator Assembly to the Stator

Adapter (Item 7, Figure 1).

Stator Assembly

The 2-phase Stator is made up of eight (8) wind ings, with leads brought out as shown in figure 3. Figure 4 is a schematic representation of each sta

tor winding. Note that there are four (4) power

phase windings (Leads AC2, AC1, SI2, SI1 and 11);

a timing winding (Leads TIM1 and TIM2); a power supply winding (Leads PS1, PS2); and a dual bat tery charge winding (Leads 55, 66, 77). The Stator produces a frequency of 336 to 540 Hertz, which corresponds to engine speeds between 2520 and 4050 rpm. This means the gen erated frequency is between six and nine times

the desired frequency of about 60 Hertz.

Stator Adapter

The Adapter Is retained to the engine by means of four hex head capscrews. The Stator Is retained to the Stator Adapter and Is “sandwiched'' between the Adapter and the Stator Retaining Ring.

Lower Fan & Flywheel

The Lower Fan and Flywheel are retained to the engine PTO shaft by means of a conical washer and an Ml 6-1.50 hex nut. When assembling, tighten the flywheel nut to 75 foot-pounds.

Engine

The engine is a single cyclinder, overhead valve type manufactured by Generac Corporation. De pending on the specific generator Model Number, either a GN-190 or a GN-220 engine is used on NP-30 and NP-40 RV generators.

sponse to changes In AC output voltage. Thus, In response to decreasing AC output voltages, the Motor will increase the throttle setting and engine speed will Increase. Conversely, Increasing AC output voltages will cause the Motor to decrease

throttle setting and engine speed will decrease.

Figure 3. Stator Pictorial View

-66 (BROWN)-

—77 (BROWN) T1M1 (ORANGE)

—TM2 (GRAY)

-PS1 (BROWN)-

-AC2 (YELLOW)

-AC1 (GRAY)—

-SL1 (ORANGE)—

-----

SL2 (BROWN)-------------

Figure 4. Schematic- Stator Windings

POWER PHASE 1

POWER PHASE 2

AC1 aC2

I ! I

POWER I TIMING

SUPPLY I I

PS1 PS2

C «r ® ®

-55 (BLACK)

--------

»<§)

H T1M1 (

PS2 (YELLOW)

■11 (BLUE)

---------

AC2

I (7»CT«r|

II è

SL2

Stepper Motor

The Stepper Motor (Figure 5, next page) consists of a stepper motor along with a gear and cam arrangement which allows motor movement to change the engine carburetor throttle setting. The Motor Is controlled by output signals from the Com puter Control Circuit Board, which calculates the number of steps the stepper needs to take and generates the required signals to the Motor. The circuit board signals the Motor to actuate in re

Page 1.2-2

BATTERY CHARGE

Section 1.2- MAJOR GENERATOR COMPONENTS

The Genistor

GENERAL:

See Figure 6. The GENISTOR is often called a “frequency converter“ (also see "Introduction to CCG’s“ on Page 1.1-4). its function is to change the high frequency AC output of the Stator (336-540 Hertz) to a useful frequency (about 56-60 Hertz).

The Genistor has no intelligence of Its own. It is simply a high speed switcning device which is controlled by the CCG circuit board.

Switching signals from the CCG circuit board are

also delivered to the Genistor. These signals switch the Genistor on and off as required, result

ing In a sine wave output to the load as shown in

Figure 8.

Figure 6. The dtenhtor

GENISTOR THEORY:

The purpose of a “frequency converter“ is to

divide the Stator AC output frequency by an inte gral factor to provide a useful output frequency. Each of the four half-phases of the center-tapped Stator Is Genistor-controlled.

Figure 7 shows the sine wave output from the

2-phase Stator windings. This output Is delivered to the Genistor switching module.

The CCG Circuit Board

GENERAL:

The CCG circuit board has several functions as

follows:

1. It controls the operation of the “frequency con

verter“ (Genistor).

2. It controls AC output voltage under all load requirements by controlling engine speed.

3. It protects the system against various faults.

FREQUENCY CONTROL:

The CCG board will adjust the number of alterna

tor cycles In one output cycle to control AC output frequency. The number of cycles is based on en gine rpm and the output frequency will be main tained in the 55-65 Hertz band.

The board uses a "zero crossing" detector to synchronize an internal clock. The frequency of the Stator’s waveform is measured and, with referencve to the required output frequency, a “freguency divisor" is calculated. The circuit board then signals the Genistor (frequency converter) to switch on and off at the proper times so that fre quency Is maintained in the 55-65 Hertz band.

Page 1.2-3

Section 1.2- MAJOR GENERATOR COMPONENTS

The CCG

VOLTAGE CONTROL:

The CCG circuit board utilizes a closed-loop,

proportional-derivative controller which regulates RMS voltage by changing engine speed. The sys tem maintains output voltage at about 115 volts at the lowest rpm and 120 volts up to the maximum rpm.

The board controls a Stepper Motor (Figure 5),

which moves the throttle. The board calculates the number of steps the Motor needs to take and sig nals the Motor to move. Motor movement changes

throttle position and changes In engine speed re

sult.

FAULT PROTECTION:

The CCG board has the ability to detect several

fault conditions and shut the engine down, as fol

lows:

1. Overvoltage:- If the output voltage exceeds 127

VAC for longer than 15 seconds, the board will turn AC output power off and shut the engine down.

2. Undervoitage:- If output remains below about 96 VAC longer than 15 seconds, an overload condition probably exists. The board will then turn AC output off and shut the engine down.

3. Overspeed:- if engine speed exceeds 4500 rpm, shutdown will occur.

4. Failure of the Genistor (frequency converter) will result in engine shutdown.

5. Loss of output to any circuit connected to the board will result in engine shutdown.

Circuit Board (Continued)

CIRCUIT BOARD CONI

The board Is equipped with eight (8) connection points (receptacles). These are identified as

"CONNr through "CONNS". See Figure 9.

CONNECTOR CONNI

CONNECTIONS:

FUNCTION

Six-pin connector Interconnects

with speed control Stepper Motor.

CONN2

12-pin connector is NOT used on RV units. An orange jumper wire is connected across Pins 5 & 11.

CONN3

7-pin connector interconnects with

the Genistor.

CONN4

4-pln receptacle for connection of

the Stator power supply leads

(PS1, PS2) and the Stator timing

leads (TIM1, TIM2).

CONNS Single point connection for Stator

lead No. 11 (blue).

CONN6 Interconnects with the Genistor. CONN7 Single point connector Is NOT

used on RV units.

CONNS Single point connector for Wire 18B.

Interconnects with Engine Cont

roller circuit board, allows the

CCG board to shut the engine down.

-O

-Ó

Figure 9. the CÔà Circuit Board

0 0 ^

C0NN4

CDNN8 CDNN7

CDNN5

JSl

_______________

Ì i

□

CGNN3 CDNN6

lij Itl lil Ui lli'ururuu umuuiuiuniniimui Ui'Ul uul

mfamfsifsifiifgifaifgimfiimfsimmisifCTm ijunj

■~L0r'

Page 1.2-4

Section 1.3- OPERATIONAL ANALYSIS

General

Figure 1, below, is a block diagram of the com puter controlled RV generator. The diagram la In tended only for the purpose of Illustrating genera tor operation. Refer to the actual wiring diagram for wiring interconnections.

Operational Description

1. The PERMANENT MAGNET ROTOR Is directly

coupled to the ENGINE and rotates at the same speed as the engine.

2. As the ROTOR turns, its magnetic field cuts across a number of STATOR windings, to Induce a voltage Into those windings. A voltage Is induced

Into the following STATOR windings:

a. Phase 1 and 2 of the STATOR POWER WIND

INGS (output leads AC1-AC2 and SL1-SL2).

b. The STATOR POWER SUPPLY WINDING with

output leads PS1-PS2.

c. The STATOR TIMING WINDING (output leads

TIM1-TIM2).

d. STATOR BATTERY CHARGE WINDING with

output leads 55,66 and 77.

Figure 1. Block Diagram- AC Generator System

3. STATOR BATTERY CHARGE WINDING o^ut Is delivered to the unit battery via a BATTERY CHARGE RECTIFIER (BCR) and a 1 OHM, 50 WATT RESISTOR. The circuit Is completed through the battery to frame ground and back to the BATTERY CHARGE WINDING via Wire 55.

4. STATOR TIMING WINDING output is delivered to

the CCG CIRCUIT BOARD. The circuit board mea sures the frequency of the waveform and calcu

lates a "frequency divisor" to maintain a useable

frequency to the CUSTOMER CONNECTION re

gardless of rpm.

5. The STATOR POWER SUPPLY WINDING output Is delivered to the CCG CIRCUIT BOARD. This is

the power supply for operation of the circuit board and GENISTOR.

6. STATOR POWER WINDING OUTPUT (Phase 1

and 2) Is delivered to a GENISTOR. The GENISTOR

is a nIgh-speed switching device which is con

trolled by the CCG board.

7. The CCG CIRCUIT BOARD senses voltage and

frequency and then acts to control voltage and frequency as follows:

STATOR POWER WINDING AC1-AC2

WÀ‘§Ê2

STATOR

POWER

WINDING

SL1-SL2

STATOR

POWER

SUPPLY

WINDING

PS1-PS2

STATOR

TIMING

WINDING

TIM1-TIM2

WIRE18B

.(ENGINE

SHUTDOWN)

STATOR

BATTERY

CHARGE

WINDING

66-77

MAGNETIC FIELD

PERMANENT

MAGNET

ROTOR

ENGINE

Page 1.3-1

Section 1.3- OPERATIONAL ANALYSIS

Operational Description (Continued)

a. The circuit board senses actual voltage and b. The CCG board < "compares“ it to a pre-set “reference“ voltage of about 115-120 volts AC.

0) If voltage Is low, the board will signal a STEPPER MOTOR to change engine throttle setting and In crease speed until the desired voltage level Is reached.

If voltage goes high, the board will signal the

STEPPER MOTOR to reduce engine throttle setting until the desired voltage level Is obtained.

(3) Engine speed Is variable and Is used to control output voltage and may range from about 2520 to 4050 rpm.

acting on the GENISTOR. (1) The GENISTOR is a high speed switching

device. (2) The CCG board signals the Genistor to switch

generator waveforms on and off at the proper times. In order to maintain a frequency In the 55-65 Hertz band.

8. The CCG circuit board can protect the system against some faults by shutting the engine down, wire 18B is the “engine shutdown“ lead that connectcts this system to the Engine Controller circuit board. See “FAULT PROTECTION“, Page 1.2-4.

controls AC frequency by

Page 1.3-2

Section 1.4- INSULATION RESISTANCE

Dirt and Moisture

If moisture Is permitted to remain In contact with the generator Stator windings, some of It will be retained In voids and cracks of the winding Insulation. This can eventually cause a reduction In Insulation resistance and generator output may be affected.

Winding Insulation In Generac generators Is moisture resistant. However, prolonged exposure to water, high humidity, salt air, etc., will gradually reduce the resis tance of winding Insulation.

Dirt can make the problem even worse, since It tends to hold moisture Into contact with the windings. Salt, as from sea air, can also worsen the problem, since salt tends to absorb moisture from the air. When salt and moisture combine, they make a good electrical conduc tor.

Because of the detrimental effects of water, dirt and salt, the generator should be kept as dry and as clean as possible. Stator windings should be tested periodically using a Hi-Pot tester or a Megohmmeter. If insulation resistance is low, drying of the unit may be necessary. If resistance is still low after drying, the defective Stator should be replaced.

Insuiation Resistance Testers

One kind of Insulation resistance tester Is shown in Figure 1, below. Other types are commerlally available. The type shown has a "Breakdown” lamp which turns on to indicate an Insulation breakdown during the test.

One common type of tester is the "Megohmmeter" which measures resistance in "Megohms".

NO. COLOR CONNECTS TO

U 77

66 55 SL2 SL1 AC2 AC1 PS1 TIM1 PS2 TIM2

Blue Brown Brown

Black

Brown

Orange

Yellow

Gray

Brown

Orange

Yellow

Gray

Main Circuit Breaker CB1 Battery Charge Rectifier BCR Battery Charge Rectifier BCR

Grounding Terminal

Genistor fG) Genistor (G) Genistor (G) Genistor (G)

CCG Circuit Board (CCB)

CCG Circuit Board i CCB)

CCG Circuit Board l CCB)

CCG Circuit Board (CCB)

Figure 2. Stator Leads

— 55 (BLACK)-*^)

-66 (BROWN)

— 77 (BROWN) —(ORANGE)

PS2 (YELLOW)

—TM2 (GRAY) -

-PS1 (BROWN)I (BLUE) —«0)

-AC2 (YELLOW)

-AC1 (GRAY)—

-SL1 (ORANGE)^—

CAUTION!

When using a Megohmmeter or any other tester, be sure to follow the manufacturer’s instructions carefully. All Stator leads must be isolated from other components, especially circuit boards, be fore performina tests. The high voltages used In testing Insuiation resistance will damage elec tronic components.

Stator Leads

The following leads are brought out of the Stator and

connected to various components in the unit:

-----

SL2 (BROWN)

-------------

■^0

Preparation for Tests

See Stator leads CHART above. Disconnect and Iso

late all Stator leads. ALL STATOR LEADS MUST BE DISCONNECTED AND ISOLATED BEFORE STARTING

THE TESTS.

Test Aii Stator Windings to Ground

Connect the ends of all Stator leads together. Make

sure none of the leads are touching any terminal or any

part of the generator.

Connect one Tester probe to the Junction of all Stator

leads; the other Tester probe to a clean frame ground on

the Stator. Apply a voltage of 1000 volts for about 1 second.

Follow the tester manufacturer’s Instructions care

fully. Some "Hl-Pot" testers are equipped with a "Break down" light which will turn ON to indicate an Insulation

breakdown.

"Megger" (Megohmmeter) will Indicate the "meg

s’’ of resistance. Normal Stator winding Insulation

ohms"

resistance is on the order of "millions of ohms" or "meg

ohms". The MINIMUM acceptable Insulation resistance

reading for Stators can be calculated using the following

formula.

MINIMUM INSULATION RESISTANCE (In “megohniis")

GENERATOR RATED VOLTS

------------------------------------------ +1 1000

Page 1.4-1

Section 1.4- INSULATION RESISTANCE

Test All Stator Windings to

Ground (Continued)

EXAMPLE: Generator rated voltage Is "120 VAC". Divide ■ obtain the unit Is "1.12 megohms".

120 by 1000 to obtain "0.12". Add “1" to "1.12 . Minimum Insulation resistance for

..............................................■

Test for Shorts Between Windings

Figure 2 on the previous page shows the Stator leads that are brought out of the Stator. Figure 3 is a schematic representation of the eight (8) Stator windings. To test for shorts between windings, proceed as follows:

1. Make sure all Stator output leads are isolated from each other and from the frame.

2. POWER PHASE TO TIMING WINDINGS:- Connect one tester probe to Stator lead No. 11, the other test probe to Stator lead TIM1. Apply a voltage of 1000 volts. The Tester will Indicate a breakdown if the windings are shorted together.

3. POWER PASE TO POWER SUPPLY WINDINGS: Con nect one tester probe to Stator lead No. 11, the other tester probe to Stator lead PS1. Apply 1000 volts. If a breakdown Is Indicated, the windings are shorted to gether.

4. POWER PHASE TO BATTERY CHARGE WINDINGS:Connect one tester probe to Stator Lead No. 11, the other probe to Stator lead No. 55. Apply 1000 volts. If break down Is Indicated, the windings are shorted together.

5. TIMING TO POWER SUPPLY WINDING:- Connect one tester probe to Stator lead No. TM1, the other test probe to Stator lead No. PS1. Apply 1000 volts. If breakdown is Indicated, the windings are shorted together.

6. TIMING TO BATTERY CHARGE WINDING:- Connect one test probe to Stator lead No. TIM1, the other test probe to Stator lead No. 55. Apply 1000 volts. If break down is Indicated the windings are shorted together.

7. POWER SUPPLY TO BATTERY CHARGE WINDING:Connect one test probe to Stator lead No. PS1, the other probe to Stator lead No. 55. Apply 1000 volts. If break down is indicated, the windings are shorted together.

Results of Tests

1. If testing Indicates that Stator windings are shorted to ground, the Stator should be cleaned and dried. The Insulation resistance tests should then be repeated. If, after cleaning and drying, the Stator again fails the test, replace the Stator assembly.

2. If testing Indicates that a short between windings exists, clean and dry the Stator. Then, repeat the tests. If Stator fails a second test (after cleaning and drying), replace the Stator assembly.

Cleaning the Generator

GENERAL:

If testing indicates that the insulation resistance is below a safe value, the winding should be cleaned. Proper cleaning can be accomplished only while the generator is disassembled. The cleaning method used should be determined by the type of dirt to be removed. Be sure to dry the unit after it has been cleaned. An electric motor repair shop may be able to assist with cleaning. Such shops are often experienced in special problems (sea coast, marine, wetland applications, etc.).

Figure 3. Schematic- Stator Windings

pravm ппушт|

POWER PHASE 1

POWER ^ PHASE 2

BATTERY CHARGE

AC1

SL1

POWER

SUPPLY

PS1 PS2 .

О ^ О

AC2

SL2

TIMING

TIMI T1M2

USING SOLVENTS FOR CLEANING:

A solvent is generally required when dirt contains oil or grease. Only petroleum distillates should be used to clean electrical components. Recommended are safety

type petroleum solvents having a flash point greater than

100’ F. (38* C.).

Use a soft brush or cloth to apply the solvent. Use care

to avoid damaging magnet wire or winding Insulation. After cleaning, dry all components thoroughly with mois ture-free, low pressure compressed air.

DANGER!

DO NOT WORK WITH SOLVENTS IN ANY EN CLOSED AREA. ALWAYS PROVIDE ADEQUATE VENTILATION. FIRE, EXPLOSION OR OTHER HEALTH HAZARDS MAY EXIST UNLESS ADE QUATE VENTILATION IS PROVIDED. WEAR EYE PROTECTION. WEAR RUBBER GLOVES TO PRO TECT THE HANDS.

CAUTIONI

Some generators use epoxy or polyester base winding varnishes. Use solvents that do not at tack such materials.

Page 1.4-2

Section 1.4- INSULATION RESISTANCE

Drying the Generator

GENERAL:

If testing Indicates that the insulation resistance of a winding Is below a safe value, the winding should be dried before operating the unit Some recommended drying methods include (a) heating units and (b) forced air.

HEATING UNITS:

If drying Is needed, the generator can be enclosed In

a covering. Heating units can then be Installed to raise the temperature about 15’-18* F. (8*-10* C.) above ambi ent.

FORCED AIR:

Portable forced air heaters can be used to dry the

generator. Direct the heated air Into the generator’s air

intake openings. Run the unit at no-load. Air temperature

at the point of entry Into the generator should not exceed

150* F. (66* C.).

Section 1.4- INSULATION RESISTANCE

Page 1.4-4

Section 1.5- COMPONENTS TESTING

Introduction

Problems that occur In the computer-controlled

RV generator generally Involve the following sys

tems or components:

1. The engine.

2. The Speed Control System.

3. The AC Generator.

4. The Genistor.

5. Battery Charge Circuit. 6{ CCG Circuit Board.

7. Wiring Harness and Front Panel.

This Section will discuss test procedures for the

following components. Also see Part 8 of this

Manual, “TROUBLESHOOTING".

1. The AC Generator (Stator).

2. The Genistor.

3. Battery Charge Circuit.

4. CCG Circuit Board.

Stator Assembly

GENERAL:

For additional information on the Stator, refer to

the following:

1. “ Stator Assembly“ on Page 1.2-2.

2. Section 1.4, “INSULATION RESISTANCE“.

SYMPTOMS OF STATOR FAILURE:

A. If the engine starts but the Stepper Motor does

not move, and shutdown occurs after several sec

onds, look for the following:

1. Broken or shorted Power Supply winding

(Wires PS1 and PS2).

2. Broken or shorted Timing winding (Wires TIM1 and TIM2).

NOTE: If the Power Supply windina Is shorted to

ground, a burned area on the CCG circuit board

mircult board ground track) may be visible. If the

Timing winding Is shorted to ground, the circuit will

probably be damaged but bum-up may not be vls-

A short circuit between windings.

□

NOTE: The resistance of Stator windings Is very

low. Some meters will not read such alow resis

tance and will simply Indicate “continuity". Recom

mended Is a high quality, digital type meter capable

of reading very low resistances.

TESTING POWER PHASE WINDINGS: A. Refer to Figures 1 and 2. To test the Power

Phase windings for an open circuit condition, pro ceed as follows:

1. Disconnect the following wires:

a. Lead “AC1" (Gray) at the Genistor. b. Lead “AC2” (Yellow) at the Genistor. c. Lead “SL1" (Orange) at the Genistor. d. Lead “SL2" (Brown) at the Genistor. e. Lead No. 11 (Blue) at the Main Circuit Breaker

(CB1).

2. Make sure all of the disconnected leads are isolated from each other and are not touching the

frame during the test.

3. Set a VOM to its "Rxl" scale and zero the

meter.

4. Connect one VOM test lead to Lead No. 11

. Then, connect the remaining test lead as

a. To Lead AC1 and note the resistance reading, b. To Lead AC2 and note the resistance reading, c. To lead SL1 and note the resistance reading, d. To lead SL2 and note the resistance reading.

NOMINAL RESISTANCE- POWER PHASE WINDINGS

Figure 1. Schematic- Stator Windings

POWER PHASE 1

POWER PHASE 2

0.30 to 0.42 ohm

B. If the engine shuts down but speed did NOT exceed 4500 rpm, look for the following:

1. One of the main windings (Power Phase 1 or

2) is open.

2. One of the main windings (Power Phase 1 or

2) is shorted to ground.

TESTING THE STATOR WITH A VOM:

A Volt-Ohm-Milliammeter (VOM) can be used to

test the Stator windings for tne following faults:

□ An open circuit condition. □ A "short-to-ground“ condition.

BATTERY CHARGE

nSGfiSIPr

PS1

POWER SUPPLY

TIMING

TIMI T1M2

Page 1.5-1

Section 1.5- COMPONENTS TESTING

Stator Assembly (Continued)

TESTING POWER PHASE WINDINGS

B. To test the Power Phase windings for a "short-toground* condition, proceed as follows:

1. Make sure all leads are Isolated from each other and

are not touching the frame.

2. Set a VOM to its *Rx10,000" or "RxlK* scale and zero the meter.

3. Connect one VOM test lead to the terminal end of Lead" AC1", the other test lead to a clean frame ground on the Stator.

a. The meter should read "infinity". b. Any reading other than "infinity" indicates a

"short-to-ground* condition.

TESTING POWER SUPPLY WINDINGS:

A. To test the Power Supply winding for an open circuit condition, proceed as follows:

1. Disconnect the 4-pin connector from "CONN4" of the CCG circuit board. See Rgure 3.

a. Stator lead "PS1* (Brown) connects to Pin 1 of

the connector.

b. Stator lead "PS2* (Yellow) connects to Pin 3 of

the connector.

2. Set a VOM to its *Rx1* scale and zero the meter.

3. Connect one VOM test lead to Pin 1 (Lead PS1Brown), the othet test lead to Pin 3 (Lead PS2-Yellow). The meter should indicate the resistance of the Power Supply winding.

NGS (CONT’D): NOTE: Any reading other than "Infinity'' Indicates

the winding Is shorted to ground. If winding Is open or shorted, the Stator should be replaced.

TESTING THE TIMING WINDING:

A. To test the Stator Timing winding for an open circuit condition, proceed as follows:

1. Disconnect the 4-pin connector from "CONN4" of

the CCG circuit board. See Rgure 3.

a. Stator lead TIM1 (Orange) connects to Pin 2 of the 4-pin connector.

b. Stator lead TIM2 (Gray) connects to Pin 4 of the 4-pin connector.

2. Set a VOM to its *Rx1 * scale and zero the meter.

3. Connect one VOM test lead to Pin 2 (Lead TIM1Orang^; connect the other test lead to Pin 4 (Lead

TIM2- Gray). The meter should Indicate the Stator Timing winding resistance.

B. To test the Timing winding for a "short-to-ground" condition, proceed as follows:

1. Set the VOM to its "Rx10,000* or "Rx1K" scale and

zero the meter.

2. Connect one VOM test lead to Pin 2 of the 4-pin

connector (Lead TIMI-Orange).

3. Connect the other test lead to a clean frame ground on the Stator. The meter should read "Infinity". Any reading other than "Infinity" Indicates the Timing winding is shorted to ground.

Figures. "CONN4“4-Pin Connector

NOMINAL RESISTANCE

STATOR TIMING WINDING

0.35-0.44 ohm

NOMINAL RESISTANCE

POWER SUPPLY WINDING

0.35-0.44 ohm

B. To test the Power Supply winding for a “short-toground" condition, proceed as follows:

1. Set the VOM to its “Rx10,000" or "RxlK" scale and

zero the meter.

2. Connect one VOM test lead to Pin 1 (Lead PS1Brown). Connect the other test lead to a clean frame ground on the Stator. The meter should read "infinity".

Page 1.5-2

SHORT CIRCUIT BETWEEN WINDINGS:

To test for a short circuit between windings, proceed

as follows:

1. Set a VOM to its "Rx10,000" or "RxlK" scale and zero the meter.

2. Connect one meter test lead to Stator lead PS1 (Brown).

3. Connect the remaining test lead to Stator lead AC1 (Gray). The meter should read "Infinity*. Any reading other than "infinity" indicates a shorted condition and the Stator should be replaced.

Section 1.5- COMPONENTS TESTING

4. Connect one VOM test lead to Stator lead AC1, the other test lead to Stator lead 77. The VOM should read "Infinity“.

5. Connect one VOM test lead to Stator lead AC1, the other test lead to Stator lead TIM1. The meter should read “Infinity”.

6. Connect one test lead to Stator lead PS1, the other to Stator lead TIM1. “Infinity" should be Indicated.

7. Connect one test lead to Stator lead PS1, the other to Stator lead 77. The VOM should read "Infinity".

8. Connect one VOM test lead to Stator lead TIMI, the other test lead to Stator lead 77. “Infinity" should be Indicated.

Genistor

GENERAL:

The “Genistor" or "Triac Module" is the FRE

QUENCY CONVERTER for the generator. For addi tional Information on the Genistor, refer to "The

Genistor" on Pages 1.2-3 and 1.2-4.

SYMPTOMS OF GENISTOR FAILURE:

If the engine shuts down but speed did not ex

ceed 4500 rpm, the following problems may exist:

1. Loss of the "Gate" connection (G1 through G4) between the CCG circuit board and the Genistor.

2. Although the correct “Gate" signal Is received from the CCG board, one or more switches are not gating.

3. The Genistor is not gating properly, I.e., one or more switches are permanently turned on.

4. Open circuit or loss of connection(s) between Stator and Genistor (Leads AC1, aC2, SLI, SL2,

22).

5. Open circuit or loss of connection between Genistor and CCG circuit board (Leads AC1, AC2, SL1,SL2).

TESTING THE GENISTOR:

Disconnect ail wires from the Genistor before

attempting to test it.

RESISTANCE READING "COM" to G1 s 20-60 Ohms "COM" to G2 > 20-60 Ohms "COM" to G3 o 20-60 Ohms "COM" to G4 B 20-60 Ohms

3. Set the VOM to its “Rx1” scale and zero the meter. Then connect the VOM test leads across

the “COM" terminal and the center screw. The VOM should read “continuity”.

4. Now, connect the VOM test leads across the fol lowing terminals and screws:

a. Across AC1 screw to AC1 terminal should read “continuity”.

b. Across AC2 screw to AC2 terminal should read “continuity”.

c. Across SLI screw to SLI terminal should read “continuity”.

d. Across SL2 screw to SL2 terminal should read “continuity”.

5. Set the VOM to its “Rxl 0,000” or “RxlK” scale

and zero the meter. Then, connect the VOM test

leads across each of the screws. There should be

no continuity between any of the screws (“infini

ty”).

NOTE: The resistance reading between any two of the screws on the Genistor is in the neighborhood of about 1 megohm (about 1 million amps). If the Genistor failed any of the proceeding tests, it

should be replaced.

f^lgure 4. Genistor Test Points

CAUTIONI

DO NOT attempt to test the Genistor until ALL leads have been disconnected. The genistor MUST be completely disconnected from the cir

cuit If testing is accomplished with any leads connected, alftest results are Invalid.

See Figure 4. To test the Genistor, proceed as

follows:

1. Set a VOM to a resistance scale that will allow a range of about 20-60 ohms to be read. Zero the meter.

2. Connect one VOM test leads to the "COM" termi nal and the other test lead to Terminals G1, G2, G3 and G4 one at a time. Read the resistance as the meter is connected to G1, to G2, to G3, and to G4.

Testing the Battery Charge Circuit

GENERAL:

The Stator Is equipped with

dual battery charge windings.

These windings deliver an AC output to a Battery Charge Rec tifier (BCR) which rectifies it

changes It to direct current or

C). The direct current Is deliv

ered to the unit battery, to main tain the battery in a charged state while the unit Is running.

figure 5,

BATTERY CHARGE

WINDING

Page 1.5-3

BCR

Section 1.5- COMPONENTS TESTING

Testing the Battery Charge Circuit

(Continued)

SYMPTOMS OF CIRCUIT FAILURE:

It is difficult to determine if the battery charm

circuit is operating without testing for correct volt age. If you suspect the battwery charge circuit Is defective, the following symptoms will usually point to a cause of the problem. See Figure 6.

1. If no AC voltage can be measured across Stator connections at the Battery Charge Rectifier (BCR), an open circuit condition probably exists in Wire 66 (Brown), or Wire 77 (Brown).

2. If AC voltage is available to the Wire 66 and 77 terminals at the battery Charge Rectifier, but no voltage or a low voltage Is measured between the

BCR’s Wire 55 terminal and ground, the Battery

Charge Rectifier (BCR) Is defective.

TESTING THE BATTERY CHARGE CIRCUIT: Test the Battery Charge winding as follows:

1. Disconnect Wire 77 at the Battery Charge Recti

fier (BCR).

2. Disconnect Stator output Wire 66 at the Battery Charge Rectifier (BCR).

3. Disconnect Wire 55.

4. Set a VOM to its ”Rx1" scale and zero the meter.

5. Connect the VOM test leads across Wires 77 and 55, then across Wires 66 and 55. Note the resis tance reading in both cases. Replace Stator As sembly, If defective.

BATTERY CHARGE WINDING RESISTANCE

ACROSS WIRES 66 TO 55 s 0.037-0.042 Ohm ACROSS WIRES 77 TO 55 s 0.037-0.042 Ohm

6. Use a VOM to measure AC voltage at the Wires 66 and 77 terminals of the Battery Charge

Rectifier, with the unit running. If no AC voltage is

measured, an open circuit exists in the wire 66 or

77 circuit.

7. With engine running, use a VOM to check for DC

voltage between the Battery Charge Rectifiers Wire 55 and frame ground. If AC voltage was pre

sent in step 6, but DC voltage is NOT present in

this stem, the Battery Charge Rectifier (BCR) is

d6f6CtiVG.

Testing the CCG Circuit Board

GENERAL:

It is difficult if not impossible to test the CCG circuit board in the field. Generally, if the other components in the AC generator system have

tested good, you may assume that any problem is

In the CCG circuit board.

NOTE: Also refer to “CCG Circuit Board" on Pages

Ï.2-4, 1^-5, and 1^-6.

SYMPTOMS OF CIRCUIT BOARD FAILURE:

1. If the engine starts, but the Stepper Motor does not move, and engine shuts down after several

seconds, the CCG circuit board’s micro-controiler may not be operating.

2. A failure of the circuit board’s Stepper Motor drive can result in the following:

a. Engine starts, but Stepper Motor does not

move. The engine accelerates uncontrollably

and shuts down when engine speed exceeds 4500 rpm.

b. Engine starts, but Stepper Motor does not move. The following symptoms occur:

(1) Engine appears to operate too slowly. (2) Engine is not able to handle the load and unit

operates at low AC output voltage. (3) After several seconds under load, AC output

voltage is turned off (overload condition).

3. If the engine can be started, but shuts down after several seconds, a timing detection faiiure may have occured (Timing winding. Wires TIM1, T1M2).

4. if the engine speed and output voltage are erratic under constant load, but the AC output does not turn off intermittently, erratic timing detection may have occured (Timing winding. Wires TIM1, TIM2).

NOTE: Timing detection Involves the circuit board’s ability to detect "zero crosslrws" of the sine wave (see “Alternating Current", Pages 1.1-1 and 1.1-2). The CCG clrculfboard must detect both

zero VOLTAGE and zero CURRENT crossings If the

system Is to operate properly. This “zero crossing“ detector Is used to synchronize an Internal clock on the circuit board. The frequency of the Input

waveform la measured by the circuit board and checked against a "reference“ frequency. The board then calculates a frequency divisor. By counting “zero voltage crossings“, an Internal reterence output polarity Is generated. The Genistor switch with the maximum potential In the direction of the Internal reference Is gated.

Page 1.5-4

Section 1.5- COMPONENTS TESTING

TESTING THE CIRCUIT BOARD;

There Is no practical way of testing the CCG

circuit board In the field. Read "SYMPTOMS OF CIRCUIT BOARD FAILURE" carefully. Test the Sta tor, the Genistor, and the Battery Charge circuit as outlined In this Section. Also perform a resistance test of the Stepper Motor (see Part 7, "THE VARI ABLE SPEED SYSTEM") and observe Its operation

If possible.

Inspect wiring and wiring connections between

the CCG circuit board and the Genistor as follows (refer to appropriate wiring diagram):

1. Check wires G1 through G4 (and Wire 22) for proper connections at circuit board and at the

Genistor.

2. Use a VOM to check Wires G1 through G4 (and Wire 22) for continuity.

3. Check Wires AC1, AC2, SL1 and SL2 (between circuit board and Genistor) for proper connections.

4. Use a VOM to check Wires AC1, AC2, SL1, SL2 (between circuit board and Genistor) for condlnu-

Ity.

If all tests are completed and no problem Is found

on other components of the system, replace the

CCG circuit board and check unit operation.

Page 1.5-5

Section 1.5- COMPONENTS TESTING

Page 1.5-6

Section 1.6- CONTROL PANEL

Construction

The panel Is constructed of sheet metal and Includes a panel box, a panel back cover and a front control panel. The panel box Is retained to an enolne-generator divider plate by five MS screws. Removal of these screws will permit the panel to be removed from the divider plate and set out of the way with connecting wires still attached. This will allow access to components housed In the control panel.

Figurer 1. Exploded View of Control Panel

Components

A heat sink bracket Is attached to the engine-generator

divider plate, for attachment of a heat sink to which a CCG circuit board and Genistor are mounted. See Items 26,31,32 and 38 In the Exploded View of Control Panel. Other components are also shown In the Exploded View.

Many of tnese components are part of the "ENGINE ELECTRICAL SYSTEM" (Part 6 of this manual).

ITEM

3 4

5 6 7

13 8

14 15 16

17 18 20 21 22 23 24 25

QTY

6 1

2 5

8 1 1 1 1

2 M6 Hex Nut

M5 Pan Head Machine Screw

Engine Controller Circuit Board

DESCRIPTION

Back Panel Cover

Control Panel Box

No. 10-32 Pan Head Screw

M4 Pan Head Screw

M5 Screw Snap Bushing 90’ Connector

25 amp circuit breaker

M6 Lockwasher Ignition Module 38 M5 Lockwasher

M4 Hex Nut

Ignition Coll Assembly

Ignition Coll Spacer

No. 8 Flatwasher 44 1 Ground Wire

Front Control Panel 45 1

Snap Bushing 46

Start-Stop Switch

Fuel Primer Switch

15 amp Fuse

Fuse Holder

ITEM

26 1 27 1 28 9

29 2

31 1 32 1 CCG Printed Circuit Board 33 4 M3 Pan Head Screw 34 4 M3 Lockwasher 35

36 1 500 ohm Power Resistor

37 4 M6 Screw 39 4

40 2

41 1 Terminal Block 42 43 1 Genistor Harness

47 48 2 Wiring Harness Clamp

49 1 Panel Harness (Not Shown)

QTY

1 1 ohm Power Resistor

1 Heat Sink Bracket

1 12-pln Connector

1 Remote Panel Harness 1

DESCRIPTION

Heat Sink

Battery Charge Rectifier

M4 Lockwasher

No. 10-32 Hex Nut

Genistor

M4 Pan Head Screw

M5 Hex Nut

Customer Wiring Harness

Snap Bushing

Page 1.6-1

Section 1.6- CONTROL PANEL

Page 1.6-2

Section 1.7- SHEET METAL

See ‘Exploded View of Sheet Metal" on next page. A

General

DIVIDER PLATE (Item 1 )separate8 the AC generator com ponents from the engine. The engine Itself Is enclosed by a BASE HOUSING WRAPPER (ftem 4), a FRAME (Item

24), and a BELLY PAN (Item 23). These components are sealed by means of rubber SEALS (Items 3), to prevent the escape of gases.

NP-30/NP-40 Generator

CONTROL PANEL BOX

DIVIDER PLATE

The LOWER FAN attaches to the engine shaft and Is

enclosed In a LOWER FAN HOUSING (Item 19). Air Is

drawn Into the enclosed area around the engine and

forced out of the LOWER FAN HOUSING.

Removal of sheet metal will be necessary for many

repairs and for replacement of most parts.

ROCKER COVER

COVER

OIL FILTER buy il

AIR CLEANER

I ...r

OIL FILL TAG

ionoanjiiJ

Page 1.7-1

Section 1.7- SHEET METAL

Parts List for Exploded View of Sheet Metal

ITEM 1 1

2 3 4 5 26 6 7 8 9 5 10 12 1 13 14 1 3/8"-16 Capscrew 38 1 Snap Bushing 15 16 17 18 19 20 21 1 22 1

24 25

QTY

Engine-Generator Divider Plate 1 Engine Upper Wrapper 1 Rubber Seal

2 Customer Mounting Ralls 4 M8 Lockwasher 32 1 Starter Contactor Insulator Boot 4

7 M6 Lockwasher 35 4 1 1 3/8” Lockwasher 39

1 3/8” Hex NHut 40 1 Air Outlet Deflector 41 1 1 Exhaust Muffler 1 1 45 1 Grounding Strap

1 Belly Pan 49 1 Muffler Lower Insulation 1 1

DESCRIPTION ITEM QTY DESCRIPTION

Grounding Strap

1/4” Lockwasher

Seal Retainer

M8 Flatwasher

No. 8 Hex Nut

M6-1.00 Capscrew

Lockwasher

Muffler Heat Shield

Base Housing Wrapper

M5 Screw 30

M8-1.25 Capscrew M8-1.25 Capscrew

Spark Arrestor Exhaust Clamp

Lower Fan Housing

Carburetor Baffle SKlrt

Rocker Cover Cover

Spark Plug Side Skirt 48

Frame

Grounding Strap

26 1 27 1 Fuel Pump 28 2 Barbed 90* Fitting 29

31 33 1 Oil Filter Opening Seal

34 1 36 1 Fuel Line

42 44

50 1 Muffler Upper Insulation

3 1/4”-20 Hex Nut 3 1 Starter Contactor

2 Hose Clamp 7 Lockwasher

1 No. 8 Hex Nut 2

1 1

1 Muffler Hanger Bracket

Page 1.7-2

Section 1.7- SHEET METAL

Exploded View of Sheet Metal

g 53 s ■«

Page 1.7-3

Section 1.7- SHEET METAL

Page 1.7-4

SECTION

TITLE

Part 2

ENGINE

MECHANICAL

COMPUTER

CONTROLLED

VARIABLE

SPEED RV

GENERATORS

Series NP-30G and NP-40G

2.1

2.2

2.3

2.4

GENERAL INFORMATION

VALVE TRAIN

PISTON, RINGS, CONNECTING ROD

CRANKSHAFT & CAMSHAFT

Section 2.1- GENERAL INFORMATION

Introduction

The engine used on Series NP-30G and NP-40G recre

ational vehicle AC generators Is a Generac Series GN190 or GN220, vertical shaft, single cylinder, overhead valve type.

These engines are not equipped with a mechanical engine governor. Instead, variable engine speeds are controlled by a computer circuit board. The circuit board signals a stepper motor to move the carburetor throttle linkage.

4-Cycle Engine Theory

GENERAL;

Series GN190 and GN220 engines require four (4) strokes or cycles to complete one power cycle. This is often called the ''4-stroke, 5-event" cycle. The 4 strokes and 5 events that occur are (1) Intake, (2) compression, (3) Ignition, (4) power and (5) exhaust

INTAKE STROKE (Figure 1):

The Intake valve is open. The exhaust valve Is closed. The piston travels downward, creating a suction which draws the air-fuel mixture from the carburetor Into the cylinder and Just above the piston.

COMPRESSION STROKE (Figure 2):

As the piston reaches bottom dead center (BOC), the

Intake valve closes. The exhaust valve remains closed, as well. The piston starts to move outward in the cylinder. Since both valves are closed, the air-fuel mixture In the cylinder Is compressed.

POWER STROKE (Figure 3);

Both valves remain closed. At some point before the piston reached top dead center (TDC), the spark plug fires to ignite the fuel-air mixture. The piston moves to its top dead center position and the burning, expanding gases of combustion force the piston downward.

EXHAUST STROKE (Figure 4):

The expanding gases of combustion force the piston

downward to its bottom dead center (BOC) position. The exhaust valve then opens, as the piston starts its move ment toward top dead center (TDC). Piston movement then forces the exhaust gases out through the open exhaust valve. The 4-stroke cycle of events then starts over again.

TIMING;

Valve timing and Ignition timing must be precisely

controlled If the engine Is to operate properly and effi ciently. Intake and exhaust valves must open and close In a precise timed sequence If the four strokes are to occur. Ignition must occur at exactly the correct piston position, just prior to the start of the power stroke.

Timing of valve opening and closing, as well as of spark

occurence. Is given in relation to the piston position and

the degrees of crankshaft rotation.

Ignition Is timed to occur several degrees before top dead center (TDC) of the piston, to allow time for the air-fuel mixture to ignite and start to bum before the

piston reaches top dead center

There must be no leakage past the valves in their closed position or compression will not develop. Like wise, there must be no leakage past the piston-

Figure 3. Power Stroke

Section 2.1- GENERAL INFORMATION

Recommended Fuels

GASOLINE FUEL SYSTEMS:

For models equipped with a gasoline fuel system, the

use of clean, fresh, UNLEADED, regular grade gasoline Is recommended. Unleaded gasoline burns cleaner, ex

tends engine life, and promotes better starting by reduc

ing carbon deposits In the combustion chamber.

Leaded "Regular* grade gasoline may be used if un

leaded gasoline Is not available.

The use of gasohol is NOT recommended. If it must be

used, it should not contain more than 10 percent ethanol.

When gasoline containing ethanol is used, special care

Is required when preparing the unit for storage (see "Storage Instructions").

DO NOT USE GASOLINE CONTAINING METHANOL. DO NOT MIX OIL WfTH THE GASOLINE.

DANGERl

GASOLINE IS EXTREMELY FLAMMABLE AND ITS VAPORS ARE EXPLOSIVE. DO NOT PERMIT SMOKING, OPEN FLAME, SPARKS OR ANY SOURCE OF HEAT IN THE VICINITY WHILE HAN DLING GASOLINE. AVOID SPILLAGE OF GASO LINE ON A HOT ENGINE. THERE MUST BE NO LEAKAGE OF GASOLINE INTO THE RV GENER ATOR COMPARTMENT.

GASEOUS FUEL SYSTEMS:

Some RV generator models may be equipped with an LP or natural gas fuel system. The use of such gaseous fuels may result in a slight power loss as compared to gasoline. However, that disadvantage is usually com pensated for by the many advantages offered by such fuels. Some of these advantages are:

Recommended Engine Oil

Use a clean, high quality, detergent oil that Is classified "For Service SC, SD, SE, SF or SG". Use no special additives with the oil.

G During summer months (above 32* F. or 0* C.), use

SAE 30 oil. SAE 10W-30 oil Is an acceptable substi tute.

G During winter months (below 32* F. or 0* C.), use SAE

5W-20 or 5W-30 oil.

G DONOTUSESAE10W-40OIL.

Engine crankcase oil capacity without oil filter change

is about 29 fluid ounces (850ml).

Engine crankcase oil capacity (with oil filter change)

is about 1 U.S. quart (946ml).

Change engine oil and the oil filter after the first eight

(8) hours of operation. Thereafter, change engine oil and oil filter every 50 operating hours.

NOTE: Additional Information on the engine oil system can be found In Part 5 of this manual,

"Engine Oil and Cooling System".

Storage Instructions

PREPARATION FOR STORAGE:

The engine should be started at least once every seven (7) days and allowed to run for at least thirty (30) minutes. If this cannot be done and the engine is to remain unused longer than thirty (30) days. It must be prepared for storage. To prepare the unit for storage, proceed as follows:

1. Start the engine and let It warm up.

2. After engine Is thoroughly warmed up, shut It down.

D A low residue content which results In minimum

carbon formation In the engine, n Reduced sludge buildup in the engine oil. n Reduced burning of valves as compared to gasoline.

D No "washdown" of the engine cylinder wall during

cranking and startup.

D Excellent anti-knock qualities,

n A nearly homogenous mixture in the engine cylin

der. □ Fuel can be stored for long periods without break

down.

DANGERl

GASEOUS FUELS ARE HIGHLY VOLATILE AND THEIR VAPORS ARE EXPLOSIVE. LP GAS IS

HEAVIER THAN AIR AND WILL SETTLE IN LOW AREAS. NATURAL GAS IS LIGHTER THAN AIR AND WILL ACCUMULATE IN HIGH AREAS. EVEN THE SLIGHTEST SPARK CAN IGNITE THESE

FUELS AND CAUSE AN EXPLOSION. THE USE

OF LEAK DETECTORS IS RECOMMENDED WHEN GASEOUS FUELS ARE USED. ALL CODES, STANDARDS AND REGULATIONS PER TAINING TO THE INSTALLATION AND USE OF GASEOUS FUELS MUST BE COMPLIED WITH.

NOTE: If the unit Is equipped with a gasoline fuel system and GASOHOL was used as a fuel, turn off

the supply of fuel to the engine and let It run out of

gas.

3. While engine Is still warm from running, completely drain the oil. Then, refill with the recommended oil. See "Recommended Engine Oil".

4. Attach a tag to the engine Indicating the viscosity and

classification of the oil m the crankcase.

5. Remove the spark plug and pour about one (1) ounce (15ml) of clean, fresh engine oil into the spark plug

threaded opening. Crank the engine several times to

distribute the oil, then Install and tighten the spark plug.

6. Remove the battery and store It In a cool, dry room on a wooden board. Never store the battery on any concrete

or wood floor.

7. Clean and wipe the generator exterior surfaces. RETURN TO SERVICE AFTER STORAGE:

To return the unit to service after storage, proceed as

follows:

1. Verify that the correct oil is In the engine crankcase by

checking the tag on the engine (see "Recommended

Engine Oil".) If necessary, drain oil and refill with the recommended oil.

Page 2.1-2

Section 2.1- GENERAL INFORMATION

2. Check the battery. Fill all battery cells to the proper level with distilled water. DO NOT USE TAP WATER IN

THE BATTERY. If necessary, recharge the battery to a

100 percent state of charge or replace It, If defective.

3. Turn OFF all electrical loads. Start the engine at no-

load and let It warm up.

4. Apply electrical looads to at least 50% of the unit’s rated capacity.

5. When engine Is thoroughly warmed up, turn off or disconnect all electrical loads. Then, shut the engine down.

THE UNIT IS NOW READY FOR SERVICE.

Engine Tuneup

The following procedure may be used as a minor

tuneup. On completion of the procedure, the engine

should run properly. If It does not run properly, additional checks and repairs are required.

1. Service and repair engine air cleaners, as necessary.

2. Check engine oil level and condition of oil. Add or change oil as required.

3. Remove shrouding and clean away dirt from the en gine cylinder head and cooling fins.

4. Check fuel filters and clean or replace as necessary.

5. Replace the spark plug with a Champion RC12YC (or equivalent) plug.

a. Set spark plug gap to 0.030 Inch (0.76mm). b. Install new plug and tighten to 13 foot-pounds (1.8

N-m). c. If a torque wrench Is not available, tighten spark

plug as tight as possible with fingers and then

(1) If plug is RE-USED, tighten about 1/4 turn more with a wrench.

(2) If plug Is NEW, tighten it about 1/2 turn more with a wrench.

6. Check that wiring Is free of breaks, abrasions and are properly routed.

7. Check for spark as outlined in "Ignition“ section of Part 6 of this manual.

8. Run engine, adjust carburetor If necessary and check operation.

Page 2.1-3

Section 2.1- GENERAL INFORMATION

Exploded View of Engine Long Block

ITEM

QTY

DESCRIPTION ITEM

1 1 (jonneciihg Hd'd & 2 1 3 4 2 5 6 7 2 8 10 1 11 1 12 13 14 15 4 16 17 3 18 19

21 1 22 1 23 1 24 1 25 1 26 27

1 1

Crankshaft & Gear Assembly

1 Sleeve Bearing 2

1 4 1

Crank Case Flange Gasket

Oil Pressure Spring Retainer

Oil Pressure Relief valve Ball

M6 Screw & Lockwasher

Piston Pin 32

Piston Ring Set (STD)

1/4“ Pipe Plug

Breather Cover

Piston

Piston Pin Retainer

Oil Breather Separator

Crankcase Assembly 41

Crankshaft Oil Seal 43 2

Breather Baffle Cup 44

M6 Screw

Lockwasher

Dowel Sleeve

Camshaft Assembky

Cylinder Head Gasket

Oil Pressure Spring

Thread Forming Bolt 54

Oil Filter Adapter 28 6 M8-1.25 Capscrew 29 1 30

Oil Pressure Switch

Valve Spring Retainer

NOTE 1Item 36 Includes valve seats and guides.

QTY DESCRIPTION

vaive spring

1 Dowel Pin 33 1 34 36 1 37 1 38 39 2 40

42 1

2 Tappet

Inner Oil Pump Rotor Connecting Rod Bolt

Cylinder Head (see NOTE 1)

Exhaust Valve

Intake Valve

Push Rod

Oil Pickup Screen

Rocker Cover Gasket

Pivot Ball Stud

45 46

2 2 1

Rocker Arm

Rocker Arm Nut

Puch Rod Guide Plate 47 5 Head Bolt 48 1 Rocker Cover

51 1 52 1 53 2

55 1 56 2

58 1 59 1 60

2 Breather Gasket 2 Bolt

Outer OH Pump Rotor

Oil Sump Assembly

Valve Spring Wear Washer

Intake Valve Seal

Oil Temperature Switch

M3 Screw

M3 Lockwasher Spark Plug (see NOTE 2) Oil Filter Adapter Gasket

1/4" NPT Pipe Plug

NOTE 2:- Use a Champion RC12YC (or equivakent)

spark plug with gap set to 0.030 Inch (0.76mm).

-------

€-J

----------

V4——

-------

4—

Page 2.1-4

Section 2.2- VALVE TRAIN

Valve Train Components

Valve train components are listed below and shown In

Rgure 1, below.

ITEM

QTY

1 2 3 4 2 5 6 1 7 2 8 2 9 2 10 11

2 2 2

DESCRIPTION

Tappet

Push Rod

Rocker Arm

Pivot Ball Stud

Rocker Arm Jam Nut

Push Rod Guide Plate

Valve Spring

Valve Spring Retainer

Valve Spring Washer

Exhaust Valve

Intake Valve

2. Loosen the rocker arm Jam nuts on the pivot ball studs.

Then, loosen the pivot ball studs. Remove the two pivot

ball studs, the rocker arms and the Jam nuts. Also remove

the push rod guide plate.

NOTE: Keep the Intake valve and exhaust valve parts separated. Intake and exhaust parts are Iden tical. However, once a wear pattern has been estab lished on these parts their tit will be different.

3. Remove the push rods.

4. Remove the cylinder head bolts, then remove the

cylinder head and head gasket

Valve Components Removal

1. The ROCKER ARM COVER Is retained by four M6-1.00 X 12mm screws and lockwashers. Remove the four screws and lockwashers, then remove the ROCKER ARM COVER and Its gasket

NOTE: Replace the ROCKER ARM COVER GASKET each time the COVER Is removed, to ensure proper sealing.

NOTE: Replace the head gasket every time the head Is removed. The new head gasket must be free of nicks and scratches as these could cause leakage.

Figure 4. Cylinder Head Removal

CYLINDER

CYUNDER HEAD BOLTS

HEAD

HEAD GASKET

CRANKCASE

DANGERI

ALWAYS WEAR SAFETY GLASSES WHEN RE MOVING THE VALVE SPRINGS.

5. See Figure 5, next page. Hold the valve with your fingers while compressing the spring with your thumb, then proceed as follows:

Page 2.2-1

Section 2.2- VALVE TRAIN

Valve Components Removal (Con

tinued)

a. While the spring is compressed, slide the larger hole of the valve spring retainer toward the valve stem.

b. With the larger spring retainer hole around the valve stem, release the spring.

c. Remove the valve spring retainer, the spring and the spring washer.

6. Remove the Intake and exhaust valves.

7. Clean all parts. Remove carbon from valve heads and stems.

8. Inspect the valves and valve seats. Service parts as outlined under ‘Valve Service*.

DESIGN MARGIN: 0.034-0.044 Inch (0.87-1.13mm)

VALVE MARGIN (GN220)

WEAR LIMIT: 0.020 Inch (0.50mm) Maximum

INTAKE VALVE STEM DIAMETER (GN190)

DESIGN DIAMETER: 0.215-0.216 Inch (5.465-5.480mm)

WEAR LIMIT: 0.214 inch (5.435mm) Minimum

INTAKE VALVE STEM DIAMETER (GN220)

DESIGN DIAMETER: 0.274-0.275 inch (6.965-6.980mm)

WEAR LIMIT: 0.273 Inch (6.934mm) Minimum

EXHAUST VALVE STEM DIAMETER (GN190)

DESIGN DIAMETER: 0.214-0.215 inch (5.445-5.460mm)

WEAR LIMIT: 0.213 Inch (5.415mm) Minimum

EXHAUST VALVE STEM DIAMETER (GN220)

DESIGN DIAMETER: 0.273-0.274 Inch (6.945-6.960mm)

WEAR LIMIT: 0.272 Inch (6.909mm) Minimum

NOTE: Design sizes and wear limits of valve train components can also be found In Part 9 of this Manual (“SPECIFICATIONS & CHARTS").

VALVE SEATS:

Valve seats are NOT replaceable. If burned or pitted, seats can be reground. Grind seats

at a 45* angle and to a width of 0.039 Inch

(1.0mm).

Figure 7.

SEAT

^WIDTH

,\ V ’1

Valve Service

VALVES:

Replace valves if they are damaged, distorted or if the margin is ground to less than 0.039 Inch (1.0mm). If the valves are In useable condition,

use a valve grinder to grind the faces to a 45* angle. Check valve stem diameter.

After the valves have been reconditioned, they should be lapped with a suitable lapping tool and valve lapping com pound.

NOTE: Proper lapping of valves and valve seats will remove grinding marks and ensure a good seal between the valve and Its seat. Be sure to clean lapping compound from the valve seats and faces.

VALVE MARGIN (GN190)

DESIGN MARGIN: 0.058-0.060 inch (1.48-1.52mm)

WEAR LIMIT: 0.039 inch (0.98mm) Maximum

STEM —

45"

Figure 6.

FACE

--------f

MARGIN

VALVE SEAT WIDTH (GN190 & GN220)

DESIGN WIDTH: 0.034-0.044 inch (0.87-1.13mm)

WEAR LIMIT: 0.064 inch (1.63mm) Maximum

VALVE GUIDES:

Valve guides are permanently Installed in the cylinder

head and cannot be replaced. If the guides become worn beyond the wear limit, they can be reamed to accomod ate a 0.020 Inch (0.50mm) oversize valve stem. Use a straight shank hand reamer or a low speed drill press to ream valve guides.

VALVE GUIDES (GN190)

DESIGN DIAMETER: 0.216-0.217 Inch (5.505-5.520mm)

WEAR LIMIT: 0.218 inch (5.54mm) Maximum

VALVE GUIDES (GN220)

DESIGN DIAMETER: 0.237-0.2364 inch (6.02-6.005mm)

WEAR LIMIT: 0.238 inch (6.045mm) Maximum

NOTE: After the valve guides have been oversized, be sure to recut the valve seats so they will align

with the guides.

Page 2.2-2

Section 2.2- VALVE TRAIN

Valve Service (Continued)

VALVE TAPPETS!

Valve tappets can be

removed during re

moval of the engine camshaft. Intake and exhaust valve tappets are Identical. However, once a wear pattern

has been established

the two tappets should

not be Interchanged.

1. Lubricate the valve stems and the valve guides with engine oil.

2. Install the Intake and exhaust valves through their respective valve guides in the cylinder head.

a. The exhaust valve has the smaller head with a diameter of 1.053 Inches (26.75mm).

b. The Intake valve has the larger head, having a diameter of 1.171 Inches (29.75mm).

c. Valve seat sizes In the cylinder head will match their respective head sizes.

NOTE: The exhaust valve stem Is also smaller than

that of the Intake valve.

Figure 11. Installation of Intake and Exhaust Valves

VALVE SPRINGS:

Inspect the valve springs. Measure the spring free length. Also, cneck the amount of force required to compress the spring to a length of 1.39 Inch (35.2 mm). Replace any damaged or defective spring.

VALVE SPRING FREE LENGTH

GN190:1.910 Inch (48.48mm)

GN220: 2.074 Inch (52.69mm)

FORCE REQUIRED TO COMPRESS SPRING

TO 1.39 INCH (35.2MM)

GN190:14.8-16.2 lbs (6.7-7.4kg)

GN220:19.8-21.8 lbs (9.0-9.9kg)

Valve Components Installation

After the valve train parts have been Inspected and (If

necessary) serviced. Install them as follows:

BE SURE TO LUBRICATE VALVE

GUIDES A STEMSI

3. Install the valve spring washers, valve

springs and valve spring retainers over

the valve guides.

a. Hold the valve with your fingers and use your thumbs to com press the spring.

b. When the spring Is compressed suf ficiently, slide the spring retainer small opening over the valve stem.

c. With the smaller retainer opening around the valve stem, release the spring.

4. After both valves have been retained in the cylinder head, position a new head gasket and Install the cylinder head.

NOTE: The head gasket Is coated with a special substance for better sealing. The gasket must be

free of nicks, scratches and other defects for better

sealing.

5. Install cylinder head bolts. Tighten the head bolts In the sequence shown to the recommended tightness.

Page 2.2-3

Section 2.2- VALVE TRAIN

Valve Components Installation

(Continued)

TIGHTENING TORQUE

CYLINDER HEAD

GN190: 25 foot-pounds GN220: 29 foot-pounds

6. Place the push rod guide plate Into position on the head. Then, Install the rocker arm and the pivot ball stud. The rocker arm Jam nut must be on far enough to hold the guide plate In position.

NOTE: Do NOT adjust valve clearance at this time.

This will be done later.

Adjusting Valve Clearance

When adjusting valve clearance, the enolne should be

at room tenmerature and the piston shouldbe at top dead

center (TDC) of Its compression stroke (both valves closed).

VALVE CLEARANCE

GN190 ENGINE

INTAKE VALVE: 0.001-0.003 Inch (0.03-0.07mm)

EXHAUST VALVE: 0.001-0.003 Inch (0.03-0.07mm)

VALVE CLEARANCE

GN220 ENGINE

INTAKE VALVE: 0.001-0.0022 Inch (0.03-0.056mm)

EXHAUST VALVE: 0.0018-0.003 Inch (0.046-0.07mm)

7. Install the push rod with either end against the tappet a. Place the push rod between the guide plate tabs.

b. Place the rocker arm socket onto end of push rod.

c. Alignment Is correct when push rod ball rests In the

rocker arm socket.

NOTE: The pivot ball stud will be tightened when the valve clearance Is adjusted. After valve clear

ance has been adjusted, the rocker arm cover will be Installed.

Adjust the valve clearance as follows:

1. Rotate the crankshaft until the piston Is at top dead center (TDC) of Its compression stroke. Both valves should be closed.

2. Loosen the rocker arm Jam nut

3. Use an alien wrench to turn the pivot ball stud while checking the clearance between the rocker arm and the valve stem with a feeler gauge.

Page 2.2-4

Section 2.2- VALVE TRAIN

4. When valve clearance is correct, hold the pivot ball stud with the alien wrench while tightening the rocker arm |am nut with a crow’s foot. Tighten the Jam nut to the specified torque. After tightening the Jam nut, recheck the valve clearance to make sure It did not change.

JAM NUT TIGHTENING TORQUE

GN190: 75 Inch-pounds GN220: 6.3 foot-pounds

Rocker Arm Cover installation

Place a new rocker arm cover gasket into place. Then,

install the rocker arm cover. Finally, retain the cover with M6-1.00 X 12mm screws.

Page 2.2-5

Section 2.2- VALVE TRAIN

Page 2.2-6

_________

Section 2.3- PISTON, RINGS, CONNECTING ROD

Oversize Piston & Rings

Worn or scored cylinders may be rebored to 0.010

(OJZSmm) or 0.020 (0.50mm) oversize. Pistons and pis ton rings of matching oversize are available to fit the rebored cylinder.

Figure 1. Piston, Rings and Connecting Rod

CONNECTING ROD

-RINGS

SNAP"

RING

Prior to Removai

Before removing pistons, rings and connecting rod, clean all carbon from the cylinder bore. Carbon buildup In the cylinder bore can cause ring breakage during piston removal.

Removai

Remove the connecting rod CAP BOLTS and the con

necting rod CAP. Then, push the piston and connecting

rod out through top of cylinder.

CHECK FOR PISTON WEAR:

The piston is slightly elliptical. It’s smaller diam

eter is in line with the wrist pin boss. It’s larger diameter is 90° from the wrist pin boss.

NOTE: An assembly mark Is provided on the piston.

This mark should face the flywheel end of the

crankshaft (3:00 position) during reassembly.

Figure 3. Elliptical Shape of Piston

2.747-2.748 In.

69.789-69.809mm

2.753-2.754 In.

69.939-89-959tnm

To check the piston for wear, proceed as follows:

1. Minor Diameter:- At a posi

Figure 4.

tion directly in line with the wrist pin hole, measure from top of piston down to a dis tance of 1.4-1.6 Inches (35.5-

40.5mm). This is the "minor" diameter. Measure at this point to check for wear.

Piston

REMOVE FROM CONNECTING ROD;

NOTE: An oil hole In the wrist pin area of the piston helps distribute oil to assist In cooling. The oil hole also provides an assist In removing the wrist pin snap ring.

To remove the piston from the connecting rod, proceed

as follows:

1. Move the snap ring around until its protruding end is

aligned with the notched out oil hole. Use needle nose pli ers to turn the snap ring and

puil it toward you.

2. With one snap ring re

moved, slide the wrist pin out of the piston boss. This will separate the piston from the connecting rod.

PISTON MINOR DIAMETER (GN190 & GN220) DESIGN DIAMETER: 2.747-2.748 inch (69.789-

69.809mm)

WEAR LIMIT: 2.745 Inch (69.739mm) Minimum

2. Major Diameter:- At a point 90* from the wrist pin bore, measure down 1.4-1.6 inches

(35.5-40.5mm). This Is the

"major" diameter. Measure at

this point to check for piston wear. Replace the piston if wear

limits are exceeded.

3. Check wrist Pin for Looseness:- A rough check for

wear in the wrist pin, wrist pin bore in the piston, or wrist

pin bore In the connecting rod is to check for looseness or play with the piston assembled to the rod. Looseness or play Indicates a worn wrist pin, or a worn bore in the piston or connecting rod.

NOTE: Always apply engine oil to wrist pin and Its bores during Installation. Wrist pin fit Is very close.

Page 2.3-1

Section 2,3- PISTON, RINGS, CONNECTING ROD

Piston (Continued)

CHECK PISTON FOR WEAR (CONT’D):

4. Check Wrist Pin for Wear:- Measure the outside diam eter of the wrist pin. Also measure the inside diameter of the wrist pin bore in the piston and In the connecting rod. Also check wrist pin length. Replace any component that is worn excessively.

WRIST PIN OUTSIDE DIAMETER (GN190 & GN220)

DESIGN DIAMETER: 0.708-0.709 Inch (17.989-

18.000mm)

WEAR UMIT: 0.707 Inch (17.969mm) Minimum

WRIST PIN LENGTH (GN190 & GN220)

DESIGN LENGTH: 2.196-2.213 Inch (55.8-56.2mm)

WEAR LIMIT: 2.193 inch (55.7mm) Minimum

WRIST PIN BORE IN PISTON (GN190 & GN220)

DESIGN DIAMETER: 0.708-0.709 inch (18.000-

18.011mm)

WEAR LIMIT: 0.710 Inch (18.026mm) Maximum

CONNECTING ROD SMALL END I.D. (GN190 & GN220)

DESIGN DIAMETER: 0.709-0.710 inch (18.02-18.03mm)

WEAR UMIT: 0.711 inch (18.05mm) Maximum

5. Ring to Groove Side Clearance:- Clean carbon from

piston ring groov js. Install new rings. Use a feeler gauge to measure the side clearance between the rings and ring grooves. If ring-to-groove side clearance exceeds the stated limits, replace the piston.

Piston Rings

GENERAL:

The following rules pertaining to piston rings must

always be complied with:

□

Always replace piston rings in sets.

□

When removing rings, use a ring expander to pre vent breakage. Do not spread the rings too far or they will break.

D When installing the piston into the cylinder, use a

ring compressor. This will prevent ring brteakage

and/or cylinder damage.

n When installing new rings, deglaze the cylinder wall

with a commercially available deglazing tool.

RING DESCRIPTION:

A piston ring SET consists of (a) a top compression ring, (b) a second compression ring, and (c) an oil ring assembly. When installing rings, pay close attention to the following:

G The OIL RING is a 3-piece assembly which consists

of two oil rails and an oil spacer ring. Oil rails have a rounded face and can be Installed with either side

_ up-

□ The second compression ring has an inside chamfer

which must face UP when installing the ring.

G The top compression ring has a barrel-shaped face

and can be Installed with either side up.

Figure 7. Ring Locations in Piston Grooves

RING TO GROOVE SIDE CLEARANCE (GN190 &

GN220)

0.0004-0.0014 inch (0.012-0.034mm)

Figure 6. Ring to Groove Side Clearance

1ST COMPRESSION RING

TOP COMPRESSION RING EITHER SIDE UP

2ND COMPRESSION RING CHAMFER FACES UP

OIL CONTROL RING EITHER SIDE UP

CHECKING PISTON RING END GAP:

To check piston rings end gap, proceed as follows

(see Figure 8):

1. Locate a point inside the cylinder that Is 2.75 inches

(70mm) down from top of cylinder. This Is approximately

half-way down.

2. Place the ring into the cylinder. Use the piston to push the ring squarely into the cylinder to the proper depth.

3. Use a feeler gauge to measure the ring end gap. If end gap is excessive, rebore the cylinder to take oversize parts.

TOP RING END GAP (GN190 & GN220)

DESIGN GAP: 0.005-0.016 inch (0.15-0.40mm)

WEAR LIMIT: 0.024 inch (0.60mm) Maximum

Page 2.3-2

Section 2.3- PISTON, RINGS, CONNECTING ROD

SECOND RING END GAP )GN190 & GN220)

DESIGN GAP: 0.006-0.016 Inch (0.15-0.40mm)

WEAR LIMIT: 0.024 Inch (0.60mm) Maximum

OIL RING END GAP (GN190 & GN220)

DESIGN GAP: 0.015-0.055 Inch (0.38-1.40mm)

WEAR LIMIT: 0.062 Inch (1.60mm) Maximum

Connecting Rod

Tha connecting rod Is man

ufactured of die cast alumi num. Alignment marks are provided on the rod and on the connecting rod cap. Be sure to align these marks when as sembling the rod to the crank shaft. Connecting rod bolts are of the "washerless" type.

The connecting rod and the

connecting rod cap are a matched set and must be re placed as a matched set

INSTALLATION:

Coat the cylinder walls with engine oil, as well as the crank throw, connecting rod bearing and connecting rod cap bearing. Then, Install the rod and piston assembly as follows:

1. Use a ring compressor to compress the rings Into the piston ring grooves. MAKE SURE ALL RINGS ARE FULLY COMPRESSED INTO THEIR GROOVES.

2. Guide the connecting rod Into the cylinder, with as sembly mark on piston toward the flywheel side of en gine.

3. When the ring compressor contacts top of cylinder, use a wood hammer handle to gently tap the piston down into the cylinder.

4. Check that the connecting rod’s large diameter bear ing is coated with oil, as well as the crank throw and the connecting rod cap.

5. Guide the large end of the connecting rod onto the crankshaft Install the connecting rod cap. The match mark on the cap must be aligned with an Identical mark on the rod (Figure 10).

6. Install the corinecting rod cap bolts and tighten to the proper torque.

TIGHTENING TORQUE

CONNECTING ROD CAP BOLTS (GN190 & GN220)

10 foot-pounds (1.36 N-m)

NOTE: The connecting rod can be Installed In either direction. That Is, the cap marks on the rod and cap may face toward the Installer or away from the Installer. The only requirement Is that the assembly mark on top of piston be toward the flywheel side of engine.

Assembly and Installation

ASSEMBLY:

Use a ring expander when Installing rings Into the piston ring grooves. Install the OIL RING ASSEMBLY first. Then, Install the second compression ring with its Inside chamfer facing up. Finally, install the top com pression ring.

When assembling the piston, connecting rod and wrist pin, the assembly marks on the piston must be toward the flywheel side of the engine.

Coat the wrist pin, wrist pin bore In piston, and wrist pin bore in the rod with engine oil. Install one snap ring Into the piston’s wrist pin bore. Then, assemble the piston to the rod. Slide the wrist pin through one piston bore, through the rod bore, and through the second piston bore until It contacts the snap ring. Then, Install the second snap ring into the piston bore.

Cylinder Service

INSPECTION:

Check the cylinder for dirty, broken or cracked fins. Also look for worn or scored bearings, or a scored cylinder wall. Check the cylinder head mounting surface for warpage. If the head is warped, it must be replaced. If the cylinder bore Is worn (as evidenced by excessive

ring end gap), the cylinder should be replaced or rebored

to 0.010 or 0.020 (0.25 or 0.50mm) oversize.

After reboring the cylinder to a specific oversize, In

stall an Identically oversize piston along with identically

oversized rings.

Page 2.3-3

Section 2.3- PISTON, RINGS, CONNECTING ROD

Cylinder Service (Continued)

REBORING THE CYUNDER;

Always resize the cylinder bore to EXACTLY 0.010

Inch or 0.020 Inch (0.25 or 0.50mm) over the standard cylinder dimensions. If this Is done accurately, the ser vice oversize ring and piston will fit and correct clear ances will be maintained.

STANDARD CYUNDER BORE DIAMETER

MINIMUM: 2.7560 Inches (70.000mm)

MAXIMUM: 2.7570 Inches (70.025mm)

To rebore the cylinder, use a commercial hone of suitable size chucked In a drill press having a spindle speed of about 600 rpm. Use the stones andlubrlcatlon recommended by the hone manufacturer to produce the proper cylinder bore finish. Proceed as follows:

1. Start with coarse stones. Center the cylinder under the drill press spindle. Lower the hone so that the lowest end of the stone contacts the lowest point in the cylinder bore.

2. Begin honing at bottom of cylinder. Move the hone up or down at about 50 strokes per minute, to avoid cutting ridges In the cylinder wail. Every fourth or fifth stroke,

move the hone far enough to extend it one (1) Inch beyond the top and bottom of the cylinder bore.

3. Every 30 or 40 strokes, check the bore for size and

straightness. If stones collect metal, clean them with a wire brush.

4. Hone with coarse stones until the cylinder bore is

within 0.002 Inch (0.05mm) of the desired finish size. Then, replace the coarse stones with burnishing stones and continue until bore is within 0.0005 inch (0.01mm) of the desired size.

5. Install finishing stones and polish the cylinder to its

final size.

6. Clean the cylinder with soap and water. Dry thor

oughly.

7. Replace the piston and rings with parts of correct oversize.

Page 2.3-4

Section 2.4- CRANKSHAFT AND CAMSHAFT

General

Prior to removal of the crankcase cover, gain access

to the engine and generator by removing surrounding sheet metal as required. See Section 1.6.

Crankcase Cover Removal

Before attempting to remove the crankcase cover,

remove rust, paint and burrs from the power takeoff

end of the crankshaft. This will reduce the possl-

of damaging the oil seal In the crankcase cover or

the bearing during cover removal.

To remove the crankcase cover, proceed as follows:

1. Drain oil from the crankcase.

2. Remove the et^lne cylinder head, push rods and push rod guide plate. See Section 2.2.

3. Remove all bolts that retain the crankcase cover to the crankcase.

4. Remove the crankcase cover. If necessary, tap lightly with a soft hammer on alternate sides of the cover.

Camshaft Removal

See Figure 2. Remove the camshaft as follows:

1. Tip the engine over onto the flywheel end of the

crankshaft. Support the engine to prevent end of crank shaft from resting on the workbench.

2. Reach In with two fingers and hold the tappets up so they are clear of the camshaft lobes. Then, remove the camshaft.

3. Remove the two tappets.

4. Remove the outer and Inner oil pump rotors.

Crankshaft Removal

See Figure 3. To remove the crankshaft, proceed as

follows:

1. The engine flywheel must be removed before the crankshaft can be removed.

2. The piston and connecting rod must be removed.

3. Remove the crankshaft by pulling It straight out of the crankcase.

Camshaft Inspection

Carefully Inspect the entire camshaft for wear, nicks,

damage. All areas Indicated In Figure 4 should be checked for wear.

Section 2.4- CRANKSHAFT AND CAMSHAFT

Camshaft Inspection (Continued)

The following should be measured carefully to check

for wear:

MAIN CAMSHAFT BEARING DIAMETER

(FLYWHEEL END)

DESIGN DIAMETER: 1.022-1.023 Inch (25.96-25.98mm)

WEAR LIMIT: 1.020 Inch (25.91mm) Minimum

MAIN CAMSHAFT BEARING DIAMETER

(PTO END) GN-190 ONLY

DESIGN DIAMCTER: 1.022-1.023 Inch (25.96-25.98mm)

WEAR LIMIT: 1.020 Inch (25.91mm) Minimum

MAIN CAMSHAFT BEARING DIAMETER

(PTO END) GN-220 ONLY

DESIGN DIAMETER: 1.297-1.298 Inch (32.96-32.98mm)

WEAR LIMIT: 1.295 Inch (32.89mm) Minimum

CAMSHAFT BEARING BORE IN CRANKCASE

DESIGN DIAMETER: 1.024-1.025 Inch (26.00-26.03mm)

WEAR LIMIT: 1.026 Inch (26.06mm) Maximum

CAMSHAFT BEARING BORE IN CRANKCASE COVER

DESIGN DIAMETER: 1.299-1.300 inch (33.00-33.03mm)

WEAR LIMIT: 1.302 Inch (33.06mm) Maximum

DESIGN DIAMETER: 1.180-1.181 INCH (29.99-30.01 MM)

CRANKPIN OUTSIDE DIAMETER

WEAR LIMIT: 1.179 inch (29.96mm) Minimum

CRANKSHAFT BEARING JOURNAL (FLYWHEEL END)

DESIGN DIAMETER: 1.102-1.103 Inch (28.000-

28.012mm)

WEAR LIMIT: 1.100 inch (27.95mm) Minimum

CRANKSHAFT BEARING JOURNAL (PTO END)

DESIGN DIAMETER: 1.102-1.103 inch (28.000-

28.012mm)

WEAR LIMIT: 1.186 inch (27.95mm) Minimum

DESIGN LIFT: 0.210-0.212 Inch (5.34-5.38mm)

CAM LIFT

WEAR LIMIT: 0.206 Inch (5.24mm) Minimum

Crankshaft Inspection:

CRANKSHAFT PROPER:

Use a commercial solvent to clean the crankshaft.

After cleaning, Inspect the crankshaft as follows: □ Inspect keyways in crankshaft, make sure they are

not worn or spread. Remove burrs from edges of keyway, to prevent scratching the bearing.

D Inspect timing gear teeth for chipping or cracking. If

the timing gear Is damaged, the crankshaft assembly must be replaced.

G Inspect the crankpin for damage, nicks, scratches,

etc. Small nicks and scratches may be polished out using fine emery cloth. ALL EMERY RESIDUE MUST BE REMOVED. Use a solvent (such as kerosene) to remove emery residue.

D Carefully measure the outside diameter (O.D.) of the

crankpin, crankshaft journal at flywheel end, and crankshaft journal at PTO end. Replace the crank shaft if it is worn smaller than the stated limits.

NOTE: DO NOT regrInd the crankpin to any smaller diameter. Undersize connecting rods are NOT available for the GN-190 or GN-220 engines.

G Inspect oil passage. Use a length of wire to make

sure it Is open. Inspect threaded ends of crankshaft.

CRANKSHAFT SLEEVE BEARING:

A sleeve bearing (Figure 6) Is pressed into the crank

shaft bore of the crankcase. A bearing is NOT provided

for the crankshaft bore in the crankcase cover.

Inspect the sleeve bearing In the crankcase for dam

age. Measure the inside diameter (I.D.) of the sleeve bearing. Replace any sleeve bearing that Is worn exces sively. Press out the old bearing, press a new bearing into place.

CRANKSHAFT SLEEVE BEARING

DESIGN DIAMETER: 1.104-1.106 inch (28.044-

28.099mm)

WEAR LIMIT: 1.107 inch (28.129mm) Maximum

Check the crankshaft bearing bore in the crankcase

cover. If limits are exceeded, replace the crankcase

cover.

CRANKSHAFT BEARING BORE IN CRANKCASE

COVER

DESIGN DIAMETER: 1.104-1.105 inch (28.040-

28.065mm)

WEAR LIMIT: 1.106 inch (28.092mm) Maximum

Page 2.4-2

Section 2.4- CRANKSHAFT AND CAMSHAFT

Figure 9. Measuring Compression Release Lift

Compression relief lift can also

Compression Release Mechanism

A mechanical compression release Is provided on the

camshaft. See Rgure 8. A PIN extends over the cam lobe.

This PIN pushes on the tappet, to lift the valve and relieve

compression for easier cranking. When the engine starts, centrifugal force moves the FLYWEIGHT outward against SPRING force. The PIN will then drop back and allow the engine to run at full compression.

Measure the amount of compression release lift at the

tappet (Rgure 9).

COMPRESSION RELEASE LIFT FOR GN-190 ENGINE

(MEASURED AT TAPPET)

DESIGN LIFT: 0.027-0.055 Inch (0.70-1.40mm)

WEAR LIMIT: 0.023 Inch (0.60mm) Minimum

COMPRESSION RELEASE LIFT FOR GN-220 ENGINE

(MEASURED AT TAPPET)

DESIGN LIFT: 0.020-0.047 Inch (0.50-1.20mm)

WEAR LIMIT: 0.016 Inch (d.406mm) Minimum

Installing the Crankshaft

Before Installing the crankshaft, lubricate all bearing

surfaces with engine oil. Use oil seal protectors, to pre vent damage to seals during installation. Install the crankshaft as follows:

1. Lubricate all bearing surfaces with engine oil.

2. Install the valve tappets.

3. Support both ends of the crankshaft and carefully

Install Into the crankcase.

4. Rotate the crankshaft until the timing mark (Figure

10) is toward the cam gear side of the crankcase.

Installing the Camshaft

Apply engine oil to the camshaft main bearing and to

bearing bore In crankcase. Carefully install the camshaft Into the crankcase camshaft bore.

Hold the tappets out of the way during Installation. Align timing mark on camshaft gear with timing mark on crankshaft gear (piston will be at top dead center). See

Figure 11.

Page 2.4-3

Section 2.4- CRANKSHAFT AND CAMSHAFT

Installing the Camshaft (Continued)

NOTE: For Installation ot the oil pump assembly,

oil pickup assembly and crankcase cover, see Part

5 "ENGINE OIL & COOUNG SYSTEM".

Figure 10. Timing Mark on Crankshaft Gear

Page 2.4-4

Part 3

GASOLINE

FUEL

SYSTEM

COMPUTER

CONTROLLED

VARIABLE

SPEED RV

GENERATORS

Series NP-30G and NP-40G

SECTION

3.2

3.3

3.4

3.5

3.6

TITLE

im66U6TI(5NT(SPUEL5V§TgM

AIR CLEANER & AIR INTAKE

FILTER & FUEL PUMP

CARBURETOR

AUTOMATIC CHOKE

SPEED CONTROL SYSTEM

Section 3.1- INTRODUCTION TO FUEL SYSTEM

General

Recreational vehicle generators equipped with a gas

oline fuel system are usually Installed so that they share

the fuel supply tank with the vehicle engine. When this

Is done, the generator Installer must never tee off the

vehicle fuel supply line to deliver fuel to the generator.

When the generator fuel supply line Is teed off the

vehicle’s fuel supply line, the more powerful vehicle

engine’s fuel pump will starve the generator when both are running. In addition, when the vehicle engine Is not running the generator fuel pump will draw all of the gasoline from the vehicle engine line or even from the vehicle engine carburetor. This will result in hard starting of the vehicle engine.

One method of sharing the same fuel supply tank is to install a special fitting at the tank outlet so that two fuel dip tubes can be fitted In the tank (Rgure 1). Another method Is to Install a new outlet In the tank. If the tank has an unused outlet, it can be used.

A second fuel dip tube can be Installed In the original

tank outlet if the tank outlet Is large enough to accommo

date two dip tubes. The required fittings can be made at

a machine shop. To install a second fuel outlet on the tank means removing the tank to braze or weld a new

fitting Into place.

DANGER!

ATTEMPTING TO WELD OR BRAZE ON A FUEL TANK, EMPTY OR NOT, IS EXTREMELY DAN GEROUS. FUEL VAPORS IN THE TANK WILL RE SULT IN AN EXPLOSION.

The generator’s fuel dip tube in the tank should be shorter than the vehicle engine’s dip tube. This will prevent the generator from consuming the entire fuel supply.

DANGERI

THE FUEL SYSTEM DESIGNED AND INSTALLED BY THE GENERATOR MANUFACTURER IS IN STRICT COMPLIANCE WITH STANDARDS ES TABLISHED BY THE RECREATIONAL VEHICLE INDUSTRY ASSOCIATION (RVIA). NOTHING MUST BE DONE DURING MAINTENANCE THAT WILL RENDER THE SYSTEM IN NON-COMPLI ANCE WITH THOSE STANDARDS.

not contain more than 10% ethanol and It must be re moved from the generator fuel system during storage,

do NOT use fuel containing methanol. If any fuel con taining alcohol Is used, the system must be inspected more frequently for leakage and other abnormalities.

Evaporation Control Systems

Federal and state laws have Imposed strict evapora

tive controls on gasoline fuel systems. The recreational vehicle Industry has complied with such strict regula tions by using specially designed fuel tanks, tank filler tubes and gas caps. Special canisters are often used to collect the gasoline vapors rather than let them escape into the atmosphere.

Such systems are designed to operate within very critical pressure ranges. For that reason, the vehicle manufacturer’s fuel supply system design must not be altered. Service technicians working on the RV genera tor systems must not do anything that might change the vehicle fuel system design.

Figure 2. Typical Gasoline Fuel System

CARBURETOR

DANGER!

THERE MUST BE NO LEAKAGE OF GASOLINE OR GASOLINE VAPORS INTO THE VEHICLE. THE GENERATOR COMPARTMENT MUST BE VAPORTIGHT TO PREVENT ENTRY OF FUEL VAPORS OR FUMES INTO THE VEHICLE. THE GENERATOR’S VENTILATION SYSTEM MUST PROVIDE A FLOW OF AIR THAT WILL EXPEL ANY FUEL VAPOR ACCUMULATIONS.

Recommended Fuel

Use a high quality UNLEADED gasoline. Leaded REG

ULAR grade gasoline Is an acceptable substitute.

Do NOT use any fuel containing alcohol, such as

“gasohol“. If gasoline containing alcohol is used, it must

CUSTOMER CONNECTION

FUEL FILTER

Page 3.1-1

Section 3.1- INTRODUCTION TO FUEL SYSTEM

Page 3.1-2

Section 3.2- AIR CLEANER & AIR INTAKE

Air Cleaner

DESCRIPTION:

The air cleaner assembly consists of (a) an air cleaner

BASE, (b) a PAPER FILTER, and (c) a COVER. See Figure

SERVICING THE AIR CLEANER:

Clean or replace the PAPER FILTER every 25 hours of

operation or once each year, whichever comes first.

Air Intake

See Figure 2. Air Is drawn Into the aircleaner, passes through the air cleaner filter, and Is then ported to the carburetor air Inlet through an air Intake hose.

Periodically inspect the air Intake hose for condition,

damage, holes, perforations, etc. Replace hose, if neces

sary. Inspect air intake hose clamps for tightness, con

dition. Tighten or replace as necessary.

1. Loosen the two screws that retain the air cleaner COVER and remove the COVER.

2. Remove the PAPER FILTER.

3. Clean the PAPER FILTER by tapping gently on a flat surface. If PAPER RLTER is extremely dirty, replace It

4. Clean the air cleaner BASE and COVER, then Install the new PAPER RLTER into COVER.

5. Install COVER with PAPER RLTER. Retain to BASE with two screws.

Page 3.2-1

Section 3.2- AIR CLEANER & AIR INTAKE

Page 3.2-2

Section 3.3- FILTER & FUEL PUMP

Fuel Filter

The fuel filter should be removed end replaced every

100 hours of operation or once each year, whichever occurs first

The 12 voKs DC electric fuel pump has a zinc plate finish. Flow through the pump Is positively shut off when it is not operating. The pump Is actually rated at a voltage of 8 to 16 VDC, but has a nominal voltage rating of 12 VDC.

Current draw of the pump at nominal voltage Is ap

proximately 1.4 amperes maximum.

Pressure rating of the pump at zero delivery is 2.0 to

3.5 psi.

Two wires are brought out from the pump. The black wire Is grounded by connecting It to a pump mounting bolt The red wire is Identified as Wire No. 14A. The pump will operate whenever:

□ The FUEL PRIME switch on the generator panel is

actuated to Its "ON” position.

□ During engine startup and running conditions when

the Engine Controller circuit board energizes the Wire No. 14 circuit

TESTING THE PUMP:

1. The pump coll can be tested for an open or shorted condition as follows:

a. Test for "Open":

(1) Disconnect the RED pump wire at Its "bullet* lug.

(2) Set a VOM to Its *Rx1" scale and zero the meter. (3) Connect one meter test probe to the RED pump

wire, the other test probe to terminal end of the pump’s BLACK lead. The VOM should Indicate pump coll resistance.

FUEL PUMP NOMINAL COIL RESISTANCE

ABOUT 0.75 to 1.00 ohm

b. Test for "Shorted" condition:

(1) Disconnect the RED and the BLACK fuel pump

leads.

(2) Set a VOM to its "Rxl0,000" or "RxlK" scale and zero the meter.

(3) Connect one VOM test lead to the pump RED

lead, the other test probe to the pump body. The meter should read "Infinity".

2. Pump operation can be tested as follows:

a. Disconnect the fuel line from the outlet side of the fuel pump.

b. Make sure a supply of fuel Is available to the inlet side of the pump.

c. The RED lead from the pump must be connected properly Into the circuit The pump’s BLACK lead must be connected at the pump mounting bolt

d. Actuate the Fuel Prime switch on the generator panel. The pump should operate and should pump fuel from the outlet side.

NOTE: If desired, a pressure aauge can be attached to the pump’s outlet side. Pump outlet pressure should be 2.0 to 3.5psI.

Page 3.3-1

Section 3.3- FILTER AND FUEL PUMP

Page 3.3-2

Section 3.4- CARBURETOR

General Information

Proper engine performance depends on the car-

buretion system. The use of clean, fresh gasoline

and a well-maintained air cleaner are extremely

important to proper operation, as well as engine reliability and power.

Most causes of carburetion problems are related to the use of stale, gummy fuel and the Ingestion of dirt Before servicing the carburetor, be sure to check for evidence of these conditions. Gasoline that is left in the fuel lines for long periods can form gum or varnish deposits that will adversely affect carburetor operation.

NOTE: A commercial fuel stabilizer (such as STABIL®) will minimize the formation of gum de

posits durina storage. Add the stabilizer to the gasoline In the fuel tank or In the storage container, hollow the ratio recommended on the stabilizer

container. Run the engine for about 10 minutes

after adding stabilizer, to allow It to enter the car buretor.

that can be purchased In most automotive repair facilities or In lawn and garden centers.

"StABIL®“ Is a brand name fuel stabilizer

Description

The carburetor used on GN-190 and GN-220 en

gines is a float type with fixed main jet. Carburetor

throttle position and engine speed are controlled

by an electric stepper motor. The stepper motor

moves the throttle in response to signals received from a CCG circuit board. The circuit board senses load voltage, establishes the correct engine speed to obtain correct voltage and delivers an output signal to the stepper motor. The stepper motor adjusts the engine throttle to change engine speed and establish correct output voltage.

When the needle valve moves off Its seat, fuel can flow Into the bowl. As the fuel level rises, the float moves upward to force the needle valve against its seat and stop the flow into the bowl.

CHOKE POSITION:

The choke valve is closed to restrict the flow of

air Into the engine. As the engine cranks, air pres sure in the cylinder is reduced. Since the air intake

passage is partially blocked by the choke valve,

fuel is drawn from the main nozzle and from the idle discharge port. This creates the very rich fuel mix ture required for starting a cold engine.

IDLE OPERATION:

The throttle valve is nearly closed to shut off the fuel supply from all ports except the primary Idle fuel discharge port. Engine suction then draws fuel only from that port.

FLOAT OPERATION;

A hollow plastic float maintains fuel level In the

float bowl. As fuel is used, the float moves down ward to move an inlet needle valve off its seat.

HIGH SPEED OPERATION;

The throttle valve is wide open. This allows a

large volume of air to pass through the carburetor

at a high velocity. The high velocity air flow past the carburetor venturi results in a drop In air pres sure at the venturi throat This reduceo air pressure draws fuel through the main nozzle that opens into the venturi which then mixes with the air in the air passage.

Carburetor Disassembiy

See Figure 3, next page. The carburetor can be

disassembled as follows:

1. Remove the BOWL NUT (Item 3) and the FIBER

WASHER (Item 4). Then, remove the FLOAT BOWL (Item 5).

2. Remove the FLOAT PIN (Item 6). Then, remove

the FLOAT (Item 7) and the INLET VALVE (Item 8).

Page 3.4-1

Section 3.4- CARBURETOR

Carburetor Disassembly (Contin

ued)

3. Remove the IDLE MIXTURE SCREW (Item 22) with SPRING (Item 21).

4. Remove thie IDLE SPEED SCREW (Item 20) with SPRING (Item 19).

5. Rotate the THROTTLE VALVE (Item 10) to Its closed

osltlon and remove the SCREW (Item 9). Remove the

HROTTLE VALVE.

6. Remove the THROTTLE SHAFT (Item 14), along with the THROTTLE SHAFT SPRING (Item 13) and the THROT TLE SHAFT SEAL (Item 12).

7. Remove the CHOKE VALVE SPRING RETAINER (Item

18). Remove the CHOKE VALVE (Item 17). Remove the

CHOKE SHAFT (Item 15) and the SHAFT SEAL (Item 16).

Cleaning and Inspection

1. Separate all non-metallic parts.

2. Clean metallic parts In a solvent or a commercial cleaner. Soak the parts no longer than about 30 minutes.

3. Inspect throttle lever and plate. Replace If worn or damaged.

4. Inspect the Idle mixture screw. Check the point as well as Its seating surface for damage. Replace the screw, If damaged.

5. The float bowl must be free of dirt and corrosion. Use a new float bowl gasket when assembling the bowl.

6. Check the float for damage. Replace, if damaged. The float setting is fixed and non-adjustable.

7. The carburetor body contains a main Jet tube that Is pressed In to a fixed depth. Do NOT attempt to remove this tube. Tube movement will adversely affect carbu retor metering characteristics.

8. After soaking In solvent, blow out all passages with compressed air.

Adjustment

The carburetor is equipped only with an idle jet adjustment. This jet controls the fuel-air mixture from light to no-load conditions. The carburetor’s high speed jet is FIXED and NON-ADJUSTABLE.

If the engine is operated at a significantly differ

ent altitude than the factory (900 feet above sea levei). It may become necessaiy to readjust the idle jet. The fuel-air mixture must be set LEANER for high altitudes. If the unit is moved back to a lower altitude, return the jet to a richer setting.

CAUTIONI

Do NOT adjust the fuel-air mixture excessively lean. An excessively lean mixture can result in engine damage.

3. Bowl Nut

4. Fiber Washer

5. Float Bowl

6. Float Pin

7. Float

8. Infet Valve

9. Screw

10. Throttle Valve

11. Body

12. Throttle Shaft Seal

13. Throttle Shaft Spring

14. Throttle Shaft

15. Choke Shaft

16. Choke Shaft Seal

17. Choke Valve

18. Choke Valve Spring Retainer

19. Idle Speed Screw Spring

20. Idle Speed Screw

21. Idle Mixture Screw Spring

22. Idle Mixture Screw.

NOTE: Item 20 used only on Serial No.’s 1354194-1354198 and 1361541-1361600. On other units. Idle Speed Screw has been rem oved.

See Figure 4, next page. Turn the IDLE JET In

ward (clockwise) until it just contacts its seat. DO NOT FORCE. Then, turn the IDLE JET outward (counterclockwise) 1-1/8 turns. This initial adjust ment should allow the engine to be started and warmed up.

Page 3.4-2

After the initial adjustment, start the engine and

let it warm up for about five (5) minutes. If the

engine runs rough or if exhaust smoke is black,

proceed as follows:

Revised- 02/07/95

Section 3.4- CARBURETOR

1. with enqine running at no-load, turn the IDLE JET clockwise (leaner) until engine speed starts to decrease or fluctuate.

2. Turn the IDLE JET counterclockwise (richer) until engine speed starts to decrease or fluctuate or until

black smoke comes from exhaust.

3. Very SLOWLY turn the IDLE JET clockwise (leaner) until engine speed just stabilizes or until black smoke

just stops coming from exhaust 00 NOT turn the JET excessively lean.

Use the following procedure to ensure the link

age rod is properly adjusted:

1. Start the engine and immediately shut it down. As the

engine coasts to a stop, observe from above the engine as the carburetor throttle lever rotates counterclockwise.

2. There should be a gap of about 0.003 inch (0.08-0.5mm) between the stop tab on the throttle lever arm and the stop block on the carburetor casting. See Figure 5.

CAUTION!

The next step Involves bending a spring clip. Do

NOT overbend the clip or it may lose its clamping

force.

3. Use pliers to lightly compress the spring clip on the

carburetor lever arm (Figure 6). This permits the linkage rod to slide freely through the clip. With the clip com pressed, rotate the throttle lever in the appropriate direc tion until there is a 0.003 Inch (0.08-0.5mm) gap.

4. Release the spring clip to lock In the adjustment

Figure 5. Set Between Stop Tab and Stop Block

THROTTLE LEVER ARM

Engine Speed

Engine speed is controlled by the CCG circuit

board. That circuit board signals a stepper motor which moves the throttle linkage. Engine speed will vary in response to changes In generator AC output voltage.

The circuit board monitors the demand for power and adjusts the engine speed accordingly. This permits the engine to deliver only the power needed.

NOTE: Do NOT attempt to accelerate the enalne manually by grasping the throttle or throttle link age. This win cause the system to enter a fault condition and terminate generator AC output.

Throttle Linkage Adjustment

If necessary, the length of the linkage between

the stepper motor and the carburetor throttle lever arm can be adjusted. This adjustment helps to establish the proper travel relationship of the link age. If the adjustment is not correct, the CCG board will not be able to control the full range of engine speed. The following conditions might occur:

G If the throttle linkage Is set too short, the system will

not be able to provide wide open throttle or full

power conditions.

G If the linkage Is set too long, the system will not be

able to provide closed throttle or no power condi tions.

Figure 6. Adjusting Throttle Linkage

Page 3.4-3

Section 3.4- CARBURETOR

Carburetor Removal

To remove the carburetor from the engine, proceed as follows:

1. Disconnect the carburetor fuel Inlet line.

2. Loosen the clamp and disconnect the carburetor air Inlet hose.

3. Remove the two M6-1.00 x 90mm screws that

retain the carburetor.

Figure 7. Carburetor Removal

SPACER GASKETS

/. \

-t

SPACER

CARBURETOR

SKIRT

CARBURETOR

GASKET

4. Remove the carburetor air Inlet adapter, the air inlet adapter gasket, carburetor and carburetor to skirt gasket.

5. Remove the sheet metal carburetor skirt.

6. Remove two gaskets and the carburetor spacer.

INLET ADAPTOR

HOSE CLAMP

-------

TO REGULATOR

MOUNTING BOLT

Page 3.4-4

Section 3,5- AUTOMATIC CHOKE

General

The GN-190 and GN-220 vertical shaft engines are equipped with an automatic choke. A choke solenoid is attached to the carburetor choke shaft by means of a choke control link. Solenoid opera*

tion is controlled by an engine controller circuit

board. The circuit board energizes and de-ener gizes the solenoid cyclically at a rate dependent on ambient temperature during engine cranking only.

Description

See Figure 1. The CHOKE SOLENOID is retained

to a CHOKE COVER by two No. 4-40 SCREWS,

LOCKWASHERS and FLATWASHERS. The two screw holes in the COVER are slotted to provide for axial adjustment of the CHOKE SOLENOID. A COT

TER PIN retains a CHOKE LINK to the SOLENOID. A CHOKE BI-METAL & HEATER Is retained to the SOLENOID by two No. 4-40 SCREWS,

LOACKWASHERS and FLATWASHERS.

Operational Check and Adjustment

OPERATIONAL CHECK:

Crank the engine. During cranking, the choke

solenoid should pull in about every 2 to 5 seconds. If it does NOT pull in, try adjusting the choke.

PRE-CHOKE ADJUSTMENT:

With the solenoid NOT pulled In, the carburetor

choke valve (choke plate) should be about 1/8 inch

from its full open position. If necessary, use needle

nose pliers to bend the tip of the BI-METAL until a 1/8 inch setting is obtained.

CHOKE SOLENOID ADJUSTMENT:

Loosen the two screws that retain the choke solenoid to Its cover. Adjust axial movement of the solenoid plunger by sliding the solenoid In the

slotted screw holes of the cover.

Adjust plunger axial movement until (with the

carburetor choke valve closed) the plunger is bot tomed in the solenoid coil. That Is, until the plunger

is at its full actuated position.

With the choke valve (choke plate) closed and the

plunger bottomed in its coil, tighten the two

screws.

figure 2. Choke Adjustment

NOTE: Also see Part 6, "ENGINE ELECTRICAL SYSTEM". The section on DC control system In cludes additional Information on choke operation

and the engine controller circuit board.

When the engine Is being cranked, engine con

troller circuit board action energizes the choke solenoid in regular timed cycles. Each time the choke solenoid is energized, it closes the carbu retor choke valve. The circuit board’s choke timer circuit provides energizes the choke solenoid (pulls it in) about every 2 to 5 seconds’

When the engine starts, cranking is terminated.

The choke action Is then terminated and the choke setting is determined by a choke heater (CH).

Loosen 2 screws and slide solenoid In the slots of choke mount

cover. With carburet

or choke plate clos

ed, plunger must

be bottomed In coil.

Page 3.5-1

Section 3.5- AUTOMATIC CHOKE

Page 3.5-2

Section 3.6- SPEED CONTROL SYSTEM

General

The AC generator’s output voltage Is controlled by a “computerized" speed control system. This system changes engine speed In response to changes In the AC output voltage at varying engine loads. The speed control system consists of (a) the CCG circuit board and (b) a stepper motor.

CCG Circuit Board

This circuit board utilizes a closed-loop, propor

tional-derivative controller circuit which regulates the generator’s RMS voltage by changing engine speed. The system attempts to maintain an output voltage of about 115 volts at the lowest rpm and 120 volts up to the maximum rpm.

The system also Includes a controller which will

hold the engine at maximum speed. In this mode,

the system will attempt to maintain an output volt age of 105-115 volts.

The CCG circuit board controls a stepper motor

by calculating the number of steps the motor needs

to take and then supplying the necessary signals to the motor to take those steps.

NOTE: Also see "CCG Circuit Board" on Pages

1.2-4 through 1.2-6.

Stepper Motor

See "Stepper Motor" on Page 1.1-2.

Testing the CCG Circuit Board

See "Testing the CCG Circuit Board" on Pagel .5-

4 and 1.5-5.

Stepper Motor Probiems

INTRODUCTION:

Some stepper motor problems that might occur

Include the following:

n Throttle linkage or carburetor throttle shaft sticking,

or linkage disconnected.

D Stepper motor failed or seized.

□ Electrical connections to stepper motor broken or

disconnected.

D Electrical leads to stepper motor are connected

wrong.

THROTTLE LINKAGE:

Check throttle linkage and carburetor throttle shaft for binding, disconnected linkage. This type of problem will usually result in the carburetor throttle lever not moving. If the throttle lever does

. not move, the throttle may be stuck at a perma

nently open throttle or a permanently closed throt

tle as follows:

1. If the throttle is open, engine will start but will acceler

ate quickly and uncontrollably. It will shut down when speed exceeds about 4500 rpm.

2. If the throttle Is closed, engine will not accelerate under load. After about 10 seconds, generator AC output will

terminate. STEPPER MOTOR FAILED OR SEIZED:

The engine will start but stepper motor will not

turn. If an open throttle condition exists, either of the following might occur:

1. Engine may accelerate and shut down at 4500 rpm.

2. Engine may shut down after 15 seconds due to an

overvoltage condition.

If throttle is closed, engine will be unable to

accelerate under load and AC output will be lost after 10 seconds.

A failed stepper motor may also turn erratically.

If this Is the case, engine speed and AC output voltage will be erratic under constant load.

ELECTRICAL CONNECTIONS BROKEN:

If one or more of the electrical connections to the

stepper motor are broken or disconnected, either of the following might occur:

1. The stepper motor may not turn at all.

2. The stepper motor may turn erratically.

If the stepper motor does not turn, symptoms will

be the same as for a failed or seized stepper motor.

LEADS CONNECTED WRONG:

Incorrectly connected electrical leads to the

stepper motor can result In any one of the follow

ing:

1. Stepper motor may not turn at all.

2. Stepper motor may turn erratically.

3. Stepper motor may turn backwards. If the stepper motor does not turn, engine will start and

the following may occur:

1. If throttle Is open, engine will accelerate and shut down when speed reaches 4500 rpm or after 15 seconds due to overvoltage condition.

2. If throttle Is closed, generator AC output will terminate. If the stepper motor turns erratically, engine speed and

AC output voltage will be erratic under a constant load. The AC output will not terminate.

If the stepper motor Is turning backwards, engine will accelerate and shut down at 4500 rpm.

Page 3.6-1

Section 3.6- SPEED CONTROL SYSTEM

Figure 1, Speed Control System

CCG BOARD CONNECTOR

STEPPER MOTOR

RED ORANGE YELLOW

BROWN

BLACK

Testing the Stepper Motor

GENERAL:

The Stepper Motor consists of an electric motor

plus a small gearbox. It is shown pictoriaily and schematically in Figure 3. The four (4) motor wind ings can be tested for (a) continuity and (b) shorts

to the case.

it is difficult to perform an operational test of the

motor since the amount of motor arm movement is so small.

TESTING FOR OPEN CONDITION:

To test the motor windings for an open circuit

condition, proceed as follows:

1. Unplug the Stepper Motor connector from its recepta cle on the CCG circuit board.

2. Set a volt-ohm-milllammeter (VOM) to its "Rx1“ scale

and zero the meter.

3. Connect one VOM test probe to the connector pin to which the RED wire attaches. This is the -t-DC side of all windings. Then, connect the other VOM test probe as follows:

a. To the ORANGE wire connector pin. Approxi

mately 19-21 ohms should be indicated. b. To the YELLOW wire con nector pin. About 19-21 ohms

should be read.

c. To the BROWN wire pin for

a reading of 19-21 ohms. d. To the BLACK wire connec

tor pin for a reading of about

19-21 ohms.

TESTING FOR SHORTED CONDITION:

1. Set the VOM to its "Rxl 0,000“ or “Rxl K“ scale and zero

the meter.

2. Connect one VOM test probe to the RED wire connecvtor pin, the other test probe to the Stepper Motor case. The meter should read "infinity“. Any reading other than

"infinity“ Indicates a shorted winding. Replace the Stepper Motor if It fails any part of the test.

Figure 3. The Stepper Motor

ORANGE

RED

^YELLOW

19-21 ohms

Schematic

JOOOOir

19-21

ohms

■BROWN

I I

-BLACK

imm,

Pictorial

Page 3.6-2

Part 4

GASEOUS

SECTION

4.1

4.2

4.3

TITLE

INTRODUCTION TO FUEL SYSTEM

SHUTOFF VALVE & REGULATOR

CARBURETOR

FUEL

SYSTEM

COMPUTER

CONTROLLED

VARIABLE

SPEED RV

GENERATORS

Series NP-30G and NP-40G

NOTE: Information on the following is the same as for the "GASOLINE FUEL SYSTEM" (Part 3):

Air Cleaner & Air Intake (Section 3.2) Speed Control System (Section 3.6)

Section 4.1- INTRODUCTION TO FUEL SYSTEM

General Information

Some RV generator models are equipped with fuel systems that utilize LP gas as a fuel. The Initials “LP" stand for "liquefied petroleum". This gas Is highly volatile and can be dangerous if han dled or stored carelessly.

All applicable laws, codes and regulations per

taining to the storage and handling of LP gas must

be complied with. The installation of such fuel

systems must also be In compliance with such

laws, codes and regulations. Service technicians

who work on these systems must do nothing that

might cause the system to be In non-compliahce

with regulations.

Regulations established by the Recreational Vehiclelndustry Association (RVIA) must be followed in the installation, use and servicing of such sys

tems.

DANGERI

LP GAS IS HIGHLY EXPLOSIVE. THE GAS IS HEAVIER THAN AIR AND TENDS TO SETTLE IN LOW AREAS. EVEN THE LIGHTEST SPARK CAN IGNITE THE GAS AND CAUSE AN EXPLOSION. ONLY COMPETENT, QUALIFIED GAS SERVICE

TECHNICIANS SHOULD BE ALLOWED TO IN STALL, TEST, ADJUST OR SERVICE THE GAS

EOUS FUEL SYSTEM. INSTALLATION OF A GAS

EOUS FUEL SYSTEM MUST BE IN STRICT COM PLIANCE WITH APPLICABLE CODES. FOLLOW ING INSTALLATION NOTHING MUST BE DONE THAT MIGHT RENDER THE SYSTEM IN NONCOMPLIANCE WITH SUCH CODES.

DANGERI

USE ONLY APPROVED COMPONENTS IN THE GASEOUS FUEL SYSTEM. IMPROPER INSTAL LATION OR USE OF UNAUTHORIZED COMPO NENTS CAN RESULT IN FIRE OR AN EXPLOSION USE APPROVED METHODS TO TEST THE SYS

ТЕМ FOR LEAKS. NO LEAKAGE IS PERMITTED

DO NOT PERMIT FUEL VAPORS TO ENTER THE

VEHICLE INTERIOR.

Advantages of Gaseous Fuels

The use of gaseous fuels may result In a slight power loss, as compared to gasoline. However, that disadvantage Is usually compensated for by the many advantages of gaseous fuels. Some of these advantages are:

□ A low residue content results in minimum car

bon formation in the engine.

□ Reduced sludge buildup in the engine oil. □ Reduced burning of valves as compared to

gasoline.

□ No wash-down of engine cylinder walls during

cranking and startup.

□ Excellent anti-knock qualities. □ A nearly homogeneous mixture In the engine

cylinders.

□ Fuel can be stored for long periods without

breakdown.

Fuel System Components

When the generator set is shipped from the fac

tory, the following feui system components are

Included with the unit:

1. A Fuel Lockoff Solenoid

2. The LP Gas Regulator

3. The carburetor.

4. Interconnecting lines and fittings. Components that must be added by the genera

tor installer include the following:

1. A VAPOR WITHDRAWAL type fuel tank.

2. A PRIMARY REGULATOR that will deliver a fuel pressure to the Fuel Lockoff Solenoid of about 11 psi.

3. Interconnecting lines and fittings.

Vapor Withdrawal

LP gas Is stored in pressure tanks as a liquid. Gaseous fuel system components Installed on the generator are designed for "vapor withdrawal" type systems. Such systems use the gas vapors that

form above the liquid fuel In the tank. Do not at tempt to use any "liquid withdrawal" type tank with the RV generator.

NOTE: "Liquid withdrawal" type systems use the liquid fuel from the tank. The liquid fuel must be vaporized before It reaches the carburetor. Fuel vaporization Is usually accomplished by porting the liquid fuel through some kind of heating device.

Important Considerations

When servicing the gaseous fuel system the fol

lowing rules apply: □ All lines, fittings, hoses and clamps must be

free of leaks. Apply pipe sealant to threads when assembling threaded connectors to re duce the possibility of leakage.

□ Following any service, the system must be

tested for leaks using APPROVED test meth ods.

□ Optimum gas pressure at the Inlet to the fuel

lockoff solenoid and secondary regulator Is 11 inches of water column. Do NOT exceed 14

inches water column.

Page 4.1-1

Section 4.1- INTRODUCTION TO FUEL SYSTEM

Important Considerations (Contin

ued)

NOTE: A PRIMARY REGULATOR, between the tank and the fuel lockoff solenoid, Is required to ensure that correct gas pressure Is delivered to the lockoff solenoid.

n The generator installer’s connection point is at

the fuel lockoff solenoid which has a 3/4 inch (female) connection.

□ A length of flexible hose is required between

the fuel lockoff solenoid and rigid fuel piping, to allow for vibration and/or shifting of the unit. This line must be at least six (6) inches longer than necessary.

Fuei Suppiy Lines

When servicing or repairing the gaseous fuel

system, the following ruies apply to gaseous fuel supply lines:

□ The LP gas lines must be accessible but must

also be protected against possible damage.

□ Do NOT connect electrical wiring to any gas

eous fuel line. Do NOT route electrical wiring alongside the gaseous fuel lines.

n Route the gaseous fuel lines AWAY from hot

engine exhaust mufflerts and piping.

Figure 1. A Typical LP Gas Fuel System

□ Gas lines should be retained with metal clamps

that do not have any sharp edges.

□ Gaseous fuel lines and primary regulators must

be properly sized to deliver adequate fuel flow to the generator engine. The generator requires at least 67 cubic feet of gas per hour for its operation.

NOTE: An existing primary regulator may be used

to deliver gas to the fuel lockoff solenoid provided

It has sufficient flow capacity for the generator and

other gas appliances In the circuit. If the existing

primary regulator does not have a sufficient capac ity (a) replace It with one that has adequate flow capacity, or (b) Install a separate primary regulator having at least a 67 cubic feet per hour capacity.

Excess Fiow Vaive

Rules established by the National Fire Protection

Association (NFPA) and the Recreation Vehicle In dustry Association (RVIA) require that the LP gas tank be equipped with an excess flow valve, mis valve and the gaseous fuel lines must be carefully sized so the excess flow valve will close in the event of line breakage.

Shutoff valves on the fuel supply tank and else

where in the system must be fully open when oper

ating the generator. The excess flow valve will

function properly only if all valves are fully open

and fuel lines are properly sized.

Page 4.1-2

VAPOR WITHDRAWAL

vTANK

11-14 Inches of water

FUEL LOCKOFF

SOLENOID

-------------

LP GAS CARBURETOR

regulator.

Section 4.1- INTRODUCTION TO FUEL SYSTEM

Gaseous Carburetion

Gas at positive pressure is deiivered from the

fuei iockoff soiehoid to the iniet of the reguiator

(about 11-14 inches of water).

As the engine piston moves downward on its intake stroke, air is drawn into the area above the piston through the carburetor venturi. A negative pressure is created at the venturi which is propor-

tionai to the amount of air that is fiowing.

The negative pressure at the carburetor venturi

acts on the reguiator diaphragm to puii the dia

phragm toward the source of iow pressure. A lever,

attached to the diaphragm, opens a metering vaive which aiiows gas to enter and flow through the carburetor.

The greater the air flow through the carburetor venturi, the iower the pressure at the venturi throat. The lower the pressure at the venturi throat, the greater the movement of the diaphragm and the more the metering vaive opens.

□ It must be sensitive to pressure changes In the

carburetor venturi throughout the entire oper ating range.

n it must positiveiy stop the fiow of gas when the

engine is not running.

□ The slightest air flow through the carburetor

venturi must move the regulator valve off its seat and permit gas fiow.

Leakage Testing

Whenever any lines, fittings or other compo

nents of the fuel system have been removed and replaced, the system should be carefully checked for leaks before It is placed into service.

To check for leakage, start the engine and let It

run. Then use a soap and water solution or an

approved commercial leak detector solution to de termine if any leakage exists. No leakage is permit ted.

DANGER!

DO NOT USE FLAME TO CHECK FOR LEAKAGE. GASEOUS FUEL LINES BETWEEN THE TANK AND SECONDARY REGULATOR ARE UNDER A

POSITIVE PRESSURE (ABOUT 11 INCHES OF WATER COLUMN). HOWEVER, GAS PRESSURE AT THE OUTLET SIDE OF THE SECONDARY

REGULATOR IS A NEGATIVE PRESSURE

(ABOUT 1 INCH WATER COLUMN). THIS NEGA TIVE PRESSURE CAN DRAW FLAME INSIDE A

LINE OR FITTING AND CAUSE AN EXPLOSION.

The foiiowing requirements of the secondary

reguiator must be emphasized:

IMPORTANT!

APPLY PIPE SEALANT TO THREADS OF ALL

FITTINGS TO REDUCE THE POSSIBILITY OF

LEAKAGE.

Page 4.1-3

Section 4.1- INTRODUCTION TO FUEL SYSTEM

Page 4.1-4

Section 4.2- SHUTOFF VALVE & REGULATOR

General

See Figure 1. The fuel shutoff valve (lockoff

solenoid) and the secondary regulator are retained to a flat mounting bracket which, In turn, mounts to the generator base cover. The fuel lockoff solenoid

is retained to the mounting bracket by means of a

u-boit The secondary regulator is retained to the

mounting bracket with two MA“-2Q x 3/4" long

capscrews.

Parts List for Figure 1

ITEM QTY

1 1 2 1 Fuel Lockoff Solenoid 3 1 4 2 3/4" NPT Street Elbow 5 6 7 1 8 9 10 2 11 2 12 2 13 14 1 15 1 Sleeving (9" long)

1 3/4" NPT Close Nipple 1 3/8" NPT Street Elbow

1 Hose Clamp 1 1/2" ID Hose (11.5" long)

2 5/16"-18Hex Nut

U-Bolt-1.25" wide (5/16‘-18)

Regulator Mounting Bracket

DESCRIPTION

LP Gas Regulator

1/2" X 3/8“ NPT Fitting

1/4"-20 X 3/4" Capscrew

1/4" Lockwasher

5/16" Lockwasher

Adjustments

There are no adjustments on the fuel lockoff

solenoid or the secondary regulator. This system is NOT equipped with a load block.

The LP Gas Regulator

The secondary regulator is a GARRETSON® Model KN. It Is designed for simplicity and simple operation. The regulator is suitable for use with low pressure vaporized gaseous fuels where depend able starting is a requirement. Recommended inlet pressure to the regulator is 11 inches water col umn.

The regulator comes with a 3/4 inch NPT fuel inlet and a 3/8 Inch NPT fuel outlet.

The LOCKOFF ADJUSTMENT SCREW shown in Figure 2 has been preset at the factory. No addi

tional adjustment Is authorized.

DANGER!

DO NOT ATTEMPT TO ADJUST THE GAS REGU

LATOR. REGULATOR ADJUSTMENTS SHOULD BE ATTEMPTED ONLY BY QUALIFIED GAS SER VICE TECHNICIANS WHO HAVE THE KNOWL EDGE AND SPECIALIZED EQUIPMENT FOR SUCH ADJUSTMENTS.

Testing the Fuel Lockoff Solenoid

GENERAL:

The fuel lockoff solenoid Is energized open by 12 volts DC power from the engine controller circuit board during engine cranking. The solenoid can also be energized open without cranking by actu ating the fuel primer switch on the generator panel.

TEST PROCEDURE:

1. Set a volt-ohm-mllliammeter (VOM) to read

battery voltage (12 VDC).

Page 4.2-1

Section 4.2- SHUTOFF VALVE & REGULATOR

Testing the Fuel Lockoff Solenoid (Continued)

2. Connect the VOM test leads across Wire 14 (Red) at

the solenoid and a clean frame ground.

3. Set the fuel primer switch on the generator panel to its ON position.

a. The meter should indicate battery voltage.

b. The solenoid should energize open.

RESULTS OF TEST:

1. If battery voltage is Indicated but the solenoid does NOT energize, replace the lockoff solenoid.

2. If battery voltage is NOT indicated, a problem exists In the DC control system. See Parts 6, “ENGINE ELECTRI CAL SYSTEM".

Page 4.2-2

General

The carburetor Is designed for use with LP gas

in its vapor form. The following specifications

apply:

Section 4.3- CARBURETOR

Carburetor Inlet Diameter Carburetor Outlet Diameter .. 0.78 inch i20mm)

Venturi Diameter......................0.63 Inch (16mm)

Main Jet Diameter

Number..................................370

Measured Size........................0.145 Inch (3.7mm)

____

1.02 inch f26mm)

Carburetion

Refer to "Gaseous Carburetion" In Section 4.1

(Page 4.1-3).

Carburetor Adjustment

The LP gas carburetor used on NP-30 and NP-40

generator sets is equipped with a fixed Jet and is non-adjustable.

Carburetor Removal

Refer to Part 3, Section 3.4, Page 3.4-4 for carbu

retor removal procedures.

Disassembly and Reassembly

The carburetor is replaced as an entire assembly.

Disassembly and reassembly Is not required.

Section 4.3- CARBURETOR

Page 4.3-2

SECTION

TITLE

Part 5

ENGINE OIL & COOLING

SYSTEM

COMPUTER

CONTROLLED

VARIABLE

SPEED RV

GENERATORS

Series NP-30G and NP-40G

5.1

5.2

ENGINE OIL SYSTEM

ENGINE COOLING SYSTEM

Section 5.1- ENGINE OIL SYSTEM

Introduction to Oil System

The engine oil system serves to (a) reduce fric

tion between parts, (b) cool the engine, and (c) establish a slightly negative pressure In the crank case to prevent oil leakage. Major components that will be discussed in this section Include the follow

ing:

□ Oil PIckupScreen. □ Oil Pump. □ Crankshaft OH Seals. □ Pressure Relief Valve. □ Breather Assembly. □ Oil Sump. n Oil Filter Support Assembly.

Oil Flow

See Figure 1. The oil pump draws oil from the oil

sump through an oil pickup screen and delivers It

to the areas requiring lubrication as follows:

1. Through a cored channel In the oil sump to the crank

case Journal at one end of the crankshaft

2. Through the hollow camshaft to the camshaft bearing.

3. Through a cored passage In the crankcase to the crankshaft Journal.

4. Through the crankshaft to the crankpin and connect ing rod bearing.

INSPECTION:

To gain access to the screen, remove the oil filter support and its gasket. Pull the screen off Its tubular protrusion. Clean the screen In solvent, then Inspect for damage. Replace the screen If

necessary.

Oil Pump

DESCRIPTION:

The oil pump Is of the trochoid type. Its Inner

rotor rotates on a shaft provided In the camshaft bore of the oil sump. The outer rotor Is Installed

over two drive pins on the end of the camshaft and

Is driven by camshaft rotation.

Oil Pickup Screen

DESCRIPTION:

The oil pickup screen consists of a cylindrical screen which Is open at one end only. The screen’s open end fits over a tubular protrusion In the oil sump. Just behind the oil filter support. Also see

" Oil Filter Support Assembly".

INSPECTION:

See Figure 3. Inspect the Inner and outer rotors of the pump for damage and wear. Use a feeler gauge to check tip clearance of the rotor (measured on the shaft in the oil sump). Check the bore Inner diameter and the thickness of the Inner rotor. If wear limits are exceeded, replace the appropriate part(s).

PUMP TIP CLEARANCE

(MEASURED ON SHAFT IN OIL SUMP)

DESIGN CLEARANCE: 0.0000-0.0010 Inch

(0.000-0.025mm)

WEAR LIMIT: 0.004 Inch (0.105mm) Maximum

INNER PUMP ROTOR BORE

DESIGN BORE: 0.354-0.355 Inch (9.000-9.019mm)

WEAR LIMIT: 0.357 Inch (9.034mm) Maximum

INNER ROTOR THICKNESS

DESIGN THICKNESS: 0.312-0.315 Inch (7.95-8.00mm)

WEAR LIMIT: 0.311 Inch (7.90mm) Minimum

Replace any part that is damaged or worn exces sively. The shaft on which the inner rotor rotates is NOT repiaceabie (oil sump must be replaced).

Page 5.1-1

Section 5.1- ENGINE OIL SYSTEM

Oil Pump (Continued)

INSPECTION (CONT’D):

Inspect the outer drive pins on the camshaft

Look for breakage, bending, other damage. These

are roll pins which can be removed and replaced.

Crankshaft Oil Seals

An oil seal Is provided In the crankcase and in

the oil sump, to prevent leakage past the crankshaft

journals. See Figure 4.

A defective or leaking seal can be replaced. If the

crankshaft has been removed from the engine, old seals can be removed by tapping out with a screw driver or punchinq them out from inside. Oil seal pullers are available commercially, for seal removal

with the crankshaft installed.

Always use a seal protector when Installing the

crankshaft into its crankcase bore and when In

stalling the oil sump over the crankshaft.

Pressure Relief Valve

DESCRIPTION:

A ball type pressure relief valve Is located In a

bore of the crankcase. The ball and spring are retained in the crankcase bore by a spring retainer.

The Relief Valve serves to limit oil pressure to a

maximum value. The ball will remain against Its

seat as long as oil pressure In the crankcase oil

passage is below approximately 30 psi (29 kg/cm^). Should oil pressure increase above that value, the ball will be forced off Its seat to relieve excess

pressure Into the crankcase.

INSPECTION:

Remove the 8mm screw that retains the spring RETAINER to the crankcase interior. Remove the RETAINER, SPRING and BALL. Clean all parts In solvent.

Inspect the BALL and RETAINER for damage, excessive wear. Replace any damaged or worn components. Inspect the SPRING and replace If damaged or worn.

Apply a known test load to the SPRING, sufficient

to compress the spring to a length of 1.03 inch

(26.3mm). The amount of the test load at the stated spring length should be as follows:

Page 5.1-2

RELIEF VALVE SPRING TO 1.03 INCH (26.3mm)

FORCE REQUIRED TO COMPRESS

0.86-0.95 pounds (0.43-0.39 kg)

If the test load at the stated length is not within limits, replace the SPRING.

Breather Assembly

DESCRIPTION:

A crankcase breather Is located In the crankcase

assembly.

Section 5.1- ENGINE OIL SYSTEM

The breather serves to maintain a partial vacuum

In the engine crankcase, to prevent oil from being

forced past oil seals, gaskets or rings.

See Figure 6. A reed type breather valve permits excess pressure to be vented out of the crankcase and to atmosphere through a breather tube. A

breather retainer limits the movement of the breather valve. Two small oil return holes In the breather cup allow condensed oil vapors to drain back to the crankcase. A "steel wool" type breather

separator separates the breather cup from the

breather cover and breather tube opening.

Figure 6, Breather Assembly

TO AIR CLEANER BASE

— M6 BOLT

- BREATHER

BREATHER

COVER

VALVE

BREATHER BAFFLE CUP

GASKET

INSPECTION:

Clean the oil sump and blow dry with com

pressed air. Use compressed air to blow out all oil passages. Inspect the sump for cracks, damaae, etc. Check the following bores In the oil sump Tor wear:

CRANKSHAFT BEARING BORE DIAMETER

GN-190 ENGINE

DESIGN DIAMETER: 1.103-1.105 Inch (28.030-

28.058mm)

WEAR LIMIT: 1.106 Inch (28.088mm) Maximum

CRANKSHAFT BEARING BORE DIAMETER

GN-220 ENGINE

DESIGN DIAMETER: 1.104-1.105 Inch (28.040-

28.065mm)

WEAR LIMIT: 1.106 Inch (28.092mm) Maximum

CAMSHAFT BEARING BORE DIAMETER

GN-190 & GN-220 ENGINE

DESIGN DIAMETER: 1.299-1.300 Inch (33.00-33.03mm)

WEAR LIMIT: 1.302 Inch (33.06mm) Maximum

OIL PUMP INNER ROTOR SHAFT DIAMETER

GN-190 & GN-220 ENGINE

DESIGN DIAMETER: 0.353-0.354 Inch (8.969-8.987mm)

WEAR LIMIT: 0.352 Inch (8.949mm) Minimum

INSPECTION:

Remove the breather hose. Inspect It for cracks,

damage, hardening. Replace, If necessary.

Clean the breather cover and breather cup In commercial solvent. Check that the two small drain

holes In the breahtre cup are open; open with a length of wire. If necessary.

Inspect the rivets that retain the reed type

breather valve, make sure they are tight. Also

check that the valve seats flat on the breather cup around the entire surface of the valve.

Oil Sump

DESCRIPTION:

The die cast aluminum oil sump Is retained to the crankcase with six (6) flanged head bolts. Install a new gasket between the oil sump and crankcase each time the oil sump Is removed.

Bores are provided In the oil sump for fa) oil

pump rotors and camshaft, (b) crankshaft, (c) gov ernor gear assembly, (d) oil pickup. Cored oil pas sages are provided from the pickup to the pump and from the pump to the crankshaft bore.

Oil Filter Support

An oil filter support and its gasket are retained to

the oil sump by four (4) M6-1.00 bolt.

A threaded bore Is provided In the support for a

low oil pressure switch. This switch will protect the

engine against damaging low oil pressure by shut ting the engine down automatically If oil pressure should drop below a pre-set low limit.

A high oil temperature switch Is retained to the support by two (2) MS screwqs and lockwashers. This thermal sensor will protect the engine against damaging high temperature conditions through automatlc shutdown.

1. Oil Sump 5. Filter Support

2 MS Scraw 6. Lockwasher

3. Lockwasher 7. Screw

4. Oil Temp. Switch

__________________________

Figure 7. Oil Filter Support

8. Pipe Plug

9. Olf Press. Switch

10.011 Pickup Screen

Page 5.1-3

Section 5.1- ENGINE OIL SYSTEM

Page 5.1-4

Section 5.2- ENGINE COOLING SYSTEM

General

The engine and generator are alr-cooled. It is absolutely essential that an adequate flow of air for cooling, ventilation and combustion be supplied to the RV generator. Without sufficient air flow, the engine-generator will quickly overheat. Overheat ing can result in serious damage to the equipment, as well as fire and possible Injury. Air must be drawn into the generator compartment of the recre ational vehicle at a sufficiently high rate. The air must then be exhausted from the compartment at a sufficiently high rate.

Generator Air Flow

A cooling fan is attached to the generator’s per manent magnet rotor. This pressure fan draws air Into the top of the generator, into the side of the control panel, and across the engine-generator and

electronic components.

A suction fan is attached to the engine crank

shaft. This fan draws the heated air Into a collector pan at the bottom of the engine-generator, where It

Is directed across the exhaust muffler and then

deflected out to ambient air.

a. Ideally, three openings should be provided In such a door as shown In Figure 2.

(1) One opening of 40 square Inches (unre stricted) as shown.

(2) Two 10 square inch openings (unrestricted)

as shown.

NOTE: If screening, louvers or expanded metal are used to cover air openings, It must be remembered that such materials will restrict air flow. This re striction must be compensated for by making the

actual air opening size proportionately larger. See

"Compensating for Restrictions".

NOTE: If the generator Is Installed In a compart ment. at least 1-1/2 Inches of clearance must be

provided between the generator and the compart

ment and any Insulation or metal lining the com

partment walls. Provide at least two (2) Inches of

clearance between the top of the generator and the compartment celling.

Figure 2. Air Inlet In Door

Air Flow into Generator Compart

ment

GENERAL:

The installer of an RV generator Into a vehicle must provide air openings that will supply the needed air for cooling, ventilation and combustion.

Technicians who service the engine-generator must not do anything that will restrict this air flow. Any one or a combination of several different meth ods may be used to deliver the required air flow. The method used by the installer will depend on the method used to mount the generator In the vehicle, as follows:

1. If the generator set Is mounted In a compartment above the vehicle frame, air openings can be provided In the compartment door.

2. If the generator Is suspended below the vehicle frame, any one of several methods can be used to supply re quired air flow.

a. A door in the vehicle skirt having the required air inlet openings (Figure 3).

b. By using ductwork. Air must be available at top

of the engine-generator. See Figure 4. c. By providing an opening in the vehicle skirt

and at least 2 Inches of space above the enginegenerator (Figure 5).

Compensating for Restrictions

Materials such as screening, louvers and ex

panded metal will restrict the free flow of air. When

such materials are used to cover air openings, they

must be compensated for by making the actual air

opening size proportionately larger.

Some materials may offer only a 60 percent "free

inlet area". More efficient materials may offer a 90

percent "free inlet area". The percentage of free air inlet opening can usually be obtained from the

manufacturer of the material.

Page 5.2-1

Section 5.2- ENGINE COOLING SYSTEM

Compensating for Restrictions

(Continued)

EXAMPLE: Screening with an 80 percent free air Inlet area Is to be used to cover an opening that must be at least 40 square Inches In area. Divide 40 by 0.80 to obtain 50 square Inches. In this case, the actual opening size must be at least 50 square Inches.

Figure 5. Opening In Vehicle Skirt

fleCOMMENOED C5LEAHANCE. 2 M. (SIMM) MMtMUM CLEARANCE . t M. (2S.4MM)

VEHCIE FLOOR

~ “t

ENGINE

SIDE

VIEW

Figure 4. Ductwork

Page 5.2-2

Part 6

ENGINE

ELECTRICAL

SYSTEM

COMPUTER

CONTROLLED

VARIABLE SPEED RV

GENERATORS

Series NP-30G and NP-40G

SECTION

6.1

6.2

6.3

6.4

6.5

6.6

TITLE

ENGINE DC CONTROL SYSTEM

ENGINE CONTROLLER BOARD

ENGINE CRANKING SYSTEM

ENGINE IGNITION SYSTEM

ENGINE PROTECTIVE DEVICES

OPTIONAL REMOTE PANEL

Section 6.1- ENGINE DC CONTROL SYSTEM

General

The engine DC control system consists of all

those electrical components required for cranking, starting and running the engine. These compo nents include the following:

1. Engine cranking system components a. A 12 VDC battery. b. A Start-Run-Stop Switch (SW1). c. A Starter Contactor (Starter Relay)- (SC). d. A Starter Motor (SM).

2. An Engine Controller Circuit Board (ECB).

3. A Fuel Primer Switch (SW2).

4. Engine Ignition System Components. a. Ignition Module (IM). b. Ignition Stator (IS). c. Ignition Coil (1C). d. Spark Plug (SP).

5. Engine Protective Devices

a. Low Oil Pressure Switch (LOP).

b. High Oil Temperature Switch (НТО).

6. An optional Remote Panel.

Figure 1.

How it Works

ENGINE NOT RUNNING:

1. Battery output (12VDC) Is

available to the contacts of a starter contactor (SC). However, the contacts are open.

2. Battery output is deliv

ered to Terminal J3 of an Engine Controller circuit board, via Wire 13, a 15 amp

fuse, and Wire 15. Circuit

board action holds this cir

cuit open.

3. Battery output is avail able to a Battery Charge

Rectifier (BCR) via Wire 13, 15 amp Fuse (FI), Wire 15,

a Resistor (R2) and Wire

15A.

CUSTOMER SUPPLIED

NOTE: On units with LP gas fuel system, the Fuel Lockoff Solenoid (FS) will be turned on by closing the Primer Switch.

CRANKING:

When the Start-Run-Stop Switch is held at

"START“, the Wire 17 circuit from the Engine Con

troller circuit board Is connected to frame ground.

Circuit board action then Initiates the following

events:

1. Battery voltage Is delivered to the Starter Con

tactor (SC) coil via Wire 56.

a. The SC coil energizes and its contacts (SC) close.

b. Closure of SC contacts deliver battery voltage

to the Starter Motor (SM) via Wire 16. The engine

cranks.

2. Battery voltage Is delivered to the Wire 14 circuit. a. The Fuel Pump (FP) turns on.

b. Power is available to the Ignition Module (IM)

and ignition occurs.

Schematic- Engine DC Control System

BCR . BAT^^HARQC RECTIRER

BATTERY

PP - FUEL PUMP (QASOUNS) HM • HQURMSTER(OPnON&) НТО • НЮН OIL TEMP. SWITCH

1C - кантон coil

IM • кантон MODULE 18 ■ IQHmOH STATOR LI - RUN LAMP fOPTIOHAL)

LOP - OIL PRESSURE SWITCH

R2 «lOHfcLW WATT RESISTOR SC • STARTER COHTACTOR SM ■ STARTER MOTOR 8W1 « 8TART*STOP SWITCH

W2 - PRIMER SWITCH

PI • SPARK PLUG

PRIMING:

When the Primer Switch

(SW2) is closed, battery

voltage is delivered to the

engine Fuel Pump via Wire 13, 15 amp Fuse (FI), the

Switch contacts (SW^ and Wire 14A. The Fuel Pump will operate to draw fuel from the tank and "prime" the fuel lines.

RE MO T E PAN E L (OP T IO NA L )

Page 6.1-1

Section 6.1- ENGINE DC CONTROL SYSTEM

How it Works (Continued)

CRANKING (CONT’D):

3. Engine Controller circuit board action operates the automatic choke.

NOTE: Also see Section 3.5. “AUTOMA TIC CHOKE” and Section 6.2, "ENGINE CONTROLLER BOARD”.

RUNNING:

With fuel flow and Ignition available, the engine

starts and runs. The operator releases the Start* Run-Stop switch to its "RUN" position.

1. The Wire 18 circuit Is now open to ground. Circuit board action terminates the 12 VDC to the Starter Contactor (SC). The SC contacts open and crank ing ends.

2. Choking action ends and the carburetor choke plate is positioned by the Choke Heater (CH).

3. Circuit board action continues to power the Wire 14 circuit- fuel flow and ignition continue.

NORMAL SHUTI

When the Start-Run-Stop switch is held at

"STOP", the Wire 18 circuit Is connected to frame

ground. Engine Controller circuit board action then terminates the DC flow to the Wire 14 circuit.

1. Fuel Pump (FP) shuts down.

2. Ignition terminates.

3. Engine shuts down.

NOTE: Connection of the circuit board’s Wire 18 or

Wire 18B circuit to frame ground will always result

In engine shutdown. Note that Wire 18B is routed

to the CCG circuit board, giving that circuit board

engine shutdown capability.

ENGINE PROTECTIVE DEVICE SHUTDOWN:

Refer to "Oil Filter Support" on Page 5.1-3 and

Section 6.5. The engine mounts a Low Oil Pressure Switch (LOP) and a High Oil Temperature Switch.

DOWN:

Page 6.1-2

Section 6.2- ENGINE CONTROLLER BOARD

General

The Enalne Controller circuit board controls all

phases of engine operation, Including cranking, starting, running ana shutdown.

The circuit board interconnects with other com

ponents of the engine eiectricai system to turn

them on or off at the proper times.

The board is powered by fused 12 VDC battery

output, avaiiabie to the board via Wire 15.

Receptacle J3

wire 15 connects to Terminal J3. This Is fused

battery voltage. The Wire 15 circuit Is electrically hot at all times (provided the unit battery Is con nected).

Figure 2. Receptacle J1

WIRE

Delivers 12 VDC to Starter Contactor

Delivers 12 VDC to automatic choke

solenoid coll while cranking only.

18B

Interconnects CCG circuit board so

that board can stop engine In the event

of a generator fault (NOTE 1).

Not used on computer-controlled

When Wire 17 Is connected to ground

by holding Start-Run-Stop switch at

"START", cranking will occur.

ToncnsTT

while cranking only.

generator units.

Circuit Board Connections

The circuit board mounts a 15-pin receptacie

(J1). A 15-pin connector piug connects to this re ceptacle to Interconnect the board with other com

ponents and circuits. In addition, a single pin ter minal Is provided on the board for connection of

Wire 15 (J3) and a single pin terminal for Wire 14 (J2).

Receptacle J1

This 15-pln receptacle Is shown In Figure 2, along

with a chart that identifies each pin, wire and func tion.

Receptacle J2

Wire 14 connects to Terminal J2. This terminal and wire are electrically hot (12 volts DC) only when the engine is cranking or running. Battery voltage Is delivered to Terminal J2 when circuit board ac

tion energizes a board-mounted run relay while

cranking or running.

Wire 14 DC output is delivered to (a) the engine

fuel pump and (b) the engine Ignition system. If an

optional remote panel Is used. Wire 14 DC output

will turn on a "RUN" lamp on that panel.

Not used on computer-controlled

generator units.

Not used on computer-controlled

generator units.

Not used on computer-controlled

generator units.

AC signal from Stator battery charge

winding for starter cutout.

When grounded by Low Oil Pressure

or High oil Temperature switch, the

circuit board will stop engine.

Common frame ground.

Not used on Computer-controlled

generator units.

When Wire 17 Is connected to ground

by holding Start-Run-Stop switch at

"STOP^'i shutdown will occur.

Not used on computer-controlled

generator units.

NOTE 1:- See "AUTOMATIC SHUTDOWNS" In Section

1.2 (Page 1.2-5).

1 3 5 7 10 12 14

b P P □ □ □ □ o q q q q A A

Page 6.2-1

Section 6.2- ENGINE CONTROLLER BOARD

Page 6.2-2

Section 6.3- ENGINE CRANKING SYSTEM

Introduction

COMPONENTS:

The enqine cranking wstem Is shown schemat

ically in Figure 1, below. The system consists of the

following components:

n A 12 volts Battery. □ A Start-Run-Stop Switch (SW1). □ A Starter Contactor (SC), n A Starter Motor (SM). □ Engine Controller Circuit Board. □ Interconnecting wires.

OPERATION:

1. Holding the Start-Run-Stop switch (SW1) at

"START* connects Wire 17 from the Engine Con

troller board to frame ground.

a. Engine Controller board action energizes a crank relay on the board.

b. Closure of the crank relay’s contacts delivers 12 VDC to Wire 56 and to a Starter Contactor (SC). The Starter Contactor (SC) energizes and its con tacts close.

2. Closure of the the Starter Contractor (SC) con tacts delivers battery voltage to the Starter Motor

(SM). The Motor energizes and the engine is cranked.

and capable of delivering 360 cold-cranking amperes.

□ For prevailing ambient temperatures below 32*

F. (0* C.), use a battery rated 95 amp-hours and capable of delivering 450 cold-cranking am peres.

BATTERY CABLES:

Battery cables should be as short as possible and of adequate diameter. Cables that are too long or too small in diameter can result In voltage drop. The voltage drop between battery terminals and the connection point at generator should not exceed

0.121 volts per 100 amperes of cranking current.

The cables should be carefully selected based on

(a) cable length and (b) prevailing ambient temper atures. Generally, the longer the cable and the colder the ambient temperature, the larger the re quired cable size. The following chart applies:

CABLE LENGTH

Feet (Meters) CABLE SIZE 0 to 10(0 to 3) 2* 11 to 15(3.4-4.5 16 to 20 (4.5 to 6)

For warm weather use No. 2 cable up to 20 feet

000

The battery is generally supplied by the cus

tomer. Recommended is a battery that meets the following requirements:

□ Use a 12 VDC automotive type storage battery. □ For prevailing ambient temperatures above 32*

F. (0* C.), use a battery rated at 70 amp-hours

BATTERY CABLE CONNECTIONS:

1. Connect the cable from the large Starter Contac

tor (SC) lug to the battery post Indicated by a

POSITIVE, POS or (+).

*2:'Connect the cable from Its FRAME GROUND

connection to the battery post indicated by a NEG ATIVE, NEG or (-).

TESTING A BATTERY:

The best method of testing a battery Is with an

automotive type battery hydrometer. Some “Main tenance Free" batteries cannot be tested with a hydrometer.

Most batteries can be tested for both STATE OF

CHARGE and CONDITION as follows:

1. Test for State of Charge:a. Follow the hydrometer manufacturer's instruc

tions carefully. Test the specific gravity of the fluid in all battery cells.

b. If the hydrometer does not have a "Percentage of Charge" scale, compare the readings obtained

with the following:

SPECIRC GRAVITY

1.260

1.230

1.200

1.170

PERCENTAGE OF CHARGE

100%

75% 50% 25%

Page 6.3-1

Section 6.3- ENGINE CRANKING SYSTEM

Battery (Continued)

TESTING A BATTERY (CONT’D);

If the battery State of Charge Is less than 100%,

use an automotive type battery charger to recharge It to a 100% State of Charge.

2. Test for Condition:

a. If the difference In specific gravity between the highest and lowest reading cell is greater than

0.050 (50 points), the battery is nearing the end of Its userul life and should be replaced.

b. However, If the highest reading cell is less than

1.230, recharge thebattery and repeat the test.

Start-Run-Stop Switch (SW1)

Wires 17 and 18 connect to the two outer terminals of the switch. Wire 0 (ground) connects to the switch center terminal.

The switch can be tested

using a volt-ohm-milliam-

meter (VOM) as follows:

1. Set a volt-ohm-milliammeter (VOM) to read bat

tery voltage (12 VDC).

2. Connect the VOM test leads across the Wire 56 terminal of the Contactor and frame ground. The

meter should Indicate "zero" volts.

3. Hold the Start-Run-Stop switch at "START" and the VOM should read battery voltage and the Con tactor should energize. After reading the voltage,

release the switch. If battery voltage Is NOT indi

cated, a problem exists elsewehere in the circuit

4. Connect the VOM test leads across the Wire 16 terminal lug and frame ground.

a. Hold the Start-Run-Stop switch at “START". The Contactor should actuate and the meter should Indicate battery voltage.

b. If battery voltage Is not Indicated, replace the Starter Contactor.

c. If battery voltage Is Indicated but engine does

not crank, check the Starter Motor and its cable.

1. Set the VOM to Its" Rxl “ scale and zero the meter.

2. Connect the VOM test leads across the Wire 17 terminal and the center (Wire 0) terminals.

a. Hold the switch at "START" and the VOM

should indicate "continuity".

b. Hold switch at "STOP" and meter should read

"infinity".

3. Now, connect the meter test leads across the center and Wire 18 terminals.

a. With switch at “START" VOM should Indicate

"infinity".

b. With switch at "STOP", meter should read

"continuity".

Replace the switch If It is defective.

Starter Contactor

WIRE AND CABLE CONNECTIONS:

The red (positive) battery cable connects to one

of the starter contactor’s large terminal lugs. The

unit’s 15 amp fuse also attaches to this lug, via Wire

13.

The starter motor (SM) cable (16) attaches to the

second terminal lug.

Wire 56, from the engine controller circuit board, attaches to one of the small contactor terminals.

TESTING THE STARTER CONTACTOR:

To test the installed Starter Contactor, proceed

as follows:

The Starter Motor is a 12 volts negative ground

type. It Is capable of operating on heavy duty bat

tery Input at temperatures as low as -30 F. without any significant change in performance. Its pinion is a 10-tooth type having a 20’ pressure angle.

TESTING:

Connect the test leads of a VOM across the Starter Motor terminal and case. Hold the StartRun-Stop switch at "START". The VOM should read battery voltage and the Starter Motor should turn.

If VOM reads 12 volts DC and the Motor does not

turn, the Motor is probably defective. Remove the

Motor and test with a 12 volts DC power source.

Replace the Starter Motor if defective.

Page 6.3-2

Section 6.3- ENGINE CRANKING SYSTEM

Engine Controller Circuit Board

Refer to Section 6^.

Page 6.3-3

Section 6.3- ENGINE CRANKING SYSTEM

Page 6.3-4

Section 6.4- ENGINE IGNITION SYSTEM

Introduction

The engine ignition system consists of the fol*

lowing major components:

□ Ignition Cage Assembly. □ Ignition Sensor Assembly. □ Ignition Module (IM). □ Ignition Coll (1C). □ Spark Plug (SP1).

Ignition Cage Assembly

An IGNITION CAGE ASSEMBLY is factory In

stalled onto the permanent magnet rotor hub. Two

magnets are installed In the cage as shown In Figure 1 (50* apart), so that the north pole of one

magnet faces away from the cage outer periphery and the north pole of the other mag net faces toward the cage outer periphery. A special fixture Is used to install the cage onto the rotor hub so that the center line of the first magnet Is 68* away from the

Rotor Hub mounting hole as shown.

NOTE: Placement of the magnets on the Rotor Hub

at the exact position stated above results In an

Ignition timing of 29’ BTDC.

The Ignition Cage assembly cannot be replaced. The entire Rotor Hub must be replaced. Replacement Rotor Hubs will include a factory installed Ignition Cage assembly, and Magnetic Housing Assembly.

NOTE: Also refer to “Permanent Magnet Rotor" In Section 1^ (Page 1.2-1).

Figure 1. Ignition Cage Assembly

As the generator’s Permanent Magnet Rotor turns during operation, magnets on the Ignition Cage rotate past the Ignition Sensor to induce a timed low voltage pulse Into the Sensor. This volt age pulse Is delivered to an Ignition Module and serves as a timing pulse for the Module.

See Figure 3. The Sensor circuit board mounts solid state components which are sensitive to mag netism. Magnets In the Ignition Cage rotate past the Sensor, causing the base of a transistor to be

"pulsed". The transistor acts much like a "switch" or a set of "contact points". Pulsing the transistor base causes the "switch" to close and connect the

"OUT" lead to the "GND" lead. This triggers the Ignition Module to delivers primary Ignition current to the Ignition Coll at timed Intervals.

Figure 3. Ignition Sensor Schematic

Ignition Sensor

The Ignition Sensor is retained to the AC

enerator’s Stator Adapter by means of two M4.70 X 8mm screws and lockwashers. The Sensor

housing houses a circuit board. The entire housing

cavity is filled with potting material.

ignition Moduie

While cranking and running, battery voltage Is

delivered to the Ignition Module via Wire 14 from

the Engine Controller circuit board. The Module will deliver this battery voltage to the Ignition Coll

based on the "timing" signal it receives from the Ignition Sensor.

The Ignition Module Is retained In the generator

control panel by two capscrews.

Page 6.4-1

Section 6.4- ENGINE IGNITION SYSTEM

Ignition Module (Continued)

Ignition Coii

Primary Ignition voltage (12 VDC) Is delivered

from the Ignition Module to the Ignition Coll. The

Coil boosts the voltage and delivers the high volt

age to the engine Spark Plug.

Clean the Spark Plug and reset its gap to 0.030 inch (0.76mm) every 100 hours of operation. Clean by scraping or wire brushinq and washing with

commerciaf solvent. DO NOT blast clean the spark

plug.

Summary of Operation

See Figure 6. As the generator’s permanent mag

net rotor turns, magnets in the Rotor hub’s Ignition Cage rotate past an Ignition Sensor at fixeci inter vals.

Battery voltage is delivered to an Ignition Module

during cranking and running, via Wire 14. From the

Ignition Module, battery voltag^e is also delivered to

the Ignition Sensor via the RED (+) lead. The Igni tion Sensor acts as a "trigger" mechanism, causing

the Ignition Module to deliver its output to the

Ignition Coll at timed intervals. Current flows through the primary coll of the Ignition Coil and

then collapses to Induce a high voltage Into the

Ignition Coil’s secondary coil. This high voltage (about 25,000 volts) is delivered to the Spark Plug to fire the spark plug gap.

Components encapsulated in the Ignition Mod

ule provide an automatic spark advance. At crank

ing speeds, ignition will occur at about 15'-18*

BTDC. At higher speeds. Ignition can occur up to 29* BTDC.

Spark Piug

The Spark Plug on GN-190 and GN-220 engines

is a Champion RC12YC (or equivalent).

Page 6.4-2

Ignition Timing

Ignition timing is fixed and non-adjustable.

Testing the System

GENERAL:

Solid state components Inside the Ignition Sen

sor, Ignition Module and Ignition Coil are not acces sible and cannot be serviced. If any of these com ponents is defective, the entire component must be replaced. The system does not include an arma ture and there Is no air gap to adjust, or breaker points to adjust or replace.

________________

Section 6.4- ENGINE IGNITION SYSTEM

TESTING FOR SPARK:

To test the Ignition system, a suitable spark tes ter may be used. Such spark testers are commer cially available. Test the system as follows:

1. Disconnect the high tension lead from the spark

plug.

2. Attach the spark plug

high tension lead to the

spark tester terminal.

3. Connect the spark tester clamp to the engine cylin der head.

4. Crank the engine rapidly. Engine must be turning at 350 rpm or more. If spark

Jumps the tester gap, you

may assume the ignition system is operating satis

factorily.

If sparking across the tester gap does-NOT occur, go to XHECK POWER SUPPLY".

CHECKING ENGINE MISS:

To determine if an engine miss is Ignition related, connect the spark tester In series with the spark plug’s high tension lead and the spark plug. Then, start the engine. If spark jumps the tester gap at regular intervals but the engine miss continues, the problem is In the spark plug or in the fuel system.

CHECK POWER SUPPLY:

When the engine is being cranked, battery volt

age should be available from the Engine Controller circuit board to a 4-termlnal connector via Wire 14.

From the 4-termlnal connector, battery voltage

should be available to the Ignition Module via Wire

14 (RED wire). And battery voltage should be avail

able from the Ignition Module to the Ignition Sensor via a RED wire. If this 12 VDC power supply is not available, the ignition system will not function. To check the power supply, proceed as follows using a volt-ohm-milliammeter (VOM):

1. Gain access to the control panel interior.

2. In the panel, locate the 3-pin connector that Interconnects the Ignition Module and the ignition Sensor.

3. Press down on the connector lock tang and disconnect the two connector halves.

NOTE: A single large black lead carries the three leads from the Ignition Sensor to the 3-pln MALE connector. The three leads from the Ignition Mod

ule (brown, green and red) attach to the 3-pln FE

MALE connector.

4. Set the VOM to a scale that will allow battery volt age to be read (about 12 volts DC).

5. Connect the meter test leads across the center FE MALE pin (RED wire) and frame ground.

6. Hold the Start-Run-Stop switch at "START". The meter should read battery

voltage.

If battery voltage Is NOT indicated, go to Step 7.

If battery voltage IS Indicated, go to "CHECK IGNI

TION SENSOR^..

7. Now locate the 4-termi nal connector in the panel. Connect the VOM test leads across the terminal

and frame ground. Crank the engine and the VOM should read battery volt age.

a. If battery voltage is indicated now but was NOT Indicated In Step 6,

test Wire 14 (RED) be tween the 4-terminal

connector and the Igni

tion Module. If wire is

bad, repair or replace as necessary.

b. If battery voltage Is NOT Indicated In Step 7, test Wire 14 between the 4-terminal connector and the Engine Controller circuit board. Repair or replace as necessary.

CHECK IGNITION SENSOR:

1. In the 3-pln connector plug half from the Ignition Module, locate FEMALE Pin 1 to which the BROWN wire connects.

2. Connect a jumper wire from FEMALE Pin 1 (BROWN wire) to frame ground.

3. Connect the Spark Plug high tension lead to a spark tester (Figure 8) and the spark tester clamp to ground.

Page 6.4-3

Section 6.4- ENGINE IGNITION SYSTEM

Testing the System (Continued)

CHECK IGNITION SENSOR (CONT’D);

4. Crank the engine and observe the spark tester for sparking.

IGNITION SENSOR" and under "TESTING IGNITION COIL". If these components tested good, replace the Ignition Module.

If sparking occurs with the BROWN wire grounded but did NOT occur under "TESTING

FOR SPARK", the Ignition

Sensor is probabiy defec tive and shouid be repiaced.

NOTE: The Ignition Sensor Is mounted to the

generator's Stator Adapter. To replace the Sensor,

disassembly of the generator and removal of the Stator will be necessary.

If sparking does NOT occur with the BROWN wire grounded and did NOT occur under "TESTING FOR SPARK", either the Ignition Module or the Ignition Coil is defective. Go to "TESTING IGNITION COIL".

TESTING IGNITION COIL:

The Ignition Coil is housed In the generator con

trol panel. To test the coil, proceed as follows:

1. Unplug the two halves of the 2-pin connector plug from the Ignition Coil. The red and white wires are the primary coil leads.

2. To read PRIMARY coil resistance:

a. Set a volt-ohm-milllammeter (VOM) to its "Rx1"

scale and zero the meter.

b. Connect the VOM test leads across the two

male pins of the 2-pin connector. Primary coil

resistance should be about 0.5 to 1.5 ohms.

3. To read SECONDARY coil resistance:

a. Set the VOM to its "Rxl0,000" or "Rx1K" scale and zero the meter.

b. Unplug the high tension lead from the Spark

Plug.

c. Connect one VOM test lead to the white wire connector pin.

d. Connect the other VOM test lead into the Spark

Plug lead rubber boot so it contacts the lead’s

metal terminal end. The VOM should read ap

proximately 16,000-17,000 ohms (16.0-17.0 k-

Ohms).

Figure 13. Testing Ignition Coll

16,000-17,000 OHMS

Replace the Ignition Coil if defective. If the Ignition

Coll tested good, go to "TESTING IGNITION MOD

ULE".

TESTING IGNITION MODULE:

If a problem was indicated under "TESTING FOR SPARK", you should have completed the tests under "CHECK POWER SUPPLY", under "CHECK

Page 6.4-4

Section 6.5- ENGINE PROTECTIVE DEVICES

The engine mounts an Oil Pressure Switch (LOP)

General

and an Oil Temperature Switch (НТО). These two switches, In conjunction with the^gine Controller circuit board, protect the engine against (a) low oil pressure and (b) high oil temperature.

The engine protective circuit is shown In Rgure

Oil Pressure Switch

DESCRIPTION:

The Oil Pressure Switch has normally-closed contacts which are held open by engine oil pressure during cranking and running. Should oil pressure drop below approximately 5 psi, the switch contacts will dose to complete the Wire 85 circuit to ground. Engine Controller circuit board action will then de-energize the Wire 14 circuit and

the engine will shut down.

The Engine Controller circuit board provides a

time delay to allow oil pressure to build during

startup, to prevent premature shutdown.

NOTE: Early production NP40G units wore equipped with a Low Oil Switch rated 10 psi (Part No. ¿0108). Later production units are now equipped with a Low Oii Switch rated 5 psi (Part No. Т/бЕЛ. Units equipped with the 10psi Switch must be retrofitted with the new 5 psi Switch (Part No.

77667). .

Figure 1. Engine Protective Circuit

BCCB - BtraiNB CONTROL CIRCUIT BORRO НТО ■ HIOH Olb TSHP. SWITCH LOP ■ LOW OIL PRBSSURB SWITCH

ECCB

НТО

O-p-o—< I

LOP

A. Schematic

’A ^

TESTING THE SWITCH:

Use a voit-ohm-milliammeter (VOM) to test the oil pressure switch. Connect the VOM test leads

across the switch terminal and the switch body. With the engine shut down, the meter should read “continuity” (a very small resistance is acceptable). With engine running, the meter should read “infinity”.

Oil Temperature Switch

DESCRIPTION:

This thermostatic switch has normally-open contacts. Should engine oil temperature exceed a preset safe value (about 293^ F.), the switch

contacts will close. On closure of the Switch contacts, the Wire 85 circuit will be connected to frame ground. Engine shutdown will then occur.

NOTE: Eariy production NP40G units were equipped with an Oil Temperature Switch rated

265^ F. That Oil Temperature Switch has been

replaced on later production units by the 293^ F. Switch (Part No. 94090). Early units having the

26S^ F. Switch may be subject to overtemperature shutdown and should be retrofitted with the new 293« F. Switch.

Page 6.5-1

Section 6.5- ENGINE PROTECTIVE DEVICES

Oil Temperature Switch

(Continued)

NOTE: The CCG circuit board also has automatic engine shutdown capability. The circuit board will shut the engine down automatically on occurence of (a) over-voltage, (bj under-voltage, (c) over speed, (di zero current failure, (e) converter failure, or (ef) micro-processor failure, see Section 1.2.

TESTING;

See Figure 3. Remove the switch and piace its sensing tip into oii. Place a thermometer into the oil. Connect the test leads of a VOM across the

switch terminals. The meter should read "Infinity''.

Heat the oil. When oil temperature reaches

approximately 287<-296a F. (142a-147a C.), the

meter should read "continuity" (a small resistance Is acceptable).

NOTE: The above procedure yjplles to OII Temperature Switch Part No. 94090, rated 293^ F. (14S‘ C.). Some early production units were equipped with a 265‘ F. switch which caused

premature high temperature shutdowns. The 265^

F. switch should be removed and replaced with the Part No. 94090 switch.

Page 6.5-2

Revised- 02/07/95

Section 6.6- OPTIONAL REMOTE PANEL

General

An optional remote-mounted Start-Stop panel is available. This panel will permit the generator to be started and stopped from some convenient remote

location In the recreational vehicle.

Remote Panel Cables

The generator Is equipped with a 4-pin receptacle for connection of the remote panel. Cables are available which mate with the receptacle and Inter connect the generator with the remote panel.

□ Cable Model 9045 is a 10 foot long, 4-wlre cable. □ Cable Model 9046 Is a 30 foot long, 4-wire cable.

Figure 1. Remote Panel Receptacle

WIRE #18 (STOP)

WIRE #0 (GROUND)

WIRE #14 (ENGINE RUN SIGNAL)

WIRE #17 (CRANK)

MODEL 9043:

The Model 9043 remote panel mounts a rocker

type Start-Run-Stop switch, a "GEN. RUN" lamp and an hourmeter.

The "GEN. RUN" lamp will turn on when the

engine Is running. It is turned on by Wire 14 power.

The Hourmeter provides a continuous Indication of oenerator operating hours in hours and tenths of hours. It can be used in conjunction with the required periodic maintenance on the unit.

Figure 3. Model 9043 Remote Panel

^GENERAC R.V. GENERATOR °

GEN.

STOP

RUN

START

TOTAL HOURS

Wiring Connections

wiring connections for the remote panel are

shown in Figure 4.

Description

MODEL 9042:

The Model 9042 remote panel mounts a rocker

type Start-Run-Stop switch and a "GEN. RUN" ad visory lamp. The lamp Is turned on by Wire 14 current when the generator Is running.

Figure 2. Model 9042 Remote Panel

Page 6.6-1

Section 6.6- OPTIONAL REMOTE PANEL

Page 6.6-2

Part 7

TROUBLE

SHOOTING

COMPUTER

CONTROLLED

VARIABLE SPEED RV

GENERATORS

Series NP-30G and NP-40G

SECTION

7.1

7.2

TITLE

GENERATOR & SPEED CONTROL

ENGINE DC CONTROL SYSTEM

Generac Power Systems NP-40G User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

SAFETY

NOTICE TO USERS OF THIS MANUAL

REPLACEMENT PARTS

SERVICE

MANUAL

Magnetism

Electromagnetic Fields

Electromagnetic induction

Alternating Current

Alternating Current (Continued)

Electrical Units

Ohm’s Law

Reactance in AC Circuits

Why Variable

Speed Control?

Introduction

Upper Fan Housing

Upper Cooling Fan

Permanent Magnet Rotor

Rotor Hub

Stator Retaining Ring

Stator Assembly

Stator Adapter

Lower Fan & Flywheel

Engine

Stepper Motor

The Genistor

The CCG Circuit Board

The CCG

Dirt and Moisture

Insuiation Resistance Testers

Stator Leads

Preparation for Tests

Test Aii Stator Windings to Ground

Test for Shorts Between Windings

Results of Tests

Cleaning the Generator

Drying the Generator

Introduction

Stator Assembly

Genistor

Testing the Battery Charge Circuit

Testing the CCG Circuit Board

Construction

Components

General

Parts List for Exploded View of Sheet Metal

Introduction

4-Cycle Engine Theory

Recommended Fuels

Recommended Engine Oil

Storage Instructions

Engine Tuneup

Exploded View of Engine Long Block

Valve Components Removal

Valve Service

Valve Service (Continued)

Valve Components Installation

Adjusting Valve Clearance

Rocker Arm Cover installation

Section 2.3- PISTON, RINGS, CONNECTING ROD

Oversize Piston & Rings

Prior to Removai

Removai

Piston

Section 2,3- PISTON, RINGS, CONNECTING ROD

Piston (Continued)

Piston Rings

Connecting Rod

Assembly and Installation

Cylinder Service (Continued)

General

Crankcase Cover Removal

Camshaft Removal

Crankshaft Removal

Camshaft Inspection