Guardian Technologies 4451, 4582, 4583, 5308, 4986 User Manual

PORTABLES

MODELS:

4451 & 4986 (12,500 Watt)
4582 & 4987 (15,000 Watt)
4583 (17,500 Watt)

5209 (15,000 Watt)
5308 (17,500 Watt)

DIAGNOSTIC
REPAIR MANUAL

ULTRA SOURCE PORTABLE GENERATOR

www.guardiangenerators.com

SAFETY

Throughout this publication, "DANGER!" and "CAUTION!" 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, could 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 themselves 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.

Table of Contents

SAFETY .................. INSIDE FRONT COVER (IFC)

NOTICE TO USERS OF THIS MANUAL ..............................IFC

REPLACEMENT PARTS .....................................................IFC

TABLE OF CONTENTS ...................................... 1-2

SECTION 1:

GENERATOR FUNDAMENTALS ....................... 3-5

MAGNETISM ..................................................................... 3

ELECTROMAGNETIC FIELDS ..............................................

ELECTROMAGNETIC INDUCTION ......................................

A SIMPLE AC GENERATOR ................................................

A MORE SOPHISTICATED AC GENERATOR .........................

SECTION 2:

MEASURING ELECTRICITY ............................. 6-8

METERS .......................................................................... 6

THE VOM ........................................................................

MEASURING AC VOLTAGE ..............................................

MEASURING DC VOLTAGE ..............................................

MEASURING AC FREQUENCY .........................................

MEASURING CURRENT ....................................................

MEASURING RESISTANCE ................................................

ELECTRICAL UNITS ..........................................................

OHM'S LAW

.................................................................... 8

SECTION 3:

DESCRIPTION AND COMPONENTS ............. 9-15

INTRODUCTION .............................................................. 9

ENGINE-GENERATOR DRIVE SYSTEM ...............................

THE AC GENERATOR .......................................................

ROTOR ASSEMBLY ..........................................................

STATOR ASSEMBLY

BRUSH HOLDER AND BRUSHES .....................................

OTHER AC GENERATOR COMPONENTS ........................

EXCITATION CIRCUIT BREAKER

VOLTAGE REGULATOR ..............................................

ADJUSTMENT PROCEDURE .......................................

CIRCUIT BREAKERS ................................................... 12

ROTOR RESIDUAL MAGNETISM ..................................... 12

FIELD BOOST CIRCUIT ...................................................

OPERATION ...................................................................

STARTUP ................................................................... 12

ON-SPEED OPERATION .............................................. 12

FIELD EXCITATION .....................................................

AC POWER WINDING OUTPUT ..................................

BATTERY CHARGE WINDING OUTPUT .......................

10 AMP BATTERY CHARGE WINDING OUTPUT

INSULATION RESISTANCE ..............................................

THE MEGOHMMETER ...................................................

GENERAL ..................................................................

TESTING STATOR INSULATION ...................................

TESTING ROTOR INSULATION ....................................

HI-POT TESTER .......................................................... 13

........................................................ 10

10
10

.................................. 10

11
11

12
12

12
12
12

.......... 12

13
13

13
13
13

STATOR INSULATION RESISTANCE TEST ..........................

GENERAL ..................................................................

TESTING ALL STATOR WINDINGS TO GROUND ..........

TEST BETWEEN WINDINGS: .......................................

ROTOR INSULATION RESISTANCE TEST ..........................

CLEANING THE GENERATOR .........................................

DRYING THE GENERATOR .............................................

13
13
14
14

15
15
15

SECTION 4:

ENGINE DC CONTROL SYSTEM .................. 16-27

3
3
4
4

6
6
6
6
7
7
8

PRINTED CIRCUIT BOARD .............................................. 16

GENERAL ..................................................................

CIRCUIT BOARD CONNECTIONS ...............................

DIP SWITCH POSITIONS .............................................

BATTERY .......................................................................

RECOMMENDED BATTERY ........................................

CONTROL PANEL COMPONENT IDENTIFICATION ......

OPERATIONAL ANALYSIS ..........................................

CIRCUIT CONDITION - REST ......................................

CIRCUIT CONDITION - START ....................................

CIRCUIT CONDITION - RUN .......................................

CIRCUIT CONDITION - STOP ...................................... 26

FAULT SHUTDOWN ...................................................

16
16
16

16

16
17-18
20-27

20

22

24

27

SECTION 5:

TROUBLESHOOTING FLOWCHARTS .......... 28-36

INTRODUCTION ............................................................ 28

IF PROBLEM INVOLVES AC OUTPUT

9
9
9

PROBLEM 1 -

VOLTAGE & FREQUENCY ARE BOTH HIGH OR LOW ..

PROBLEM 2 -

GENERATOR PRODUCES ZERO VOLTAGE

OR RESIDUAL VOLTAGE (2-12 VAC) ......................

PROBLEM 3 -

EXCESSIVE VOLTAGE/FREQUENCY

DROOP WHEN LOAD IS APPLIED ...............................

PROBLEM 4 -

NO BATTERY CHARGE OUTPUT .................................

PROBLEM 5 -

NO 10 AMP BATTERY CHARGE OUTPUT ...................

PROBLEM 6 -

ENGINE WILL NOT CRANK ........................................

PROBLEM 7 -

ENGINE CRANKS BUT WILL NOT START .....................

PROBLEM 8 -

ENGINE STARTS HARD AND RUNS ROUGH ................

PROBLEM 9 -

ENGINE STARTS THEN SHUTS DOWN ........................

PROBLEM 10 -

10 AMP FUSE (F1) BLOWING .....................................

PROBLEM 11 -

UNIT OVERSPEEDS ....................................................

PROBLEM 12 -

IDLE CONTROL “RPM DOES NOT DECREASE” ...........

PROBLEM 13 -

IDLE CONTROL “RPM DOES NOT INCREASE

WHEN LOAD IS APPLIED” ..........................................

PROBLEM 14 -

ENGINE “HUNTS” / ERRATIC IDLE ..............................

............................... 28

28

29-30

30

31

31

32

33

34

34

35

36

36

36

36

Page 1

Table of Contents

SECTION 6:

DIAGNOSTIC TESTS ...................................... 37-65

INTRODUCTION .............................................................. 37

TEST 1 - CHECK NO-LOAD VOLTAGE AND FREQUENCY ..

TEST 2 - CHECK MAIN CIRCUIT BREAKER ........................

TEST 3- TEST EXCITATION CIRCUIT BREAKER ...................

TEST 4 - FIXED EXCITATION TEST/ROTOR AMP DRAW .....

TEST 5 - CHECK STEPPER MOTOR CONTROL ................... 40

TEST 6 - WIRE CONTINUITY .............................................

TEST 7 - CHECK FIELD BOOST .........................................

TEST 8 - DIODE/RESISTOR ................................................

TEST 9 - TEST STATOR ..................................................... 43

TEST 10 - SENSING LEADS ...............................................

TEST 11 - EXCITATION WIRING ........................................

TEST 12 - CHECK BRUSH LEADS ......................................

TEST 13 - CHECK BRUSHES & SLIP RINGS ........................

TEST 14 - CHECK ROTOR ASSEMBLY ...............................

TEST 15 - CHECK LOAD VOLTAGE & FREQUENCY ...........

TEST 16 - CHECK LOAD WATTS & AMPERAGE ................

TEST 17 - CHECK BATTERY CHARGE OUTPUT .................

TEST 18 - CHECK 10 AMP BATTERY CHARGE OUTPUT ....

TEST 19 - CHECK BATTERY CHARGE RECTIFIER ...............

TEST 20 - CHECK 10 AMP CIRCUIT BREAKER ..................

TEST 21- CHECK 10 AMP FUSE .......................................

TEST 22- CHECK BATTERY & CABLES ..............................

TEST 23- CHECK VOLTAGE AT STARTER CONTACTOR .....

TEST 24 - CHECK STARTER CONTACTOR .........................

TEST 25 - CHECK STARTER MOTOR .................................

CONDITIONS AFFECTING STARTER MOTOR

PERFORMANCE: ..........................................................

CHECKING THE PINION: ..............................................

TOOLS FOR STARTER PERFORMANCE TEST: ................. 50

MEASURING CURRENT: ...............................................

TACHOMETER: ............................................................

TEST BRACKET: ...........................................................

REMOVE STARTER MOTOR: .........................................

TESTING STARTER MOTOR: .........................................

TEST 26 - TEST STARTER CONTACTOR RELAY (SCR) .........

TEST 27- CHECK START-RUN-STOP SWITCH ...................

TEST 28- CHECK START-RUN-STOP (SW1) WIRING ...........

TEST 29 - CHECK IGNITION SPARK ..................................

TEST 30 - CHECK SPARK PLUGS ......................................

TEST 31 - REMOVE WIRE 18 / SHUTDOWN LEAD ............

TEST 32 - TEST START STOP RELAY ..................................

TEST 33- TEST WIRE 167 .................................................

TEST 34 - TEST START STOP RELAY WIRING .....................

TEST 35 - CHECK AND ADJUST IGNITION MAGNETOS ....

TEST 36: TEST FUEL SHUTOFF SOLENOID .........................

TEST 37: TEST FUEL SHUTOFF SOLENOID VOLTAGE .........

TEST 38: CHECK FUEL PUMP ........................................... 57

37
37
38
38

41
41
42

44
45
45
45
46
46
46
47
47
47
48
48
48
49
49
49

49
50

50
50
51
51
51

51
52
52
53
53
54
54
55
56
56
57
57

TEST 39 - CHECK CARBURETION .....................................

TEST 40 - VALVE ADJUSTMENT ........................................

TEST 41 - CHECK ENGINE / CYLINDER LEAK

DOWN TEST / COMPRESSION TEST .................................

TEST 42 - CHECK OIL PRESSURE SWITCH AND WIRE 86 ..

TEST 43: CHECK START STOP RELAY (SSR) .......................

TEST 44: TEST STARTER CONTACTOR RELAY (SCR) ..........

TEST 45: CHECK WIRE 15 CIRCUIT ..................................

TEST 46: CHECK WIRE 14 CIRCUIT ..................................

TEST 47: CHECK FUEL SHUTOFF SOLENOID .....................

TEST 48: CHECK HOURMETER ........................................ 62

TEST 49: CHECK WIRE 15B .............................................

TEST 50: CHECK WIRE 167 .............................................

TEST 51: CHECK WIRES 11S & 44S ..................................

TEST 52: CHECK IDLE CONTROL SWITCH (SW2) ..............

TEST 53: CHECK IDLE CONTROL WIRING ........................

TEST 54: CHECK IDLE CONTROL TRANSFORMERS ...........

TEST 55: CHECK TR1 & TR2 WIRING ...............................

TEST 56: CHOKE TEST ...................................................

58
58

59
60
60
61
61
61
61

62
62
62
63
63
64
64

65

SECTION 7:

DISASSEMBLY AND EXPLODED VIEWS ..... 66-71

MAJOR DISASSEMBLY ..................................................... 66

GENERATOR – FIGURE A ................................................

FRAME, HANDLE & WHEELS – FIGURE B .........................

68
70

SECTION 8:

ELECTRICAL DATA ......................................... 72-79

WIRING DIAGRAM 12.5 & 15 KW (UNITS WITHOUT

HOURMETER) – DRAWING NO. 0E0228 ..........................

ELECTRICAL SCHEMATIC 12.5 & 15 KW (UNITS

WITHOUT HOURMETER) – DRAWING NO. 0E0229-A .......

WIRING DIAGRAM 12.5 & 15 KW
(UNITS WITH HOURMETER) – DRAWING NO. 0D4609-D ..

ELECTRICAL SCHEMATIC 12.5 & 15 KW (UNITS WITH

HOURMETER) – DRAWING NO. 0D6297-A ......................

WIRING DIAGRAM 17.5 KW UNITS –

DRAWING NO. 0G0731 ..................................................

ELECTRICAL SCHEMATIC 17.5 KW UNITS –

DRAWING NO. 0G0733 ..................................................

WIRING DIAGRAM, 17.5 KW MANUAL

TRANSFER SWITCH – DRAWING NO. 0G1065 ................

INTERCONECTION DRAWING – 17.5 KW GENERATOR ....

72

74

76

78

80

82

83
84

SECTION 9:

SPECIFICATIONS & CHARTS ....................... 86-87

GENERATOR SPECIFICATIONS .......................................... 86

ENGINE

SPECIFICATIONS ................................................. 86

ENGINE SPEEDS AND VOLTAGE SPECIFICATIONS .............

TORQUE SPECIFICATIONS ................................................

TRIM TORQUE SPECIFICATIONS .......................................

86
87
87

Page 2

Section 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, motors and numerous other devices that uti­lize magnetism to produce and use electrical energy.

See Figure 1-1. The space surrounding a magnet is
permeated by magnetic lines of force called “flux”.
These lines of force are concentrated at the magnet's
north and south poles. They are directed away from
the magnet at its nor th pole, travel in a loop and
re-enter the magnet at its south pole. The lines of
force form definite patterns 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 of force are effective is
called a “magnetic field”.

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

Figure 1-1. – Magnetic Lines of Force

ELECTROMAGNETIC FIELDS

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.

Figure 1-2. – The Right Hand Rule

ELECTROMAGNETIC INDUCTION

An electromotive force (EMF) or voltage can be pro­duced 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 1-3, below, illustrates a simple revolving field
generator. The permanent magnet (Rotor) is rotated
so that its lines of magnetic force cut across a coil 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.

All 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:

• The greater the current flow through the conductor,
the stronger the magnetic field around the conductor.

• The increase in the number of lines of force is
directly proportional to the increase in current flow
and the field is distributed along the full length of
the conductor.

• 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.

-

Figure 1-3. – A Simple Revolving Field Generator

Page 3

Section 1

S

TATOR

ROT

OR

MAGNETIC FIEL

D

CURRENT

VOLTAGE

ONE CYCLE

0

180

360

(+)

(-)

S

TAT

OR

BRUSHE

S

120

V

120

V

SLIP

RIN

GS

OU

TP

U

T

CU

RRENT

S

TAT

OR

240

V

GENERATOR FUNDAMENTALS

A SIMPLE AC GENERATOR

Figure 1-4 shows a very simple AC Generator. The
generator consists of a rotating magnetic field called a
ROTOR and a stationary coil of wire called a STATOR.
The ROTOR is a permanent magnet which consists
of a SOUTH magnetic pole and a NORTH magnetic
pole.

As the MOTOR turns, its magnetic field cuts across
the stationar y STATOR. A voltage is induced Into
the STATOR windings. When the magnet's NORTH
pole passes the STATOR, current flows in one direc­tion. Current flows in the opposite direction when the
magnet's SOUTH pole passes the STATOR. This con­stant reversal of current flow results in an alternating
current (AC) waveform that can be diagrammed as
shown in Figure 1-5.

The ROTOR may be a 2-pole type having a single
NORTH and a single SOUTH magnetic pole. Some
ROTORS are 4-pole type with two SOUTH and two
NORTH magnetic poles. The following apply:

1. The 2-pole ROTOR must be turned at 3600 rpm to produce

an AC frequency of 60 Hertz, or at 3000 rpm to deliver an AC

frequency of 50 Hertz.

2. The 4-pole ROTOR must operate at 1800 rpm to deliver a 60

Hertz AC frequency or at 1500 rpm to deliver a 50 Hertz AC

frequency.

Figure 1-5. – Alternating Current Sine Wave

A MORE SOPHISTICATED AC GENERATOR

Figure 1-6 represents a more sophisticated generator.
A regulated direct current is delivered into the ROTOR
windings via carbon BRUSHES AND SLIP RINGS.
This results in the creation of a regulated magnetic
field around the ROTOR. As a result, a regulated volt­age is induced into the STATOR. Regulated current
delivered to the ROTOR is called “EXCITATION” cur­rent.

Page 4

Figure 1-4. – A Simple AC Generator

Figure 1-6. – A More Sophisticated Generator

See Figure 1-7 (next page). The revolving magnet­ic field (ROTOR) is driven by the engine at a con­stant speed. This constant speed is maintained by a
mechanical engine governor. Units with a 2-pole rotor
require an operating speed of 3600 rpm to deliver a
60 Hertz AC output.

Generator operation may be described briefly as fol­lows:

1. Some “residual” magnetism is normally present in the Rotor

and is sufficient to induce approximately 7 to 12 volts AC Into

the STATOR's AC power windings.

Section 1

ENGINE ­DIRECT DRIVE

CB2

BCR2

BCR1

BCR1 & BCR2 = BATTERY CHARGE RECTIFIER

FIELD BOOST FROM
START/STOP RELAY (SSR)

CB1

CB2 = EXCITATION CIRCUIT BREAKER

12V DC

OUTLET

10A STATOR

BATTERY CHARGE

WINDING

STATOR

BATTERY CHARGE

WINDING

STATOR

DPE

WINDING

STATOR
POWER

WINDING

STATOR
POWER

WINDING

ROTOR

VOLTAGE

REGULATOR

GENERATOR FUNDAMENTALS

Figure 1-7. – Generator Operating Diagram

2. During startup, printed circuit board action controls the START/

STOP RELAY to deliver battery voltage to the ROTOR, via the

brushes and slip rings.

a. The battery voltage is called “Field Boost”.
b. Flow of direct current through the ROTOR

increases the strength of the magnetic field
above that of “residual” magnetism alone.

3. “Residual” plus “Field Boost” magnetism induces a voltage into

the Stator excitation (DPE), battery charge and AC Power wind-

ings.

4. Excitation winding unregulated AC output is delivered to an

electronic Voltage Regulator, via an Excitation Circuit Breaker.

a. A “Reference” voltage has been preset into

the Voltage Regulator.

b. An “Actual” (“sensing”) voltage is delivered

to the Voltage Regulator via sensing leads
from the Stator AC power windings.

c. The Regulator “compares” the actual (sens-

ing) voltage to its pre-set reference voltage.

(1) If the actual (sensing) voltage is great-

er than the pre-set reference voltage, the
Regulator will decrease the regulated cur­rent flow to the Rotor.

(2) If the actual (sensing) voltage is less

than the pre-set reference voltage, the
Regulator will increase the regulated current
flow to the Rotor.

(3) In the manner described, the Regulator

maintains an actual (sensing) voltage that is
equal to the pre-set reference voltage.

NOTE: The Voltage Regulator also changes the
Stator excitation windings alternating current (AC)
output to direct current (DC).

5. When an electrical load is connected across the Stator power

windings, the circuit is completed and an electrical current will

flow.

6. The Rotor's magnetic field also induces a voltage into the

Stator battery charge windings.

a. Battery charge winding AC output is deliv

ered to the battery charge rectifiers (BCR)
which changes the AC to direct current
(DC).

b. The rectified DC is then delivered to the

units battery and battery charge outlet, to
maintain the battery in a charged state.

-

Page 5

Section 2
MEASURING ELECTRICITY

METERS

Devices used to measure electrical properties are
called meters. Meters are available that allow one
to measure (a) AC voltage, (b) DC voltage, (c) AC
frequency, and (d) resistance in ohms. The following
apply:

• To measure AC voltage, use an AC voltmeter.

• To measure DC voltage, use a DC voltmeter.

• Use a frequency meter to measure AC frequency in
“Hertz” or “cycles per second”..

• Use an ohmmeter to read circuit resistance, in
“ohms”.

THE VOM

A meter that will permit both voltage and resistance to
be read is the “volt-ohm-milliammeter” or “VOM”.

Some VOMs are of the “analog” type (not shown).
These meters display the value being measured by
physically deflecting a needle across a graduated
scale. The scale used must be interpreted by the user.

“Digital” VOM's (Figure 2-1) are also available and
are generally very accurate. Digital meters display the
measured values directly by converting the values to
numbers.

NOTE: Standard AC voltmeters react to the
AVERAGE value of alternating current. When
working with AC, the effective value is used. For
that reason a different scale is used on an AC
voltmeter. The scale is marked with the effective
or “rms” value even though the meter actually
reacts to the average value. That is why the AC
voltmeter will give an incorrect reading if used to
measure direct current (DC).

MEASURING AC VOLTAGE

An accurate AC voltmeter or a VOM may be used to
read the generator's AC output voltage. The following
apply:

1. Always read the generator's AC output voltage only at the unit's

rated operating speed and AC frequency.

2. The generator's Voltage Regulator can be adjusted for correct

output voltage only while the unit is operating at its correct

rated speed and frequency.

3. Only an AC voltmeter may be used to measure AC voltage. DO

NOT USE A DC VOLTMETER FOR THIS PURPOSE.

DANGER!: GENERATORS PRODUCE HIGH

*

AND DANGEROUS VOLTAGES. CONTACT
WITH HIGH VOLTAGE TERMINALS WILL
RESULT IN DANGEROUS AND POSSIBLY
LETHAL ELECTRICAL SHOCK.

MEASURING DC VOLTAGE

A DC voltmeter or a VOM may be used to measure
DC voltages. Always observe the following rules:

1. Always observe correct DC polarity.

a. Some VOM's may be equipped with a polar-

ity switch.

b. On meters that do n ot have a polar-

ity switch, DC polarity must be reversed by
reversing the test leads.

2. Before reading a DC voltage, always set the meter to a higher

voltage scale than the anticipated reading. If in doubt, start at

the highest scale and adjust the scale downward until correct

readings are obtained.

Page 6

Figure 2-1. – Digital VOM

3. The design of some meters is based on the “current flow”

theory while others are based on the “electron flow” theory.

a. The “current flow” theory assumes that

direct current flows from the positive (+) to
the negative (-).

b. The “electron flow” theory assumes that cur-

rent flows from negative (-) to positive (+).

NOTE: When testing generators, the “current flow”
theory is applied. That is, current is assumed to
flow from positive (+) to negative (-).

MEASURING AC FREQUENCY

The generator's AC output frequency is proportional
to Rotor speed. Generators equipped with a 2-pole
Rotor must operate at 3600 rpm to supply a frequency
of 60 Hertz. Units with 4-pole Rotor must run at 1800
rpm to deliver 60 Hertz.

Correct engine and Rotor speed is maintained by an

Section 2

1.00 A

BATTERY

+-

RELAY

MEASURING ELECTRICITY

engine speed governor. For models rated 60 Hertz,
the governor is generally set to maintain a no-load fre­quency of about 62 Hertz with a corresponding output
voltage of about 124 volts AC line-to-neutral. Engine
speed and frequency at no-load are set slightly high
to prevent excessive rpm and frequency droop under
heavy electrical loading.

MEASURING CURRENT

CLAMP-ON:
To read the current flow, in AMPERES, a clamp-on

ammeter may be used. This type of meter indicates
current flow through a conductor by measuring the
strength of the magnetic field around that conductor.
The meter consists essentially of a current trans­former with a split core and a rectifier type instrument
connected to the secondary. The primary of the cur­rent transformer is the conductor through which the
current to be measured flows. The split core allows
the instrument to be clamped around the conductor
without disconnecting it.

Current flowing through a conductor may be mea­sured safely and easily. A line-splitter can be used
to measure current in a cord without separating the
conductors.

NOTE: If the physical size of the conductor or
ammeter capacity does not permit all lines to be
measured simultaneously, measure current flow
in each individual line. Then, add the individual
readings.

IN-LINE:
Alternatively, to read the current flow in AMPERES,

an in-line ammeter may be used. Most Digital Volt
Ohm Meters (VOM) will have the capability to mea­sure amperes.

This usually requires the positive meter test lead to be
connected to the correct amperes plug, and the meter
to be set to the amperes position. Once the meter is
properly set up to measure amperes the circuit being
measured must be physically broken. The meter will
be in-line or in series with the component being mea­sured.

In Figure 2-4 the control wire to a relay has been
removed. The meter is used to connect and supply
voltage to the relay to energize it and measure the
amperes going to it.

Figure 2-4. – A VOM as an In-line meter

MEASURING RESISTANCE

The volt-ohm-milliammeter may be used to measure
the resistance in a circuit. Resistance values can be

Figure 2-2. – Clamp-On Ammeter

Figure 2-3. – A Line-Splitter

very valuable when testing coils or windings, such as
the Stator and Rotor windings.

When testing Stator windings, keep in mind that the
resistance of these windings is very low. Some meters
are not capable of reading such a low resistance and
will simply read CONTINUITY.

If proper procedures are used, the following condi­tions can be detected using a VOM:

• A “short-to-ground” condition in any Stator or Rotor
winding.

• Shorting together of any two parallel Stator wind
ings.

• Shorting together of any two isolated Stator wind
ings.

• An open condition in any Stator or Rotor winding.

Page 7

-

-

Section 2

-

+

AMPERE - Unit measuring rate of

current flow (number of electrons
past a given point)

OHM - Unit measuring resistance

or opposition to flow

VOLT - Unit measuring force or

difference in potential
causing current flow

Conductor of a
Circuit

VOLTS

(E)

AMPS

(I)

OHMS

(R)

MEASURING ELECTRICITY

Component testing may require a specific resis­tance value or a test for INFINITY or CONTINUITY.
Infinity is an OPEN condition between two electrical
points, which would read as no resistance on a VOM.
Continuity is a CLOSED condition between two elec­trical points, which would be indicated as very low
resistance or “ZERO” on a VOM.

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 (6.25 x 1018).

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 “Hertz”.

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 consid­ered 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.

OHM:
The OHM is the unit of RESISTANCE. In every circuit

there is a 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 temperature. As the conductor's tempera­ture increases, its resistance 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 relationship exists between
VOLTS, OHMS and AMPERES. The value of one can
be calculated 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 resistance
remains the same, and current will decrease when
resistance Increases and voltage remains the same.

Page 8

Figure 2-5. – Electrical Units

Figure 2-6. – Ohm's Law

If AMPERES is unknown while VOLTS and OHMS are
known, use the following formula:

OHMS

If VOLTS is unknown while AMPERES and OHMS are
known, use the following formula:

If OHMS is unknown but VOLTS and AMPERES are
known, use the following:

AMPERES

AMPERES =

VOLTS = AMPERES x OHMS

OHMS

VOLTS

VOLTS

=

Section 3

STATOR

ENGINE

ENGINE

ADAPTOR

REAR BEARING

CARRIER

BRUSH HOLDER

ASSEMBLY

ROTOR

DESCRIPTION & COMPONENTS

INTRODUCTION

The generator revolving field (rotor) is driven by an
air-cooled engine at about 3600 rpm.

The generator may be used to supply electrical power
for the operation of 120 and/or 240 volts, 1-phase, 60
Hz, AC loads.

ENGINE-GENERATOR DRIVE SYSTEM

The generator revolving field is driven by an air­cooled, horizontal crankshaft engine. The generator is
directly coupled to the engine crankshaft (see Figure

1). Both the engine and generator rotor are driven at
approximately 3600 rpm, to provide a 60 Hz AC out­put.

THE AC GENERATOR

Figure 3-1 shows the major components of the AC
generator.

ROTOR ASSEMBLY

The 2-pole rotor must be operated at 3600 rpm to
supply a 60 Hertz AC frequency. The term “2-pole”
means the rotor has a single north magnetic pole and
a single south magnetic pole. As the rotor rotates, its
lines of magnetic flux cut across the stator assem­bly windings and a voltage is induced into the stator
windings. The rotor shaft mounts a positive (+) and
a negative (-) slip ring, with the positive (+) slip ring
nearest the rear bearing carrier (Figure 3-2). The rotor
bearing is pressed onto the end of the rotor shaft. The
tapered rotor shaft is mounted to a tapered crankshaft
and is held in place with a single through bolt.

Figure 3-1. – AC Generator Exploded View

Page 9

Section 3

11

44

22

77A

55

77

6

2

66

66A

55A

44S

11S

4

0

DESCRIPTION & COMPONENTS

Figure 3-2. – The 2-Pole Rotor Assembly

STATOR ASSEMBLY

The stator can houses and retains (a) dual AC power
windings, (b) an excitation winding, and (c) two bat­tery charge windings. A total of thirteen (13) stator
leads are brought out of the stator can as shown in
Figure 3-3.

The stator can is sandwiched between an engine
adapter and a rear bearing carrier. It is retained in that
position by four stator studs.

Wire 4 connects to the positive (+) brush and Wire 0
to the negative (-) brush. Wire 0 connects to frame
ground. Rectified and regulated excitation current, as
well as current from a field boost circuit, are delivered
to the rotor windings via Wire 4, and the positive (+)
brush and slip ring. The excitation and field boost cur­rent passes through the windings and to frame ground
via the negative (-) slip ring and brush, and Wire 0.
This current flow creates a magnetic field around the
rotor having a flux concentration that is proportional to
the amount of current flow.

Figure 3-3. – Stator Assembly Leads

BRUSH HOLDER AND BRUSHES

The brush holder is retained to the rear bearing car­rier by means of two Taptite screws. A positive (+) and
a negative (-) brush are retained in the brush holder,
with the positive (+) brush riding on the slip ring near­est the rotor bearing.

Page 10

Figure 3-4. – Brush Holder and Brushes

OTHER AC GENERATOR COMPONENTS

Some AC generator components are housed in the
generator control panel enclosure. These are (a) an
Excitation Circuit Breaker, (b) a Voltage Regulator,
and (c) a main line circuit breaker.

EXCITATION CIRCUIT BREAKER:
The Excitation Circuit Breaker (CB2) is housed in the

generator control panel enclosure and electrically
connected in series with the excitation (DPE) wind­ing output to the Voltage Regulator. The breaker is
self-resetting, i.e.; its contacts will close again when
excitation current drops to a safe value.

If the circuit breaker has failed open, excitation current
flow to the Voltage Regulator and, subsequently, to
the rotor windings will be lost. Without excitation cur­rent flow, AC voltage induced into the stator AC power
windings will drop to a value that is commensurate
with the rotor residual magnetism (see Figure 3-5).

2

162

Figure 3-5. – Excitation Circuit Breaker

VOLTAGE REGULATOR:
A typical Voltage Regulator is shown in Figure 3-6

(12.5 & 15 kW Units) or Figure 3-7 (17.5 kW Units).
Unregulated AC output from the stator excitation
winding is delivered to the regulator’s DPE termi­nals, via Wire 2, the Excitation Circuit Breaker and
Wire 162, and Wire 6. The Voltage Regulator recti­fies that current and, based on stator AC power
winding sensing, regulates it. The rectified and
regulated excitation current is then delivered to the
rotor windings from the positive (+) and negative (-)
regulator terminals, via Wire 4 and Wire 0. Stator
AC power winding “sensing” is delivered to the reg­ulator “SEN” terminals via Wires 11S and 44S.

The regulator provides “over-voltage” protection, but
does not protect against “under-voltage”. On occur­rence of an “over-voltage” condition, the regulator will
“shut down” and complete loss of excitation current
to the rotor will occur. Without excitation current, the
generator AC output voltage will drop to approximately
one-half (or lower) of the unit’s rated voltage.

Section 3

DESCRIPTION & COMPONENTS

Figure 3-7. – Typical Voltage Regulator Found on 17.5

Units

ADJUSTMENT PROCEDURE (12.5 AND 15 KW UNITS):
The Voltage Regulator is equipped with three light

emitting diodes (LED’s). These LED’s are normally
on during operation with no faults in the system The
RED regulator LED is on when the regulator is on
and functioning. The Yellow sensing LED is powered
by sensing input to the regulator from the stator AC
power windings. The GREEN excitation LED is pow­ered by stator excitation winding output.

Four adjustment potentiometers are provided. They
are VOLTAGE ADJUST, GAIN, STABI LITY, and
UNDERFREQUENCY ADJUST.

1. Connect an AC Voltage/Frequency meter across wires 11 & 44

at the 50A Main circuit breaker. Verify frequency is between

59-61Hz.

2. On the regulator, set the adjustment pots as follows.

a. Voltage Adjust – Pot-turn fully counterclockwise

b. Gain – turn to midpoint (12 O’clock)

c. Stability – turn to midpoint (12 O’clock)

d. Under Frequency – turn to midpoint (12 O’clock)

3. Start the generator. This adjustment will be done under a no-

load condition.

Figure 3-6. – Typical Voltage Regulator Found on 12.5

kW and 15 kW Units

4. Turn the regulator’s Voltage Adjust pot clockwise to obtain a line

to line voltage of 238-242 VAC.

5. If the red regulator LED is flashing, slowly turn the stability pot

either direction until flashing stops.

ADJUSTMENT PROCEDURE (17.5 KW UNITS):
A single red lamp (LED) glows during normal opera-

tion. The lamp will become dim if excitation winding
AC output diminishes. It will go out on occurrence of
an open condition in the sensing AC output circuit.

An adjustment potentiometer permits the stator AC
power winding voltage to be adjusted. Perform this
adjustment with the generator running at no-load, and

Page 11

Section 3
DESCRIPTION & COMPONENTS

with a 62 Hz AC frequency (62 Hz equals 3720 rpm).
At the stated no-load frequency, adjust to obtain a
line-to-line AC voltage of about 252 volts.

CIRCUIT BREAKERS:
Each individual outlet on the generator is protected by

a circuit breaker to prevent overload.

ROTOR RESIDUAL MAGNETISM

The generator revolving field (rotor) may be consid­ered to be a permanent magnet. Some “residual”
magnetism is always present in the rotor. This residu­al magnetism is sufficient to induce a voltage into the
stator AC power windings that is approximately 2-12
volts AC.

FIELD BOOST CIRCUIT

When the engine is cranked during star t-up, the
START/STOP RELAY (SSR) will be energized. The
normally open contacts of the SSR will close and Wire
15 will supply 12 VDC to Wire 14. Connected to Wire
14 is a resistor (R1) and a diode (D1). The resistor
will limit current flow, and the diode will block Voltage
Regulator DC output. Once through the resistor and
diode it becomes Wire 4, and Wire 4 then connects
to the positive brush. The effect is to “flash the field”
every time the engine is cranked. Field boost current
helps ensure that sufficient “pickup” voltage is avail­able on every startup to turn the Voltage Regulator on
and build AC output voltage.

Notice that field boost current is always available dur­ing cranking and running, this is because the SSR is
energized the whole time. The diode (D1) prevents or
blocks the Voltage Regulators higher DC output from
reaching the Wire 14 run circuit.

Field boost voltage is reduced from that of battery
voltage by the resistor (R1), and when read with a DC
voltmeter will be approximately 9 or 10 volts DC.

OPERATION

STARTUP:
When the engine is started, residual plus field boost

magnetism from the rotor induces a voltage into (a)
the stator AC power windings, (b) the stator excitation
or DPE windings, (c) the stator battery charge wind­ings. In an “on-speed” (engine cranking) condition,
residual plus field boost magnetism are capable of
creating approximately one-half the unit’s rated volt­age.

ON-SPEED OPERATION:
As the engine accelerates, the voltage that is induced

into the stator windings increases rapidly, due to the
increasing speed at which the rotor operates.

FIELD EXCITATION:
An AC voltage is induced into the stator excitation

(DPE) windings. The DPE winding circuit is completed
to the Voltage Regulator, via Wire 2, Excitation Circuit
Breaker, Wire 162, and Wire 6. Unregulated alternat­ing current can flow from the winding to the regulator.

The Voltage Regulator “senses” AC power winding
output voltage and frequency via stator Wires 11S and
44S.

The regulator changes the AC from the excitation
winding to DC. In addition, based on the Wires 11S
and 44S sensing signals, it regulates the flow of direct
current to the rotor.

The rectified and regulated current flow from the regu­lator is delivered to the rotor windings, via Wire 4, and
the positive brush and slip ring. This excitation current
flows through the rotor windings and is directed to
ground through the negative (-) slip ring and brush,
and Wire 0.

The greater the current flow through the rotor wind­ings, the more concentrated the lines of flux around
the rotor become.

The more concentrated the lines of flux around the
rotor that cut across the stationary stator windings,
the greater the voltage that is induced into the stator
windings.

Initially, the AC power winding voltage sensed by the
regulator is low. The regulator reacts by increasing
the flow of excitation current to the rotor until volt­age increases to a desired level. The regulator then
maintains the desired voltage. For example, if voltage
exceeds the desired level, the regulator will decrease
the flow of excitation current. Conversely, if voltage
drops below the desired level, the regulator responds
by increasing the flow of excitation current.

AC POWER WINDING OUTPUT:
A regulated voltage is induced into the stator AC

power windings. When electrical loads are connected
across the AC power windings to complete the cir­cuit, current can flow in the circuit. The regulated AC
power winding output voltage will be in direct propor­tion to the AC frequency. For example, on units rated
120/240 volts at 60 Hz, the regulator will try to main­tain 240 volts (line-to-line) at 60 Hz. This type of regu­lation system provides greatly improved motor starting
capability over other types of systems.

BATTERY CHARGE WINDING OUTPUT:
A voltage is induced into the battery charge winding.

Output from these windings is delivered to a Battery
Charge Rectifier (BCR2), via Wires 55A, 66A and
77A. The resulting direct current from the BCR is
delivered to the unit battery, via Wire 15, a 10 amp
fuse, and Wire 13. This output is used to maintain bat­tery state of charge during operation.

10 AMP BATTERY CHARGE WINDING OUTPUT:
A voltage is induced into the battery charge winding.

Output from these windings is delivered to a Battery
Charge Rectifier (BCR1), via Wires 55, 66 and 77.

Page 12

Section 3

DESCRIPTION & COMPONENTS

The resulting direct current from the BCR is delivered
to the 12 VDC receptacle, via Wire 13A, CB1, and
Wire 15A. This receptacle allows the capability to
recharge a 12 volt DC storage battery with provided
battery charge cables.

INSULATION RESISTANCE

The insulation resistance of stator and rotor wind­ings is a measurement of the integrity of the insulat­ing materials that separate the electrical windings
from the generator steel core. This resistance can
degrade over time or due to such contaminants as
dust, dir t, oil, grease and especially moisture. In
most cases, failures of stator and rotor windings is
due to a breakdown in the insulation. In many cases,
a low insulation resistance is caused by moisture
that collects while the generator is shut down. When
problems are caused by moisture buildup on the
windings, they can usually be corrected by drying the
windings. Cleaning and drying the windings can usu­ally eliminate dirt and moisture built up in the genera­tor windings.

THE MEGOHMMETER

GENERAL:
A megohmmeter, often called a “megger”, consists of

a meter calibrated in megohms and a power supply.
Use a power supply of 500 volts when testing stators
or rotors. DO NOT APPLY VOLTAGE LONGER THAN
ONE (1) SECOND.

TESTING STATOR INSULATION:
All parts that might be damaged by the high meg-

ger voltages must be disconnected before testing.
Isolate all stator leads (Figure 3-9) and connect all of
the stator leads together. FOLLOW THE MEGGER
MANUFACTURER’S INSTRUCTIONS CAREFULLY.

Use a megger power setting of 500 volts. Connect one
megger test lead to the junction of all stator leads, the
other test lead to frame ground on the stator can.
Read the number of megohms on the meter.

The MINIMUM acceptable megger reading for stators
may be calculated using the following formula:

windings as outlined “Stator Insulation Tests”.
Also test between parallel windings. See “Test

Between Windings” on next page.

TESTING ROTOR INSULATION:
Apply a voltage of 500 volts across the rotor positive

(+) slip ring (nearest the rotor bearing), and a clean
frame ground (i.e. the rotor shaft). DO NOT EXCEED
500 VOLTS AND D O NOT APPLY VOLTAGE
LON GER THA N 1 SEC OND. FOL LOW T HE
MEGGER MANUFACTURER’S INSTRUCTIONS
CAREFULLY.

ROTOR MINIMUM INSULATION RESISTANCE:

1.5 megohms

CAUTION: Before attempting to measure

*

Insulation resistance, first disconnect and
Isolate all leads of the winding to be tested.
Electronic components, diodes, surge protec

­tors, relays, Voltage Regulators, etc., can be
destroyed if subjected to high megger volt­ages.

HI-POT TESTER:
A “Hi-Pot” tester is shown in Figure 3-8. The model

shown is only one of many that are commercially
available. The tester shown is equipped with a voltage
selector switch that permits the power supply voltage
to be selected. It also mounts a breakdown lamp that
will illuminate to indicate an insulation breakdown dur­ing the test.

MINIMUM INSULATION
RESISTANCE =
(in “Megohms”)

GENERATOR RATED VOLTS

__________________________

1000

+1

EXAMPLE: Generator is rated at 120 volts AC.
Divide “120” by “1000” to obtain “0.12”. Then add
“1” to obtain “1.12” megohms. Minimum insulation
resistance for a 120 VAC stator is 1.12 megohms.

If the stator insulation resistance is less than the cal­culated minimum resistance, clean and dry the stator.
Then, repeat the test. If resistance is still low, replace
the stator.

Use the Megger to test for shorts between isolated

Figure 3-8. – One Type of Hi-Pot Tester

STATOR INSULATION RESISTANCE TEST

GENERAL:
Units with air-cooled engines are equipped with (a)

center tapped AC power windings, (b) an excitation

Page 13

Section 3

11

44

22

77A

55

77

6

2

66

66A

55A

44S

11S

PIN

LOCATION

6

PIN

LOCATION

7

PIN

LOCATION

1

PIN

LOCATION

12

2

77A

66A

55A

44S

11S

0

4

77

66

55

6

DESCRIPTION & COMPONENTS

or DPE winding, (c) a center tapped battery charge
winding and (d) a 10 Amp center tapped battery
charge winding. Insulation tests of the stator con­sist of (a) testing all windings to ground, (b) testing
between isolated windings, and (c) testing between
parallel windings. Figure 3-9 is a pictorial representa­tion of the various stator leads on units with air-cooled
engine.

TESTING ALL STATOR WINDINGS TO GROUND:

1. Disconnect stator output leads Wire 11 and Wire 44 from the

generator 50A circuit breaker.

2. Remove stator output lead Wire 22 from the neutral terminal

on the back of the 50A outlet.

3. Disconnect the C1 connector from the bottom of the control

panel. See Figure 3-10. The C1 connector is on the right when

facing the control panel.

cleaning and drying, the stator fails the second test,
the stator assembly should be replaced.

6. Now proceed to th e C1 connector ( Fem ale side – Just

removed). Each winding will be individually tested for a short

to ground. Insert a large paper clip (or similar item) into the C1

connector at the following pin locations:

Pin

Location

1 11S Sense Lead Power

2 44S Sense Lead Power

3 55A Battery Charge

4 66A Battery Charge

5 77A Battery Charge

6 2 Excitation

7 6 Excitation

8 55 10 Amp Battery Charge

9 66 10 Amp Battery Charge

10 77 10 Amp Battery Charge

11 4

12 0

Wire

Number

Winding

(Positive lead to Brush)

(Negative lead to Brush)

Figure 3-9. – Stator Winding Leads

4. Connect the terminal ends of Wires 11, 22, and 44 together.

Make sure the wire ends are not touching any part of the gen-

erator frame or any terminal.

5. Connect the red test probe of the Hi-Pot tester to the joined

terminal ends of stator leads 11, 22, and 44. Connect the black

tester lead to a clean frame ground on the stator can. With tes

ter leads connected in this manner, proceed as follows:

a. Turn the Hi-Pot tester switch OFF.
b. Plug the tester cord into a 120 volt AC wall sock

et and set its voltage selector switch to “1500
volts”.

c. Turn the tester switch ON and observe the

breakdown lamp on tester. DO NOT APPLY
VOLTAGE LONGER THAN 1 SECOND. After
one (1) second, turn the tester switch OFF.

If the breakdown lamp comes on during the one-sec­ond test, the stator should be cleaned and dried. After
cleaning and drying, repeat the insulation test. If, after

Page 14

Next refer to Steps 5a through 5c of the Hi-Pot proce­dure.

Example: Insert paper clip into Pin 1, Hi-Pot from
Pin 1 (Wire 11S) to ground. Proceed to Pin 2, Pin
3, etc. through Pin 10.

-

Figure 3-10. – C1 Connector Pin Location Numbers

(Female Side, Located to the Right When Facing the

-

Control Panel)

TEST BETWEEN WINDINGS:

1. Insert a paper clip into Pin Location 3 (Wire 55A). Connect

the red tester probe to the paper clip. Connect the black tes-

ter probe to Stator Lead 11. Refer to Steps 5a through 5c of

“TESTING ALL STATOR WINDINGS TO GROUND”.

2. Repeat Step 1 at Pin Location 6 (Wire 2) and Stator Lead 11.

Section 3

POSITIVE (+)
TEST LEAD

DESCRIPTION & COMPONENTS

3. Repeat Step 1 at Pin Location 8 (Wire 55) and Stator Lead 11.

For the following steps (4 through 6) an additional
paper clip (or similar item) will be needed:

4. Insert a paper clip into Pin Location 3 (Wire 55A). Connect the

red tester probe to the paper clip. Insert additional paper clip

into Pin Location 6 (Wire 2). Connect the black tester probe to

this paper clip. Refer to Steps 5a through 5c of “TESTING ALL

STATOR WINDINGS TO GROUND” on the previous page.

5. Insert a paper clip into Pin Location 3 (Wire 55A). Connect the

red tester probe to the paper clip. Insert additional paper clip

into Pin Location 8 (Wire 55). Connect the black tester probe to

this paper clip. Refer to Steps 5a through 5c of “TESTING ALL

STATOR WINDINGS TO GROUND” on the previous page.

6. Insert a paper clip into Pin Location 6 (Wire 2). Connect the red

tester probe to the paper clip. Insert the additional paper clip

into Pin Location 8 (Wire 55). Connect the black tester probe to

this paper clip. Refer to Steps 5a through 5c of “TESTING ALL

STATOR WINDINGS TO GROUND” on the previous

page.

ROTOR INSULATION RESISTANCE TEST

Before attempting to test rotor insulation, the brush
holder must be completely removed. The rotor must
be completely isolated from other components before
starting the test. Attach all leads of all stator windings
to ground.

1. Connect the red tester lead to the positive (+) slip ring (nearest

the rotor bearing).

2. Connect the black tester probe to a clean frame ground, such

as a clean metal part of the rotor shaft.

3. Turn the tester switch OFF.

4. Plug the tester into a 120 volts AC wall socket and set the volt

age switch to “1500 volts”.

5. Turn the tester switch “On” and make sure the pilot light has

turned on.

6. Observe the breakdown lamp, then turn the tester switch OFF.

DO NOT APPLY VOLTAGE LONGER THAN ONE (1) SECOND.

If the breakdown lamp came on during the one (1)
second test, cleaning and drying of the rotor may be
necessary. After cleaning and drying, repeat the insu­lation breakdown test. If breakdown lamp comes on
during the second test, replace the rotor assembly.

CLEANING THE GENERATOR

Caked or greasy dirt may be loosened with a soft
brush or a damp cloth. A vacuum system may be
used to clean up loosened dirt. Dust and dirt may
also be removed using dry, low-pressure air (25 psi
maximum).

CAUTION: Do not use sprayed water to clean

*

the generator. Some of the water will be
retained on generator windings and terminals,
and may cause very serious problems.

DRYING THE GENERATOR

To dry a generator, proceed as follows:

1. Open the generator main circuit breaker. NO ELECTRICAL

LOADS MUST BE APPLIED TO THE GENERATOR WHILE

DRYING.

-

Figure 3-10. – Testing Rotor Insulation

2. Provide an external source to blow warm, dry air through the

generator interior (around the rotor and stator windings. DO

NOT EXCEED 185° F. (85° C.).

3. Start the generator and let it run for 2 or 3 hours.

4. Shut the generator down and repeat the stator and rotor insula

tion resistance tests.

Page 15

-

Section 4

DIP SWITCH

1) ON

2) OFF

J2 CONNECTOR

J1 CONNECTOR

POTENTIOMETERS

RESPONSE

RECOVERY

DAMPEN

SENSING

LED

21

ON

ENGINE DC CONTROL SYSTEM

PRINTED CIRCUIT BOARD

GENERAL:
The printed board is responsible for cranking, startup,

running and shutdown operations. The board intercon­nects with other components of the DC control system
to turn them on and off at the proper times. It is pow­ered by fused 12 VDC power from the unit battery.

CIRCUIT BOARD CONNECTIONS:
The circuit board mounts a 12-pin receptacle (J2) and

a 5-pin receptacle (J1). Figure 4-2 shows the 12-pin
receptacle (J2), the associated wires and the function
of each pin and wire.

DIP SWITCH POSITIONS:

Note: These switches must remain in the positions
set at the factory.

1. Stepper Motor Rotation

a. Switch set to ON for clockwise rotation (Factory

Position).

b. Switch set to OFF for counterclockwise rotation.

2. Frequency Setting

a. Switch set to OFF fo r 60 Her tz (Factor y

Position).

b. Switch set to ON for 50 Hertz.

TERMINAL WIRE FUNCTION

1 15B 12 VDC input when the Start Stop Relay

2 83 Ground input when the idle control switch

3 TR1 AC voltage input from the idle control

4 0 Common ground for the PCB

5 167 12 VDC input when SW1 is placed in the

6 TR2 AC voltage input from the idle control

7 86 Fault shutdown circuit. When grounded

8 229 Switched to ground for Start Stop Relay

9 NOT USED

10 44S AC input for frequency control.

11 NOT USED

12 11S AC input for frequency control. 11S/44S

Note: J1 Connector is utilized for governor control.

(SSR) is energized.

(SW2) is placed in the closed position

transformers.

Start position. Ground input when SW1 is
placed in the Stop position.

transformers.

by closure of the Low Oil pressure switch
(LOP) engine will shut down.

(SSR) operation.

11S/44S 240VAC

240VAC

Figure 4-2. – Receptacle J2

BATTERY

RECOMMENDED BATTERY:
When anticipated ambient temperatures will be con-

sistently above 32° F. (0° C.), use a 12 volts Type U1
storage battery capable of delivering at least 300 cold
cranking amperes.

Page 16

Figure 4-1. – Printed Circuit Board

ENGINE DC CONTROL SYSTEM

VOLTAGE

REGULATOR

TERMINAL BOARD

(TB1)

TERMINAL BOARD

(TB2)

START STOP RELAY

(SSR)

STARTER CONTACTOR RELAY

(SCR)

IDLE CONTROL

TRANSFORMERS

(ICT)

PRINTED CIRCUIT

BOARD

10 AMP FUSE (F1)

LOCATED IN REAR OF CONTROL PANEL

DIODE (D1)

RESISTOR (R1)

CONNECTOR

(C2)

CONNECTOR

(C1)

50 AMP CIRCUIT BREAKER

EXCITATION CIRCUIT

BREAKER (CB2)

10 AMP AUTO RESET

BREAKER (CB1)

BATTERY CHARGE RECTIFIERS

(BCR1 & BCR2)

CONTROL PANEL COMPONENT IDENTIFICATION

Section 4

Page 17

Section 4

PIN

LOCATION

6

PIN

LOCATION

7

C1 FEMALE SIDE

C2 FEMALE SIDE

C1 MALE SIDE

C2 MALE SIDE

PIN

LOCATION

1

PIN

LOCATION

12

2

77A

66A

55A

44S

11S

0

4

77

66

55

6

PIN

LOCATION

7

PIN

LOCATION

6

0

4

77

66

55

6

2

77A

66A

55A

44S

11S

PIN

LOCATION

6

PIN

LOCATION

7

PIN

LOCATION

1

PIN

LOCATION

12

13

86

167

0

15

18

0

13

15

16

17

14

PIN

LOCATION

7

PIN

LOCATION

6

0

13

15

16

17

14

13

86

167

0

15

18

TERMINAL BLOCK

(TB1)

TERMINAL BLOCK

(TB2)

86 15B

167

BLK

0 229

83

BLK

TR2

TR1

44S

11S

ENGINE DC CONTROL SYSTEM

Page 18

NOTES

Page 19

Section 4

VOLTAGE

ELECTRONIC

REGULATOR

11S

162

0

6

44S

4

6

5

4

3

2

1

BCR2

77A

15

66A

564

1012

SSR

9

18

PRINTED CIRCUIT

BOARD

CONTROL

12 1011 9 278 6 45 3J21

J1

15B83TR10167

TR286229

44S

11S

ACTUATOR

GOVERNOR

11B

0

22

50A

C.B.

30A

C.B.

FIELD

BATTERY CHARGE WINDING

55A

10A BATTERY CHARGE WINDING

77

55

11S

112244

44S

66

77A 66A

62 4 0

C1-12C1-11C1-7C1-6C1-1

C1-2

C1-4

C1-9

C1-8

C1-10

C1-5

C1-3

77

66

BCR1

13A

CB2

83

167

229

15B

0

86

SW2

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

C2-12

16

SC

CB1

15A 0

C2-6

C2-11

C2-9

13

13

F1

SCR

22914

15B

18

01515 15

0

0

0

167

15

15

86

0

14

17

18

13

13

16

14

14

14

14

86

13

15

15

1515

15

15

15

15

14

18 18

167167

8686

4

4

162

11S

44S

22

11

0

44

11

0

22

4444

77A

77

66A

66

77

0

2

2

2

6

6

6

11S 4 044S

RED

BLK

BLK

83 0

0

00

0

229

15B

15

15

15

0

17

17

4

120/240V

POWER WINDING

DPE WINDING

I.C.T.

I.C.T.

I.C.

R1D1

TB1

TB2

12Vdc

BA

13

14

13

ENGINE DC CONTROL SYSTEM

Battery voltage is supplied to components of the control system from the unit BATTERY via the RED battery cable
connected to the contacts of the starter contactor (SC), wire 13, a 10 Amp fuse (F1), and Wire 15.

Wire 13 is unfused battery supply voltage and is connected to the contacts of the Starter Contactor Relay (SCR).
Wire 15 12 VDC fused battery supply voltage is supplied to the SCR coil, it goes through the coil and comes out

as wire 17 12 VDC, wire 17 is connected to the Start-Run-Stop switch (SW1) and is held open to ground. No cur­rent flows through the circuit and the SCR is de-energized.

Wire 15 12 VDC fused battery supply voltage is supplied to SW1 and is held open to Wire 167.
Wire 15 12 VDC fused battery supply voltage is supplied to the Start-Stop Relay (SSR) it goes through the coil

and comes out as wire 229 12 VDC, wire 229 is connected to the printed circuit board and is held open to ground.
No current flows through the circuit and the SSR is de-energized.

Page 20

CIRCUIT CONDITION - REST:

Section 4

RESET

RESET

TEST

TEST

18

IM2

SP2

IM1

SP1

0 0 44C2211C22

C.B.

0000

222222

44D11D44B

11B

11B

0

11A44A

22

20A

C.B.
20A30A

C.B.

30A

C.B.

30A

C.B.

50A

C.B.

30A

C.B.

0

167

SW1

FSS

LOP

0

15

17

0

17

15

0

0

86

14

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

15

C2-12

0

0

16

SC

BATTERY

BLACK

RED

SC

SM

12V

C2-6

C2-11

C2-9

13

13

SCR

0

0

167

15

15

86

0

14

17

18

13

13

16

86

15

15

22

11

0

44

11

0

22

44

11

0

22

44

17

17

SCR - STARTER CONTACTOR RELAY

SW1 - START-RUN-STOP SWITCH

SSR - START / STOP RELAY

SP2 - SPARK PLUG, CYL. 2

SP1 - SPARK PLUG, CYL. 1

SM - STARTER MOTOR

SC - STARTER CONTACTOR

R1 - 25 OHM, 25W RESISTOR

IM2 - IGNITION MODULE, CYL. 2

FSS - FUEL SHUT OFF SOLENOID

CB1 - 10AMP AUTO RESET BREAKER

LOP - LOW OIL PRESSURE

IM1 - IGNITION MODULE, CYL. 1

GND - GROUND BAR

F1 - 10A FUSE

D2, D3 - ENGINE SHUTDOWN DIODE

BA - BRUSH ASSEMBLY

LEGEND

120/240V

50A

TWISTLOK TWISTLOK

120V/30A

TWISTLOK

120V/30A

DUPLEX

120V 120V

GFCI

30A

120/240V

D2

D3

CB2 - 5AMP AUTO RESET BREAKER
D1 - 600V 12A DIODE

BCR2 - BATTERY CHARGE RECTIFIER

BCR1 - BATTERY CHARGE RECTIFIER, 10A

I.C.T. - IDLE CONTROL TRANSFORMER

SW2 - IDLE CONTROL SWITCH
TB1, TB2 - TERMINAL BLOCK

13

= 12 VDC SUPPLY

= 12 VDC CONTROL

= AC POWER

= GROUND

ENGINE DC CONTROL SYSTEM

Wire 15 12 VDC fused battery supply voltage is supplied to the normally open contacts of the SSR. One set of
normally open contacts are connected to Wire 15B, the other set of normally open contacts are connected to Wire

14. The SSR is de-energized and no voltage is available through the contacts.
Wire 15 12 VDC fused battery supply voltage is supplied to the Battery Charge Rectifier number 2 (BCR2). This is

a return current path for battery charging. No current flows at this time.
Wire 18 connects to the ignition magnetos and to the normally closed contacts of the SSR. The normally closed

contacts are also connected to Wire 0, Wire 0 is frame ground.
The SSR is de-energized and the magnetos are grounded out at this time, no spark is available.

Page 21

Section 4

VOLTAGE

ELECTRONIC

REGULATOR

11S

162

0

6

44S

4

6

5

4

3

2

1

BCR2

77A

15

66A

564

1012

SSR

9

18

PRINTED CIRCUIT

BOARD

CONTROL

12 1011 9 278 6 45 3J21

J1

15B83TR10167

TR286229

44S

11S

ACTUATOR

GOVERNOR

11B

0

22

50A

C.B.

30A

C.B.

FIELD

BATTERY CHARGE WINDING

55A

10A BATTERY CHARGE WINDING

77

55

11S

112244

44S

66

77A 66A

62 4 0

C1-12C1-11C1-7C1-6C1-1

C1-2

C1-4

C1-9

C1-8

C1-10

C1-5

C1-3

77

66

BCR1

13A

CB2

83

167

229

15B

0

86

SW2

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

C2-12

16

SC

CB1

15A 0

C2-6

C2-11

C2-9

13

13

F1

SCR

22914

15B

18

01515 15

0

0

0

167

15

15

86

0

14

17

18

13

13

16

14

14

14

14

86

13

15

15

1515

15

15

15

15

14

18 18

167167

8686

4

4

162

11S

44S

22

11

0

44

11

0

22

4444

77A

77

66A

66

77

0

2

2

2

6

6

6

11S 4 044S

RED

BLK

BLK

83 0

0

00

0

229

15B

15

15

15

0

17

17

4

120/240V

POWER WINDING

DPE WINDING

I.C.T.

I.C.T.

I.C.

R1D1

TB1

TB2

12Vdc

BA

13

14

13

ENGINE DC CONTROL SYSTEM

With the Start-Run-Stop Switch (SW1) held in the start position, Wire 17 from the Starter Contactor Relay (SCR)
is now connected to Wire 0 which is frame ground. This allows current to flow and the SCR is energized. The SCR
contacts close connecting Wire 13 battery power to Wire 16. Wire 16 now supplies battery power to the starter
contactor (SC) on the Starter Motor (SM), the SC is energized and its contacts close, battery power is available to
the Starter Motor (SM) and the engine is cranking.

Page 22

CIRCUIT CONDITION - START:

Section 4

RESET

RESET

TEST

TEST

18

IM2

SP2

IM1

SP1

0 0 44C2211C22

C.B.

0000

222222

44D11D44B

11B

11B

0

11A44A

22

20A

C.B.
20A30A

C.B.

30A

C.B.

30A

C.B.

50A

C.B.

30A

C.B.

0

167

SW1

FSS

LOP

0

15

17

0

17

15

0

0

86

14

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

15

C2-12

0

0

16

SC

BATTERY

BLACK

RED

SC

SM

12V

C2-6

C2-11

C2-9

13

13

SCR

0

0

167

15

15

86

0

14

17

18

13

13

16

86

15

15

22

11

0

44

11

0

22

44

11

0

22

44

17

17

SCR - STARTER CONTACTOR RELAY

SW1 - START-RUN-STOP SWITCH

SSR - START / STOP RELAY

SP2 - SPARK PLUG, CYL. 2

SP1 - SPARK PLUG, CYL. 1

SM - STARTER MOTOR

SC - STARTER CONTACTOR

R1 - 25 OHM, 25W RESISTOR

IM2 - IGNITION MODULE, CYL. 2

FSS - FUEL SHUT OFF SOLENOID

CB1 - 10AMP AUTO RESET BREAKER

LOP - LOW OIL PRESSURE

IM1 - IGNITION MODULE, CYL. 1

GND - GROUND BAR

F1 - 10A FUSE

D2, D3 - ENGINE SHUTDOWN DIODE

BA - BRUSH ASSEMBLY

LEGEND

120/240V

50A

TWISTLOK TWISTLOK

120V/30A

TWISTLOK

120V/30A

DUPLEX

120V 120V

GFCI

30A

120/240V

D2

D3

CB2 - 5AMP AUTO RESET BREAKER
D1 - 600V 12A DIODE

BCR2 - BATTERY CHARGE RECTIFIER

BCR1 - BATTERY CHARGE RECTIFIER, 10A

I.C.T. - IDLE CONTROL TRANSFORMER

SW2 - IDLE CONTROL SWITCH
TB1, TB2 - TERMINAL BLOCK

13

= 12 VDC SUPPLY

= 12 VDC CONTROL

= AC POWER

= GROUND

ENGINE DC CONTROL SYSTEM

With the Start-Run-Stop Switch (SW1) held in the start position, Wire 15 is now connected to Wire 167. Wire
15 supplies fused battery power via Wire 167 to the Printed Circuit Board. This 12 VDC input signals the Printed
Circuit Board to internally ground Wire 229 which is connected to the coil of the Start-Stop-Relay (SSR). This
action allows current to flow and the SSR is energized. The normally open contacts close supplying battery power
from Wire 15 to Wire 14. Wire 14 supplies power to the Fuel Shutoff Solenoid (FSS), it is energized and fuel is
available to the engine. Wire 14 supplies power through Resistor (R1) and Diode (D1) to Wire 4, Wire 4 connects
to the field or the Rotor assembly and is used as Field Boost. The second set of normally open contacts also
close connecting Wire 15 12 VDC battery supply to Wire 15B. Wire 15B now supplies 12 VDC to the printed circuit
board for use with the governor control system. The normally closed contacts now open, Wire 18 is no longer con­nected to Wire 0 and the magnetos are no longer grounded out and can produce spark.

Page 23

Section 4

VOLTAGE

ELECTRONIC

REGULATOR

11S

162

0

6

44S

4

6

5

4

3

2

1

BCR2

77A

15

66A

564

1012

SSR

9

18

PRINTED CIRCUIT

BOARD

CONTROL

12 1011 9 278 6 45 3J21

J1

15B83TR10167

TR286229

44S

11S

ACTUATOR

GOVERNOR

11B

0

22

50A

C.B.

30A

C.B.

FIELD

BATTERY CHARGE WINDING

55A

10A BATTERY CHARGE WINDING

77

55

11S

112244

44S

66

77A 66A

62 4 0

C1-12C1-11C1-7C1-6C1-1

C1-2

C1-4

C1-9

C1-8

C1-10

C1-5

C1-3

77

66

BCR1

13A

CB2

83

167

229

15B

0

86

SW2

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

C2-12

16

SC

CB1

15A 0

C2-6

C2-11

C2-9

13

13

F1

SCR

22914

15B

18

01515 15

0

0

0

167

15

15

86

0

14

17

18

13

13

16

14

14

14

14

86

13

15

15

1515

15

15

15

15

14

18 18

167167

8686

4

4

162

11S

44S

22

11

0

44

11

0

22

4444

77A

77

66A

66

77

0

2

2

2

6

6

6

11S 4 044S

RED

BLK

BLK

83 0

0

00

0

229

15B

15

15

15

0

17

17

4

120/240V

POWER WINDING

DPE WINDING

I.C.T.

I.C.T.

I.C.

R1D1

TB1

TB2

12Vdc

BA

13

14

13

ENGINE DC CONTROL SYSTEM

Once the engine has started the Start-Run-Stop Switch (SW1) is released and will be in the run position, at this
point SW1 is not activated. This action will de-energize the Starter Contactor Relay (SCR) causing the Starter
Motor to disengage.

Printed circuit board action keeps Wire 229 held to ground this action holds the Start-Stop Relay (SSR) energized.
With the SSR energized Wire 14 maintains 12 VDC to the Fuel Shutoff Solenoid. Once the Voltage Regulator
starts functioning the field boost circuit is no longer a factor in operation. With the SSR energized Wire 15B main­tains 12 VDC to the printed circuit board. With the SSR energized Wire 18 is not grounded and the magnetos con­tinue to produce spark.

The two independent battery charge windings are now producing AC voltage and supplying this to BCR1 and
BCR2. The AC voltage is rectified through BCR1 and used to supply DC voltage to the 12 VDC accessory outlet.
The AC voltage is rectified through BCR2 and used to supply DC voltage to the battery for battery charging.

Page 24

CIRCUIT CONDITION - RUN:

Section 4

RESET

RESET

TEST

TEST

18

IM2

SP2

IM1

SP1

0 0 44C2211C22

C.B.

0000

222222

44D11D44B

11B

11B

0

11A44A

22

20A

C.B.
20A30A

C.B.

30A

C.B.

30A

C.B.

50A

C.B.

30A

C.B.

0

167

SW1

FSS

LOP

0

15

17

0

17

15

0

0

86

14

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

15

C2-12

0

0

16

SC

BATTERY

BLACK

RED

SC

SM

12V

C2-6

C2-11

C2-9

13

13

SCR

0

0

167

15

15

86

0

14

17

18

13

13

16

86

15

15

22

11

0

44

11

0

22

44

11

0

22

44

17

17

SCR - STARTER CONTACTOR RELAY

SW1 - START-RUN-STOP SWITCH

SSR - START / STOP RELAY

SP2 - SPARK PLUG, CYL. 2

SP1 - SPARK PLUG, CYL. 1

SM - STARTER MOTOR

SC - STARTER CONTACTOR

R1 - 25 OHM, 25W RESISTOR

IM2 - IGNITION MODULE, CYL. 2

FSS - FUEL SHUT OFF SOLENOID

CB1 - 10AMP AUTO RESET BREAKER

LOP - LOW OIL PRESSURE

IM1 - IGNITION MODULE, CYL. 1

GND - GROUND BAR

F1 - 10A FUSE

D2, D3 - ENGINE SHUTDOWN DIODE

BA - BRUSH ASSEMBLY

LEGEND

120/240V

50A

TWISTLOK TWISTLOK

120V/30A

TWISTLOK

120V/30A

DUPLEX

120V 120V

GFCI

30A

120/240V

D2

D3

CB2 - 5AMP AUTO RESET BREAKER
D1 - 600V 12A DIODE

BCR2 - BATTERY CHARGE RECTIFIER

BCR1 - BATTERY CHARGE RECTIFIER, 10A

I.C.T. - IDLE CONTROL TRANSFORMER

SW2 - IDLE CONTROL SWITCH
TB1, TB2 - TERMINAL BLOCK

13

= 12 VDC SUPPLY

= 12 VDC CONTROL

= AC POWER

= GROUND

= IDLE CONTROL TRANSFORMER OUTPUT

ENGINE DC CONTROL SYSTEM

The printed circuit board is supplied with AC voltage from Wires 11S and 44S, this voltage /frequency signal is
used by the printed circuit board for governor control operation.

When the Idle Control Switch (SW2) is activated to the “ON” position Wire 83 from the printed circuit board will be
connected to Wire 0 frame ground. There are two Idle Control Transformers (ICT) that sense current flow off the
main power windings. The voltage signal from the ICT’s connect to the Printed Circuit Board via Wires TR1/TR2
and are used for sensing load on the generator. With no-load on the generator there is no current supplied from
the ICT’s and the engine will run at a lower RPM. When a load is applied to the generator the ICT’s supply a
voltage signal to the Printed Circuit Board and the engine RPM will be increased to running RPM approximately
3600RPM.

Page 25

Section 4

VOLTAGE

ELECTRONIC

REGULATOR

11S

162

0

6

44S

4

6

5

4

3

2

1

BCR2

77A

15

66A

564

1012

SSR

9

18

PRINTED CIRCUIT

BOARD

CONTROL

12 1011 9 278 6 45 3J21

J1

15B83TR10167

TR286229

44S

11S

ACTUATOR

GOVERNOR

11B

0

22

50A

C.B.

30A

C.B.

FIELD

BATTERY CHARGE WINDING

55A

10A BATTERY CHARGE WINDING

77

55

11S

112244

44S

66

77A 66A

62 4 0

C1-12C1-11C1-7C1-6C1-1

C1-2

C1-4

C1-9

C1-8

C1-10

C1-5

C1-3

77

66

BCR1

13A

CB2

83

167

229

15B

0

86

SW2

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

C2-12

16

SC

CB1

15A 0

C2-6

C2-11

C2-9

13

13

F1

SCR

22914

15B

18

01515 15

0

0

0

167

15

15

86

0

14

17

18

13

13

16

14

14

14

14

86

13

15

15

1515

15

15

15

15

14

18 18

167167

8686

4

4

162

11S

44S

22

11

0

44

11

0

22

4444

77A

77

66A

66

77

0

2

2

2

6

6

6

11S 4 044S

RED

BLK

BLK

83 0

0

00

0

229

15B

15

15

15

0

17

17

4

120/240V

POWER WINDING

DPE WINDING

I.C.T.

I.C.T.

I.C.

R1D1

TB1

TB2

12Vdc

BA

13

14

13

ENGINE DC CONTROL SYSTEM

With the Start-Run-Stop Switch (SW1) placed in the Stop position Wire 167 is connected to Wire 0 which is frame
ground. The ground signal is supplied via Wire 167 to the Printed Circuit Board. The Printed Circuit Board will
open Wire 229 from ground; this action will de-energize the Start-Stop Relay (SSR). With the SSR de-energized
Wire 14 will no longer have 12 VDC supplied to it through the relay, this de-energizes the Fuel Shutoff Solenoid
(FSS) stopping fuel to the engine. With the SSR de-energized Wire 18 will now be connected to Wire 0, this action
will ground the magnetos out through Wire 18 causing loss of spark to the engine. With the loss of fuel and loss of
spark the engine will shutdown.

Page 26

CIRCUIT CONDITION - STOP:

Section 4

RESET

RESET

TEST

TEST

18

IM2

SP2

IM1

SP1

0 0 44C2211C22

C.B.

0000

222222

44D11D44B

11B

11B

0

11A44A

22

20A

C.B.
20A30A

C.B.

30A

C.B.

30A

C.B.

50A

C.B.

30A

C.B.

0

167

SW1

FSS

LOP

0

15

17

0

17

15

0

0

86

14

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

15

C2-12

0

0

16

SC

BATTERY

BLACK

RED

SC

SM

12V

C2-6

C2-11

C2-9

13

13

SCR

0

0

167

15

15

86

0

14

17

18

13

13

16

86

15

15

22

11

0

44

11

0

22

44

11

0

22

44

17

17

SCR - STARTER CONTACTOR RELAY

SW1 - START-RUN-STOP SWITCH

SSR - START / STOP RELAY

SP2 - SPARK PLUG, CYL. 2

SP1 - SPARK PLUG, CYL. 1

SM - STARTER MOTOR

SC - STARTER CONTACTOR

R1 - 25 OHM, 25W RESISTOR

IM2 - IGNITION MODULE, CYL. 2

FSS - FUEL SHUT OFF SOLENOID

CB1 - 10AMP AUTO RESET BREAKER

LOP - LOW OIL PRESSURE

IM1 - IGNITION MODULE, CYL. 1

GND - GROUND BAR

F1 - 10A FUSE

D2, D3 - ENGINE SHUTDOWN DIODE

BA - BRUSH ASSEMBLY

LEGEND

120/240V

50A

TWISTLOK TWISTLOK

120V/30A

TWISTLOK

120V/30A

DUPLEX

120V 120V

GFCI

30A

120/240V

D2

D3

CB2 - 5AMP AUTO RESET BREAKER
D1 - 600V 12A DIODE

BCR2 - BATTERY CHARGE RECTIFIER

BCR1 - BATTERY CHARGE RECTIFIER, 10A

I.C.T. - IDLE CONTROL TRANSFORMER

SW2 - IDLE CONTROL SWITCH
TB1, TB2 - TERMINAL BLOCK

13

= 12 VDC SUPPLY

= 12 VDC CONTROL

= AC POWER

= GROUND

ENGINE DC CONTROL SYSTEM

With the generator running if the Low Oil Pressure (LOP) closes Wire 86 will be connected to Wire 0 frame
ground. Printed Circuit Board action will open Wire 229 from ground; this action will de-energize the Start-Stop
Relay (SSR). This action will cause a shutdown as described on Page 26.

FAULT SHUTDOWN:

Page 27

Section 5

GO TO PROBLEM 1

(BELOW)

GO TO PROBLEM 2 GO TO PROBLEM 2 GO TO PROBLEM 3GO TO VOLTAGE

REGULATOR

ADJUSTMENT,

PAGE 11

TEST 1 - CHECK NO

LOAD VOLTAGE &

FREQUENCY

If Problem Involves AC Output

VOLTAGE &

FREQUENCY BOTH

HIGH OR LOW

FREQUENCY GOOD -

ZERO OR RESIDUAL

VOLTAGE

ZERO VOLTAGE AND

ZERO FREQUENCY

FREQUENCY GOOD -

VOLTAGE HIGH

OR

VOLTAGE LOW

NO-LOAD VOLTAGE &
FREQUENCY GOOD -

VOLTAGE/FREQUENCY

FALLS OFF UNDER LOAD

Problem 1 - Voltage & Frequency Are Both High or Low

TEST 5 - CHECK

STEPPER MOTOR

CONTROL

GO TO VOLTAGE

REGULATOR

ADJUSTMENT,

PAGE 11

FREQUENCY IS GOOD,

BUT NO-LOAD

VOLTAGE IS HIGH

OR VOLTAGE

IS LOW

TROUBLESHOOTING FLOWCHARTS

INTRODUCTION

The “Flow Charts” in this section may be used in
conjunction with the “Diagnostic Tests” of Section 6.
Numbered tests in the Flow Charts correspond to
identically numbered tests of Section 6.

Problems 1 through 5 apply to the AC generator only.
Beginning with Problem 5, the engine DC control sys-

tem is dealt with.

Page 28

TROUBLESHOOTING FLOWCHARTS

TEST 2 - CHECK

MAIN CIRCUIT

BREAKER

TEST 3 - TEST

EXCITATION

CIRCUIT BREAKER

TEST 4 -

PERFORM FIXED

EXCITATION /

ROTOR AMP

DRAW

TEST 9 - TEST

STATOR

TEST 11 -

EXCITATION

WIRING

TEST 6 - WIRE

CONTINUITY

TEST 8 -

DIODE/RESISTOR

INSULATION

RESISTANCE

TEST PAGE 13

INSULATION

RESISTANCE

TEST PAGE 14

INSULATION

RESISTANCE

TEST PAGE 13

TEST 7 -

FIELD BOOST

TEST 12 -

CHECK
BRUSH

LEADS

TEST 13 -

CHECK
BRUSHES &
SLIP RINGS

TEST 14 -

CHECK ROTOR

ASSEMBLY

REPAIR

OR

REPLACE

BAD

BAD

BAD

BAD

GOOD

GOOD

GOOD

GOOD

GOOD

GOOD

GOOD

GOOD

GOOD

GOOD

BAD

BAD

TEST 10 ­SENSING

LEADS

BAD

BAD

BAD

BAD

BAD

BAD

BAD

REPAIR

OR

REPLACE

REPAIR

OR

REPLACE

REPLACE

VOLTAGE

REGULATOR

REPAIR

OR

REPLACE,

THEN

RETEST

REPAIR

OR

REPLACE,

THEN

RETEST

RESET TO

“ON”

OR REPLACE

IF BAD

GOOD -PROCEED
BAD -PROCEED, REPLACE AFTER TESTS
CONCLUDE

Problem 2 - Generator Produces Zero Voltage or Residual Voltage (2-12 VAC)

D

A

C

B

TEST 9 - TEST

STATOR

Section 5

Page 29

Section 5

TEST 4 -

PERFORM FIXED

EXCITATION /

ROTOR AMP

DRAW

TEST 9 - TEST

STATOR DPE

WINDING

CHECK VOLTMETER

FUSES - VERIFY AMP

METER FUNCTIONS

INSULATION

RESISTANCE

TEST PAGE 14

INSULATION

RESISTANCE

TEST PAGE 13

TEST 14 -

CHECK ROTOR

ASSEMBLY

REPAIR

OR

REPLACE

REPAIR

OR

REPLACE

BAD

GOOD

BAD

BAD

BAD

REPLACE FUSES

- THEN RETEST

Problem 2 - Generator Produces Zero Voltage or Residual Voltage (2-12 VAC)

(continued)

G

E

F

TEST 15 -

CHECK LOAD

VOLTAGE &

FREQUENCY

TEST 16 - CHECK

LOAD WATTS &

AMPERAGE

TEST 2 - CHECK /
STEPPER MOTOR

CONTROL

GO TO PROBLEM 8

REDUCE LOAD

END TEST

GOOD

GOOD

BAD

OVERLOADED

NOT OVERLOADED

Problem 3 - Excessive Voltage/Frequency Droop When Load is Applied

TROUBLESHOOTING FLOWCHARTS

Page 30

Section 5

TEST 17 -

CHECK

BATTERY

CHARGE
OUTPUT

TEST 19 -

CHECK

BATTERY

CHARGE

RECTIFIER

TEST 9 - TEST

STATOR

INSULATION

RESISTANCE

TEST PAGE 13

REPAIR

OR

REPLACE

REPAIR

OR REPLACE

REPLACE

FINISHED

GOOD

GOOD

GOOD

BAD

BAD

BAD

BAD

Problem 4 - No Battery Charge Output

TEST 18 -

CHECK 10A

BATTERY
CHARGE

OUTPUT

TEST 19 -

CHECK

BATTERY

CHARGE

RECTIFIER

TEST 20 -

CHECK 10A

CIRCUIT

BREAKER

TEST 9 - TEST

STATOR

INSULATION

RESISTANCE

TEST PAGE 13

REPAIR

OR

REPLACE

REPLACE

REPAIR

OR REPLACE

REPLACE

FINISHED

GOOD

GOOD

GOOD

GOOD

BAD

BAD

BAD

BAD

BAD

Problem 5 - No 10A Battery Charge Output

TROUBLESHOOTING FLOWCHARTS

Page 31

Section 5

BAD

REPAIR
WIRING

GOOD

BAD

TEST 21 ­CHECK 10
AMP FUSE

TEST 26 - CHECK

STARTER
CONTACTOR
RELAY (SCR)

TEST 27 - CHECK
START-RUN-STOP

SWITCH (SW1)

GOOD

TEST 28 - CHECK
START-RUN-STOP

SWITCH (SW1)

WIRING

TEST 22 - CHECK

BATTERY

& CABLES

TEST 23 - CHECK

VOLTAGE AT

STARTER

CONTACTOR

REPLACE FUSE

FUSE BLOWS

REPAIR OR

REPLACE WIRING

OR SCR

REPAIR OR

REPLACE WIRE 16

REPLACE

BAD

BAD

REPLACE

GO TO PROBLEM 9

GOOD

GOOD

NO VOLTAGE

MEASURED

FUSE BAD

BAD

TEST 24 - CHECK

STARTER

CONTACTOR

GOOD

12 VDC

MEASURED

BAD

RECHARGE OR REPLACE BATTERY

- CLEAN, REPAIR OR REPLACE BAD
CABLE(S)

TEST 25 - CHECK

STARTER MOTOR

REPLACE STARTER

MOTOR IF DEFECTIVE

GOOD

CHECK FOR

MECHANICAL BINDING

OF THE ENGINE OR

ROTOR

Problem 6 - Engine Will Not Crank

TROUBLESHOOTING FLOWCHARTS

Page 32

TROUBLESHOOTING FLOWCHARTS

BAD

BAD

BAD

BAD

PULL OUT

ADJUST AND

RE-TEST

REPAIR

OR REPLACE

FSS

REPAIR

OR

REPLACE

REPAIR

OR

REPLACE

REPAIR

OR REPLACE

REPLACE

REPLACE

OFF

OFF

TURN ON

ON

TURN OFF

REPLACE

PRINTED CIRCUIT

BOARD

GOODGOODGOOD

GOOD

SPARK

GOOD

GOOD

GOOD

GOOD

GOOD

GOOD GOOD

GOOD

GOOD

TEST 29 -

CHECK
SPARK

CHECK

FUEL

SUPPLY

CHECK

FUEL

SHUTOFF

VALVE

VERIFY THAT IDLE

CONTROL SWITCH

IS IN THE “OFF”

POSITION

TEST 38 -

CHECK

FUEL PUMP

PULL CHOKE

FULL OUT

TEST 32 - TEST

START STOP

RELAY (SSR)

TEST 34 - TEST

START STOP

RELAY WIRING

TEST 30 -

CHECK
SPARK
PLUGS

TEST 35 - CHECK AND

ADJUST IGNITION

MAGNETOS

TEST 39 -

CHECK

CARBURETION

TEST 33 - TEST

WIRE 167

TEST 40 - CHECK

VALVE

ADJUSTMENT

CHECK

FLYWHEEL KEY -

SEE TEST 35

TEST 41 - CHECK

ENGINE / CYLINDER

LEAK DOWN TEST /

COMPRESSION TEST

REPLENISH

FUEL

SUPPLY

ADJUST

OR REPLACE

REPAIR OR REPLACE AS NECESSARY
REFER TO ENGINE SERVICE MANUAL

P/N 0E2081 FOR FURTHER ENGINE

SERVICE INFORMATION

BAD

Problem 7 - Engine Cranks But Will Not Start

TEST 5 - CHECK

STEPPER

MOTOR

CONTROL

TEST 32 - CHECK

START STOP
RELAY (SSR)

TEST 36 - CHECK

FUEL SHUTOFF

SOLENOID (FSS)

TEST 31 - REMOVE

WIRE 18 /

SHUTDOWN LEAD

TEST 37 - CHECK

FUEL SHUTOFF

SOLENOID VOLTAGE

DC VOLTAGE

MEASURED AT

TWO PIN

CONNECTOR

FULL OUT

NO

SPARK

BAD

GOOD

BAD

BAD

BAD

BAD

BAD

Section 5

Page 33

Section 5

REPAIR

OR REPLACE

BAD

REPAIR

OR REPLACE

BAD

REPAIR

OR REPLACE

BAD

GOODGOODGOOD

GOOD

TEST 29 -

CHECK

SPARK

CHECK

FUEL

SUPPLY

TEST 38 -

CHECK

FUEL PUMP

CHECK CHOKE
POSITION AND

OPERATION

TEST 30 -

CHECK

SPARK

PLUG

TEST 35 - CHECK AND

ADJUST IGNITION

MAGNETOS

TEST 39 - CHECK

CARBURETION

TEST 40 - CHECK

VALVE

ADJUSTMENT

CHECK

FLYWHEEL KEY -

SEE TEST 35

TEST 41 - CHECK

ENGINE /

CYLINDER LEAK

DOWN TEST /

COMPRESSION

TEST

REPLACE SPARK PLUG

PUSH IN AFTER STARTING

REPLENISH

FUEL

SUPPLY

ADJUST

OR REPLACE

REPAIR OR REPLACE AS NECESSARY

REFER TO ENGINE SERVICE MANUAL P/N

0E2081 FOR FURTHER ENGINE SERVICE

INFORMATION

GOOD

GOOD

GOOD

GOOD

GOOD

ENGINE MISS

IS APPARENT

LOW FUEL

BAD

BAD

Problem 8 - Engine Starts Hard and Runs Rough

ADJUST VALVES

AND RETEST

BAD

BAD

TEST 5 - CHECK

STEPPER

MOTOR

CONTROL

REPLACE SWITCH

BAD

CHECK

ENGINE OIL

LEVEL

TEST 42 - CHECK OIL

PRESSURE SWITCH

AND WIRE 86

TEST 27 - TEST

START-RUN-STOP

SWITCH (SW1)

REPLACE SWITCH

REPLENISH OIL

VERIFY START STOP RELAY (SSR)

IS WIRED PROPERLY

GO TO PROBLEM 8

GOOD

OIL LEVEL O.K.

OIL LEVEL LOW

BAD

Problem 9 - Engine Starts Then Shuts Down

TROUBLESHOOTING FLOWCHARTS

Page 34

GOOD

BAD

TEST 50 - CHECK

WIRE 167

REPLACE

BAD

REPLACE

BAD

REPLACE

BAD

CORRECT

WIRING

BAD

REPLACE

BAD

REPAIR

OR

REPLACE

REPAIR OR REPLACE

WIRE 14

REPAIR

OR

REPLACE

REPAIR

OR

REPLACE

BAD

REPLACE

REPLACE

GOOD

GOOD

GOOD

(WITH HM)

GOOD

(WITHOUT HM)

GOOD

GOOD

GOOD

BAD

BAD

GOOD

GOOD

FUSE BLOWS

UPON

INSTALLATION

CONTINUITY

MEASURED

FUSE BLOWS

WHEN RUNNING

FUSE IS GOOD BUT

BLOWS WHEN PLACED

TO START

VERIFY START-RUN-STOP

SWITCH IS WIRED CORRECTLY

(SEE FIGURE 6-46, pg. 55)

Problem 10 - 10 Amp Fuse (F1) Blowing

INSTALL NEW
10 AMP FUSE

TEST 43 - CHECK

START STOP
RELAY (SSR)

CHECK FUEL

SOLENOID

(TEST 47)

AND STARTER

CONTACTOR RELAY

(TEST 44)

VERIFY BCR1

AND BCR2 ARE

WIRED

CORRECTLY

TEST 19 - CHECK

BATTERY CHARGE

RECTIFIER 2

(BCR2)

TEST 45 - CHECK

WIRE 15

BAD

TEST 49 - CHECK

WIRE 15B

TEST 46 - CHECK
WIRE 14 CIRCUIT

TEST 8 - DIODE /

RESISTOR

TEST 47 - CHECK

FUEL SHUTOFF

SOLENOID (FSS)

TEST 48 - CHECK

HOURMETER (HM)

IF EQUIPPED

Section 5

TROUBLESHOOTING FLOWCHARTS

Page 35

Section 5

ON

GOOD

GOOD

OFF

BAD

BAD

TEST 1 - CHECK

NO-LOAD VOLTAGE

& FREQUENCY

TEST 51 - CHECK

WIRES 11S / 44S

GO TO PROBLEM 2

REPAIR OR REPLACE

CHECK TO SEE IF

RED LED ON

CIRCUIT BOARD IS

“ON”

Problem 11 - Unit Overspeeds

PRODUCING

VOLTAGE

REPLACE

CIRCUIT

BOARD

NO

VOLTAGE

TEST 5 - CHECK

STEPPER MOTOR

OPERATION

REPAIR OR REPLACE

GOOD

BAD

TEST 52 - CHECK

IDLE CONTROL

SWITCH

REPLACE

BAD

Problem 12 - Idle Control “RPM Does Not Decrease”

REPLACE PRINTED

CIRCUIT BOARD

VERIFY THAT

THERE IS NO LOAD

ON THE

GENERATOR

GOOD

TEST 53 - CHECK

IDLE CONTROL

WIRING

GOOD

BAD

TEST 54 - CHECK

IDLE CONTROL

TRANSFORMERS

(ICT)

REPLACE

BAD

REPAIR OR REPLACE

Problem 13 - Idle Control “RPM Does Not Increase When Load Is Applied”

REPLACE
PRINTED

CIRCUIT BOARD

VERIFY THAT WIRE 11 &

WIRE 44 ARE ROUTED

THROUGH IDLE CONTROL

TRANSFORMERS (ICT)

ROUTE THROUGH IDLE

CONTROL TRANSFORMERS

AND RE-TEST

GOOD

GOOD

TEST 55 - CHECK

TR1 & TR2

WIRING

BAD

ADJUST OR REPLACE

BAD

BAD

REPLACE

REPAIR

OR

REPLACE

GOOD

GOOD

BAD

BAD - ENGINE MISS

APPARENT

GOOD

TEST 56 - CHOKE

TEST

TEST 29 - CHECK

SPARK

TEST 30 - CHECK

SPARK PLUG

TEST 35 - CHECK /

ADJUST IGNITION

MAGNETOS

*Acceptable running limits for the engine are between 59-61 Hertz.

ADJUST / RE-TEST

TEST 40 - CHECK /

ADJUST VALVES

Problem 14 - Engine “Hunts” / Erratic Idle

REPLACE

PRINTED

CIRCUIT BOARD

NO

SURGING

STILL

SURGING

TEST 5 - CHECK

STEPPER MOTOR

OPERATION

TEST 39 - CHECK

CARBURETION

GOOD

TROUBLESHOOTING FLOWCHARTS

Page 36

Section 6

240

50A

OFF

ON

00.00

A

A

B

B

50A
C.B.

DIAGNOSTIC TESTS

INTRODUCTION

The “Diagnostic Tests” in this chapter may be per­for med in conjunction with the “Flow Charts” of
Section 5. Test numbers in this chapter correspond to
the numbered tests in the “Flow Charts”.

Tests 1 through 19 are procedures Involving problems
with the generator's AC output voltage and frequency
(Problems 1 through 5 in the “Flow Charts”).

Tests 19 through 54 are procedures involving prob­lems with engine operation (Problems 6 through 14 in
the “Troubleshooting Flow Charts”).

It may be helpful to read Section 2, “Measur ing
Electricity”.

NOTE: Test procedures in this Manual are not nec­essarily the only acceptable methods for diagnos­ing the condition of components and circuits. All
possible methods that might be used for system
diagnosis have not been evaluated. If any diag­nostic method is used other than the method pre­sented in this Manual, the technician must ensure
that neither his personal safety nor the product's
safety will be endangered by the procedure or
method that has been selected.

TEST 1 - CHECK NO-LOAD VOLTAGE AND

FREQUENCY

PROCEDURE:

1. Disconnect or turn OFF all electrical loads connected to the

generator.

2. Set a volt meter to measure AC voltage.

3. Reset all circuit breakers to the on position.

4. Turn the Idle Control switch to OFF.

5. Start the engine and let it stabilize and warm up.

*NOTE: If the generator is not producing AC
Power, loss of governor control may occur caus­ing an overspeed or extremely high RPM condi­tion. If this condition occurs manually control
throttle (60Hz /3600 RPM) to perform test.

6. Place the meter test leads into the 50A outlet. See Figure 6-1.

7. Read the AC voltage.

8. Connect a AC frequency meter as described in Step 6.

9. Read the AC frequency.

RESULTS:

For units rated 60 Hertz, no load voltage and frequen­cy should be approximately 238-242 VAC and 59-61
Hertz. See Flow Chart Problem 1.

TEST 2 - CHECK MAIN CIRCUIT BREAKER

PROCEDURE:
The generator has seven circuit breakers located on

the control panel. If outlets are not receiving power,
make sure the breakers are set to ON or “Closed”.

If a breaker is suspected to have failed, it can be
tested as follows (see Figure 6-7):

1. Set a Volt meter to measure resistance.

2. With the generator shut down, disconnect all wires from the

suspected circuit breaker terminals to prevent interaction.

3. With the generator shut down, connect one meter test lead to

a one terminal of the breaker and the other meter test lead to

the other terminal. See Figure 6-7.

4. Set the breaker to its ON or “Closed” position. The meter should

read CONTINUITY.

5. Set the breaker to its OFF or “Open” position and the meter

should indicate INFINITY.

Figure 6-1. – VOM Test Leads Connected to 50A

Outlet

RESULTS:

1. If the circuit breaker tests good, refer back to the flow chart.

2. If the breaker tests bad, it should be replaced.

Figure 6-7. – 50 Amp Breaker Test Points

Page 37

00.00

C.B.

20/30A

2

162

00.00

R1

D2

4

14

14

4

D2

4

14

WIRE 14

REMOVED

JUMPER LEAD

14

4

R1

Section 6
DIAGNOSTIC TESTS

TEST 4 - FIXED EXCITATION TEST/

ROTOR AMP DRAW

PROCEDURE:

*NOTE: If the generator is not producing AC
Power, loss of governor control may occur caus­ing an overspeed or extremely high RPM condi­tion. If this condition occurs manually control
throttle (60Hz /3600 RPM) to perform test.

1. Unplug the six pin connector at the Voltage Regulator.

2. Disconnect Wire 14 from the Resistor (R1).

Figure 6-8. – 20/30 Amp Breaker Test Points

TEST 3 - TEST EXCITATION CIRCUIT BREAKER

PROCEDURE:

1. With the generator shut down for at least two minutes, locate

the Excitation Circuit Breaker in the control panel. Disconnect

wires from the breaker, to prevent interaction.

2. Set a volt meter to measure resistance.

3. Connect the VOM test probes across the circuit breaker termi

nals. The meter should read CONTINUITY.

RESULTS:

1. If circuit breaker tests bad (meter reads “OPEN”) then proceed

to Test 4 and replace the breaker after completing Test 4.

2. If circuit breaker is good, go on to Test 4.

3. Connect a jumper wire between the removed end of Wire 14

and Wire 4 where it is soldered at the Diode (D1). See Figure

6-10.

-

Figure 6-9. - Testing Excitation Circuit Breaker

Page 38

Figure 6-10. – Jumper Lead From Wire 14 to Diode

4. Set voltmeter to measure AC voltage

5. Disconnect Wire 2 from the Excitation Circuit Breaker and con

-

nect one meter test lead to it. Connect the other meter test lead

to Wire 6 located in the six pin connector previously removed

from the Voltage Regulator. Be careful not to damage the pin

connectors with the test leads. See Figure 6-11.

6. Set Idle control switch to OFF.

7. Start the generator.

8. Measure the output voltage across Wire 2 and Wire 6 and

record the results.

AC Voltage across Wires 2 and 6 = _____________

9. Shutdown the generator.

REGULATOR

VOLTAGE

PIN 6

PIN 5

PIN 4

PIN 3

PIN 2

PIN 1

44S

162

11S

0

4

6

D2

4

14

WIRE 14

REMOVED

14

4

R1

1.5 A

10. Reconnect Wire 2 to the Excitation Circuit Breaker.

11. Connect one meter test lead to Wire 11S located in the six

pin connector previously removed from the Voltage Regulator.

Connect the other meter test lead to Wire 44S located in the six

pin connector previously removed from the Voltage Regulator.

See Figure 6-11. Be careful not to damage the pin connectors

with the test leads.

Figure 6-11. - Voltage Regulator Pin Connector Wire

Number Locations

12. Start the generator.

13. Measure the output voltage across wires 11S and 44S and

record the results.

AC Voltage across Wires 11S and 44S= _________

14. Shutdown the generator.

15. Remove the Jumper lead between Wire 14 and Diode D1.

16. Set the voltmeter to measure DC amperage (10 Amp Range).

Switch the test leads on the meter if required.

Section 6

DIAGNOSTIC TESTS

Figure 6-12. – Measuring Amp Draw

17. Connect the positive meter test lead to Wire 14. Connect the

negative test lead to Wire 4 at Diode D1. See Figure 6-12.

18. Start the generator.

19. Measure the DC Rotor Amp draw and record the results.

Rotor Amp Draw =________________

20. Shutdown the generator.

21. Reconnect the six pin connector.

22. Reconnect Wire 14 to the resistor R1.

RESULTS:
Refer to "TEST 4 RESULTS" chart.

TEST 4 RESULTS

A B C D E F G

VOLTAGE RESULTS
WIRE 2 & 6
EXCITATION WINDING

VOLTAGE RESULTS
WIRE 11S & 44S

ROTOR AMP DRAW

12.5 kW (MODEL 004451-0)

ROTOR AMP DRAW
15 kW (MODEL 004582-0,1)

ROTOR AMP DRAW
15 kW (MODEL 004582-2)

ROTOR AMP DRAW

17.5 kW (MODEL 004583-0)

(MODEL 004986-0)

(MODEL 004987-0)
(MODEL 005209-0)

(MODEL 004987-1)

(MODEL 005308-0)

(MATCH RESULTS WITH LETTER AND REFER TO FLOW CHART – Problem 2 on Pages 29 & 30)

ABOVE
60 VAC

ABOVE

120 VAC

1.8 A

± 20%

1.6 A

± 20%

0.96 A
± 20%

0.89 A
± 20%

ABOVE
60 VAC

BELOW
120 VAC

1.8 A

± 20%

1.6 A

± 20%

0.96 A
± 20%

0.89 A
± 20%

BELOW

60 VAC

ABOVE

120 VAC

1.8 A

± 20%

1.6 A

± 20%

0.96 A
± 20%

0.89 A
± 20%

ZERO OR RESIDUAL VOLTAGE

(2-12 VAC)

ZERO OR RESIDUAL VOLTAGE

(2-12 VAC)

ZERO CURRENT DRAW 2.3 A

ZERO CURRENT DRAW 2.1 A

ZERO CURRENT DRAW 1.5 A

ZERO CURRENT DRAW 1.4 A

BELOW

60 VAC

BELOW

120 VAC

BELOW

60 VAC

BELOW
120 VAC

1.8 A

± 20%

1.6 A

± 20%

0.96 A
± 20%

0.89 A
± 20%

ABOVE
60 VAC

ABOVE

120 VAC

ZERO

CURRENT

DRAW

ZERO

CURRENT

DRAW

ZERO

CURRENT

DRAW

ZERO

CURRENT

DRAW

Page 39

STEPPER
MOTOR

THROTTLE

LINKAGE

FULL THROTTLE CLOSED THROTTLE

RED

EMPTY

ORANGE

BROWN

YELLOW

BLACK

Section 6
DIAGNOSTIC TESTS

TEST 5 - CHECK STEPPER MOTOR CONTROL

PROCEDURE:

1. Remove air cleaner cover to access stepper motor.

2. Physically grab the throttle and verify the stepper motor, linkage

and throttle do not bind in any way, if any binding is felt repair

or replace components as needed. Some resistance should be

felt as the stepper motor moves through it's travel.

3. Physically move the throttle to the closed position by pushing

the throttle down as looking from above.

a. Place the idle control switch to off.
b. Place the start switch to start and watch for

stepper motor movement it should move to the
wide open position during cranking. Once the
unit starts the stepper motor should move the
throttle to a position to maintain 60 Hertz.

Figure 6-2. – Stepper Motor, Linkage and Throttle

Seen From Above

5. If problem continues remove six pin connector from printed cir

cuit board. Set Volt meter to measure ohms. Carefully measure

from the end of the six pin harness as follows:

Figure 6-4. – Six Pin Connector Wire Colors

NOTE: Press down with the meter leads on the
connectors exposed terminals, do not probe into
the connector.

a. Connect one meter lead to Red, connect the

remaining test lead to Orange, approximately 10
ohms should be measured.

b. Connect one meter lead to Red, connect the

remaining test lead to Yellow, approximately 10
ohms should be measured.

c. Connect one meter lead to Red, connect the

remaining test lead to Brown, approximately 10
ohms should be measured.

d. Connect one meter lead to Red, connect the

remaining test lead to Black, approximately 10
ohms should be measured.

e. Connect one meter lead to Red, connect the

remaining test to the stepper motor case. No
resistance should be measured INFINITY or
Open”

See Figure 6-4.

6. Set a voltmeter to measure DC voltage.

-

Figure 6-3. – Throttle Positions

4. If no movement is seen in Step 3 remove the control panel

cover. Verify the six pin connector on the printed circuit board is

seated properly, remove the connector and then replace it and

test again. Verify the switches are correctly set. See Figure 4-1

on Page 16 for positioning.

Page 40

7. Connect the positive meter test lead to Wire 15B at Terminal

Block 1 (TB1). Connect the negative meter test lead to ground.

See Figure 6-5. Place the Start-Run-Stop Switch (SW1) to

START. 12 VDC should be measured. If voltage was measured

proceed to Step 8. If voltage was not measured, proceed to

"RESULTS".

8. Set a voltmeter to measure resistance.

9. Disconnect the J2 connector from the printed circuit board.

Connect one meter test lead to Pin Location J2-1 (Wire 15B.

Connect the other meter test lead to Wire 15B at Terminal

Block 1 (TB1). See Figure 6-6. Continuity should be measured.

Section 6

TERMINAL

BLOCK

(TB1)

12.00

86 15B

167

BLK

0 229

83

BLK

TR2

TR1

TB1

J2 HARNESS CONNECTOR

00.00

86 15B

167

BLK

0 229

83

BLK

TR2

TR1

J2-1 J2-12

MAKE SURE THE TEST
PROBE CONNECTOR IS
MAKING CONTACT
WITH THE CONNECTOR.
DOUBLE CHECK TO
MAKE SURE THAT THE
TIP IS SHARP.

DIAGNOSTIC TESTS

TEST 6 - WIRE CONTINUITY

PROCEDURE:

1. Set a Voltmeter to measure resistance.

2. Remove the six pin connector from the Voltage Regulator.

3. Connect one meter test lead to Wire 0 in the six pin connector

previously removed from the Voltage Regulator. See Figure 6-

11. Be careful not to damage the pin connectors with the test

leads.

3. Connect the other test lead to the ground terminal in the control

panel. The meter should read continuity.

Figure 6-5. – Testing Wire 15B

4. Connect one meter test lead to Wire 162 in the six pin connec

tor previously removed from the Voltage Regulator. See Figure

6-11. Be careful not to damage the pin connectors with the test

leads.

5. Remove Wire 162 from the Excitation Circuit Breaker (CB1).

Connect the other meter test lead to Wire 162. The meter

should read continuity.

RESULTS:
If continuity was NOT measured across each wire,

repair or replace the wires as needed. If continuity
WAS measured refer back to flow chart.

TEST 7 - CHECK FIELD BOOST

PROCEDURE:

1. Set VOM to measure DC voltage.

2. Disconnect the six pin connector from the Voltage Regulator.

3. Disconnect Connector C1. See Page 17 for connector location.

4. Disconnect Wire 16 from the Starter Contactor Relay (SCR).

See Figure 6-13. This will cause the unit not to crank when

placed in the Start position.

-

RESULTS:

1. If the stepper motor fails any part of Step 5 replace the stepper

motor.

2. If Step 7 fails repair or replace Wire 15B between the Start-

Run-Stop Relay (SSR) and Terminal Block TB1.

3. If the stepper motor passes all steps replace the Printed Circuit

Board.

Figure 6-6. – Testing J2-1

5. Connect the positive meter test lead to Wire 4 at the diode

(D1), Wire 4 is soldered to the diode. See Figure 6-14. Connect

the negative meter test lead to the ground terminal.

6. Set the Start-Run-Stop Switch (SW1) to START. Measure the

DC voltage. It should read approximately 12 VDC.

7. Reconnect the Six Pin connector to the Voltage Regulator,

Reconnect the C1 connector, and reconnect Wire 16 to the

Starter Contactor Relay.

RESULTS:

1. If 12 VDC was measured in Step 5 the field boost circuit is

working refer back to the flow chart.

2. If field boost voltage was not measured refer back to the flow

chart.

Page 41

WIRING DIAGRAM

30

86

87a

85

87

85

87a

30

86

87

16

15

17

13

16

R1

D2

4

14

14

4

3.0 vdc

D2

4

14

WIRE 14

REMOVED

14

4

R1

OL

D2

4

14

WIRE 14

REMOVED

14

4

R1

.5 vdc

Section 6
DIAGNOSTIC TESTS

Figure 6-13. – Starter Contactor Relay

Figure 6-14. – Testing Field Boost

PROCEDURE:

1. Set volt meter to the diode test range.

2. Disconnect the six pin connector from the Voltage Regulator.

3. Disconnect Connector C1. See Page 17 for connector location.

4. Disconnect both wires from the Resistor (R1).

5. Connect the positive meter test lead to the top terminal of the

diode (D1). Connect the negative meter test lead to the bottom

of the diode (D1). See Figure 6-15. INFINITY or an open condi

tion should be measured.

Page 42

TEST 8 - DIODE/RESISTOR

Figure 6-15. – Diode Test Step 5

6. Connect the positive meter test lead to the bottom terminal of

the diode (D1). Connect the negative meter test lead to the top

of the diode (D1). Approximately 0.5 Volts should be measured.

Figure 6-16. – Diode Test Step 6

7. Set volt meter to measure resistance.

8. Connect one meter test lead to the top terminal of the diode

(D1). Connect the other meter test lead to the ground terminal.

INFINITY or an open condition should be measured.

9. Connect one meter test lead to one terminal of the resistor

(R1). Connect the other meter lead to the remaining terminal of

-

resistor (R1). See Figure 6-17. Approximately 25 ohms should

be measured.

D2

4

14

WIRE 14

REMOVED

14

4

R1

25 ohm

Figure 6-17. – Diode Test Step 9

PIN

LOCATION

6

PIN

LOCATION

7

PIN

LOCATION

1

PIN

LOCATION

12

2

77A

66A

55A

44S

11S

0

4

77

66

55

6

10. Connect one meter test lead to the top terminal of the resistor

(R1). Connect the other meter test lead to the ground terminal.

INFINITY or an open condition should be measured.

11. Reconnect the six pin connector, reconnect the C1 connector,

reconnect the two wires removed from the resistor (R1).

RESULTS:

1. If the diode or resistor failed any step it should be replaced.

Section 6

DIAGNOSTIC TESTS

Figure 6-18. – C1 Connector, Female Side

9. Connect the meter test leads across Stator leads 2 (Pin 6)

and Stator lead 6 (Pin 7) at the C1 connector female side. See

Figure 6-18. Be careful not to damage the pin connectors with

the test leads, use paper clips - do not force probes into con-

nectors. Normal excitation winding resistance should be read.

10. Connect the meter test leads across Stator leads 66 (Pin 9)

and Stator lead 77 (Pin 10) at the C1 connector female side.

See Figure 6-18. Be careful not to damage the pin connectors

with the test leads, use paper clips - do not force probes into

connectors. Normal 10 Amp battery charge winding resistance

should be read.

TEST 9 - TEST STATOR

PROCEDURE:

1. From the 50 Amp circuit breaker, disconnect Wires 11 and 44.

2. From the 50 Amp receptacle disconnect Wire 22.

3. Disconnect Connector C1. See Page 17 for connector location.

4. Set a voltmeter to measure resistance.

5. Connect the meter test leads across Stator leads 11 and 22.

Normal power winding resistance should be read.

6. Connect the meter test leads across Stator leads 44 and 22.

Normal power winding resistance should be read.

7. Connect the meter test leads across Stator leads 11S (Pin 1)

and Stator lead 44S (Pin 2) at the C1 connector female side.

See Figure 6-18. Be careful not to damage the pin connectors

with the test leads, use paper clips - do not force probes into

connectors. Normal power winding resistance should be read.

8. Connect the meter test leads across Stator leads 66A (Pin 4)

and Stator lead 77A (Pin 5) at the C1 connector female side.

See Figure 6-18. Be careful not to damage the pin connectors

with the test leads, use paper clips - do not force probes into

connectors. Normal battery charge winding resistance should

be read.

Winding Wire

Numbers

Power 11 & 22

Power 44 & 22 0.125 0.088 0.089 0.067

Sensing 11S & 44S 0.25 0.176 0.176 0.134

Excitation 2 & 6 0.576 0.546 1.270 1.010

Battery

Charge

10A

Battery

Charge

66A & 77A 0.132 0.111 0.111 0.103

66 & 77 0.145 0.125 0.125 0.117

Models

004451-0
004986-0

0.125 0.088 0.088 0.067

Models

004582-0,1

004987-0

005209-0

Models

004582-2

004987-1

004583-0

005308-0

Models

* Resistance values In ohms at 20° C. (68° F.). Actual
readings may vary depending on ambient tempera­ture. A tolerance of plus or minus 5% is allowed.

11. Connect the meter test leads across Stator lead 11 and frame

ground. INFINITY should be read.

10. Connect the meter test leads across Stator lead 66A (Pin 4)

and Stator lead 2 (Pin 6) at the C1 connector female side and

frame ground. Be careful not to damage the pin connectors

with the test leads, use paper clips - do not force probes into

connectors. See Figure 6-18. INFINITY should be read.

Page 43

PIN

LOCATION

7

PIN

LOCATION

6

PIN

LOCATION

12

PIN

LOCATION

1

0

4

77

66

55

6

2

77A

66A

55A

44S

11S

Section 6
DIAGNOSTIC TESTS

12. Connect the meter test leads across Stator lead 2 (Pin 6) at

the C1 connector female side and frame ground. Be careful not

to damage the pin connectors with the test leads, use paper

clips - do not force probes into connectors. See Figure 6-18.

INFINITY should be read.

13. Connect the meter test leads across Stator lead 66 (Pin 9) at

the C1 connector female side and frame ground. Be careful not

to damage the pin connectors with the test leads, use paper

clips - do not force probes into connectors. See Figure 6-18.

INFINITY should be read.

14. Connect the meter test leads across Stator leads Wire 11 and

Stator lead 66A (Pin 4) at the C1 connector female side. Be

careful not to damage the pin connectors with the test leads,

use paper clips - do not force probes into connectors. See

Figure 6-18. INFINITY should be read.

15. Connect the meter test leads across Stator leads Wire 11 and

Stator lead 2 (Pin 6) at the C1 connector female side. Be care

ful not to damage the pin connectors with the test leads, use

paper clips - do not force probes into connectors. See Figure

6-18. INFINITY should be read.

16. Connect the meter test leads across Stator leads Wire 11 and

Stator lead 66 (Pin 9) at the C1 connector female side. Be care

ful not to damage the pin connectors with the test leads, use

paper clips - do not force probes into connectors. See Figure

6-18. INFINITY should be read.

17. Connect the meter test leads across Stator lead 66A (Pin 4)

and Stator lead 2 (Pin 6) at the C1 connector female side. Be

careful not to damage the pin connectors with the test leads,

use paper clips - do not force probes into connectors. See

Figure 6-18. INFINITY should be read.

18. Connect the meter test leads across Stator lead 66A (Pin 4)

and Stator lead 66 (Pin 9) at the C1 connector female side. Be

careful not to damage the pin connectors with the test leads,

use paper clips - do not force probes into connectors. See

Figure 6-18. INFINITY should be read.

19. Connect the meter test leads across Stator lead 2 (Pin 6) and

Stator lead 66 (Pin 9) at the C1 connector female side. Be care

ful not to damage the pin connectors with the test leads, use

paper clips - do not force probes into connectors. See Figure

6-18. INFINITY should be read.

RESULTS:
If the stator fails any step replace it, for Steps 1-10

keep in mind resistance values may vary depending
on ambient temperature and calibration of the meter
used. If the stator passes all tests refer back to the
flow chart.

TEST 10 - SENSING LEADS

PROCEDURE:

1. Set a VOM to measure resistance.

2. Disconnect Connector C1. See Page 17 for connector location.

3. Locate the male side of the connector located on the bottom of

the control panel. See Figure 6-19. Connect one meter test lead

to Pin 1 Wire 11S. It may be helpful to connect a small jumper

lead to the individual pin. Connect the other meter test lead to

Wire 11S at Terminal Block 2 (TB2) . See Page 17 for Terminal

Block 2 location. Continuity should be measured.

-

-

Figure 6-19. – C1 Connector, Male Side

4. Locate the male side of the connector located on the bottom

of the control panel. See Figure 6-19. Connect one meter test

lead to Pin 2 Wire 44S. It may be helpful to connect a small

jumper lead to the individual pin. Connect the other meter test

lead to Wire 44S at Terminal Block 2 (TB2). Continuity should

be measured.

5. Unplug the six pin connector at the Voltage Regulator.

6. Connect the one meter test lead to Wire 11S at Terminal

Block 2 (TB2). Connect the other meter test lead to Wire 11S

at the six pin connector previously removed from the Voltage

-

Regulator. See Figure 6-11. Be careful not to damage the pin

connectors with the test leads. Continuity should be measured.

7. Connect the one meter test lead to Wire 44S at Terminal

Block 2 (TB2). Connect the other meter test lead to Wire 44S

at the six pin connector previously removed from the Voltage

Regulator. See Figure 6-11. Be careful not to damage the pin

connectors with the test leads. Continuity should be measured.

RESULTS:

1. If continuity was not measured in any of the steps repair or

replace wire.

Page 44

2. If all steps pass refer back to flow chart.

Section 6

4

0

DIAGNOSTIC TESTS

TEST 11 - EXCITATION WIRING

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Disconnect Connector C1. See Page 17 for connector location.

3. Locate the male side of the connector located on the bottom

of the control panel. See Figure 6-19. Connect one meter

test lead to Pin 6 Wire 2, it may be helpful to connect a small

jumper lead to the individual pin. Disconnect Wire 2 from the

Excitation Circuit Breaker (CB1). Connect the other meter test

lead to Wire 2 . See Page 17 for Excitation Circuit Breaker loca

tion. Continuity should be measured.

4. Unplug the six pin connector at the Voltage Regulator.

5. Locate the male side of the C1 connector located on the bot

tom of the control panel. Connect one meter test lead to Pin

7, Wire 6. It may be helpful to connect a small jumper lead to

the individual pin. Connect the other meter Test lead to Wire 6

located in the six pin connector previously removed from the

Voltage Regulator. Be careful not to damage the pin connectors

with the test leads. Continuity should be measured.

RESULTS:

1. If continuity was not measured in any of the steps repair or

replace wire.

5. Connect one meter test lead across Wire 0 (Pin 12) at the

C1 connector female side. Be careful not to damage the pin

connectors with the test leads, use paper clips - do not force

probes into connectors. Connect the other meter test lead to

Wire 0 at the brush assembly. Continuity should be measured.

If INFINITY is measured repair or replace Wire 0.

6. Unplug the six pin connector at the Voltage Regulator.

7. Locate the male side of Connector C1 located on the bottom

of the control panel. See Figure 6-19. Connect one meter test

lead to Pin 11 Wire 4. Connect the other meter test lead to Wire

-

-

4 at the six pin connector previously removed from the Voltage

Regulator. See Figure 6-11. Be careful not to damage the pin

connectors with the test leads. Continuity should be measured.

If continuity is not measured repair or replace Wire 4 between

the C1 connector and the six-pin Voltage Regulator connector.

8. Connect one meter test lead to Pin 12 Wire 0. See Figure 6-19.

Connect the other meter test lead to the ground terminal in the

control panel. Continuity should be measured. If continuity is

not measured repair or replace Wire 0 between the C1 connec

tor and the ground terminal.

RESULTS:

1. Repair or replace wiring/terminals as needed.

2. If no faults are found refer to flow chart.

-

2. If all steps pass refer back to flow chart.

TEST 12 - CHECK BRUSH LEADS

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Disconnect Connector C1. See Page 17 for connector location.

3. See Figure 6-18. Connect the meter test leads across Wire 4

(Pin 11) and Wire 0 (Pin 12) at the C1 connector female side.

Be careful not to damage the pin connectors with the test

leads, use paper clips - do not force probes into connectors.

Rotor resistance should be measured approximately 7-14

ohms. If resistance is measured proceed to Step 6. If no resis

tance is measured continue.

4. Remove the control panel assembly to access the brushes.

See Figure 6-21. Connect one meter test lead across Wire

4 (Pin 11) at the C1 connector female side. Be careful not to

damage the pin connectors with the test leads, use paper clips

- do not force probes into connectors. Connect the other meter

test lead to Wire 4 at the brush assembly. Continuity should be

measured. If INFINITY is measured repair or replace Wire 4.

-

Figure 6-20. – Brush Leads

TEST 13 - CHECK BRUSHES & SLIP RINGS

PROCEDURE:

1. Gain access to the brushes and slip rings.

Page 45

Section 6

BRUSHES

POSITIVE (+)
TEST LEAD

DIAGNOSTIC TESTS

Figure 6-21. – Brush Location

2. Remove Wire 4 from the positive (+) brush terminal.

3. Remove the ground wire (0) from the negative (-) brush.

4. Remove the brush holder, with brushes.

* Resistance values in ohms at 20° C. (68° F.). Actual readings

may vary depending on ambient temperature. A tolerance of plus

or minus 5% is allowed.

3. Connect the positive (+) meter test lead to the positive (+) slip

ring, the common (-) test lead to a clean frame ground (such as

the Rotor shaft). The meter should read INFINITY.

RESULTS:

1. Replace the Rotor if it fails the test.

2. If Rotor checks good, perform “Rotor Insulation Resistance

Test,” on Page 15.

5. Inspect the brushes for excessive wear, damage, cracks, chip

ping, etc.

6. Inspect the brush holder, replace if damaged.

7. Inspect the slip rings.

a. If slip rings appear dull or tarnished they may be

cleaned and polished with fine sandpaper. DO
NOT USE ANY METALLIC GRIT TO CLEAN
SLIP RINGS. (A 400 grit wet sandpaper is rec­ommended).

b. After cleaning slip rings, blow away any sandpa-

per residue.

RESULTS:

1. Replace bad brushes. Clean slip rings, if necessary.

2. If brushes and rings are good, go to Test 14.

TEST 14 - CHECK ROTOR ASSEMBLY

PROCEDURE:
Gain access to the brushes and slip rings. Disconnect

Wire 4 and Wire 0 from their respective brushes and
remove the brush holder. Then, test the Rotor as fol­lows:

1. Set a voltmeter to measure resistance.

2. Connect the positive (+) meter test lead to the positive (+) slip

ring (nearest the Rotor bearing). Connect the common (-) test

lead to the negative (-) slip ring. Read the resistance of the

Rotor windings, in OHMS.

-

Figure 6-22. – Testing at Slip Rings

TEST 15 - CHECK LOAD VOLTAGE &

FREQUENCY

PROCEDURE:
Perform this test in the same manner as Test 1, but

apply a load to the generator equal to its rated capac­ity. With load applied check voltage and frequency.

Frequency should not drop below about 59 Hertz with
the load applied.

Voltage should not drop below about 235 VAC with
load applied.

RESULTS:

1. If voltage and/or frequency drop excessively when the load is

applied, go to Test 16.

2. If load voltage and frequency are within limits, end tests.

TEST 16 - CHECK LOAD WATTS & AMPERAGE

ROTOR RESISTANCE *

MODEL: OHMS

004451-0 004986-0 7.01Ω

004582-0,1 004987-0 005209-0 7.71Ω

004582-2 004987-1 13.1Ω

004583-0 005308-0 14.2Ω

Page 46

PROCEDURE:
Add up the wattages or amperages of all loads pow-

ered by the generator at one time. If desired, a clamp­on ammeter may be used to measure current flow.
See “Measuring Current” on Page 7.

RESULTS:

1. If the unit is overloaded, reduce the load.

Section 6

66A

15

BCR2

77A

15

2.0 a

66

BCR1

77

13A

5.0 a

DIAGNOSTIC TESTS

2. If load is within limits, but frequency and voltage still drop

excessively, refer back to Flow Chart.

TEST 17 - CHECK BATTERY CHARGE

OUTPUT

PROCEDURE:

1. Disconnect Wire 15 (center terminal) from the Battery Charge

Rectifier 2 (BCR2), which is located under BCR1. They are

stacked. See Page 17 for BCR2 location.

Figure 6-23. – Testing BCR2

2. Set a voltmeter to measure DC Amps. Connect the positive (+)

test lead to the center terminal of the Battery Charge Rectifier.

Connect the negative (-) test lead to Wire 15 previously discon-

nected.

3. Start the generator. The amp reading on the voltmeter should

be approximately 0.6 Amps. Apply full load to the generator.

The amp reading should increase to approximately 2 Amps.

RESULTS:

1. If amperage was measured between 0.6 to 2 Amps in Step 2

and Step 3, the charging system is working.

2. If no amperage was measured, check the voltmeter fuses and

verify the functioning of the Amp Meter. If DC Amp Meter is

good and no current is measured refer to flow chart.

2. Set a voltmeter to measure DC Amperage. Connect the posi-

tive (+) test lead to the center terminal of the Battery Charge

Rectifier. Connect the negative (-) test lead to Wire 13A previ-

ously disconnected. See Figure 6-24.

Figure 6-24. – Testing BCR1

3. Start the generator. The amp reading on the voltmeter should

be approximately 0.2 Amps. Apply full load to the generator.

The amp reading should increase. It will depend upon the state

of charge of the battery as to how high current will get. Normal

ranges at full load can be 3-7 amps, but can get as high as 10

amps.

RESULTS:

1. If amperage was measured between 0.2 to 10 Amps in Step 2

and Step 3, the charging system is working.

2. If no amperage was measured, check the voltmeter fuses and

verify the functioning of the Amp Meter. If DC Amp Meter is

good and no current is measured refer to flow chart.

TEST 19 - CHECK BATTERY CHARGE

RECTIFIER (BCR2)

PROCEDURE:

1. Disconnect all wires from the Battery Charge Rectifier.

TEST 18 - CHECK 10 AMP BATTERY CHARGE

OUTPUT

PROCEDURE:

NOTE: The battery charge cable must be connect­ed to the 12 VDC panel receptacle and be charging
a separate battery to perform this test.

1. Disconnect Wire 13A (center terminal) from the Battery Charge

Rectifier 1 (BCR1), which is located on top of BCR2 they are

stacked. See Page 17 for BCR1 location.

2. Set the VOM to the Diode Test range. Connect the negative (-)

test lead to the center terminal of the BCR. Connect the posi

tive (+) test lead to an outer terminal. The meter should mea-

sure approximately 0.5 volts. Now connect the positive test lead

to the other outer terminal. Again, the meter should measure

approximately 0.5 volts.

3. Connect the positive (+) test lead to the center terminal of the BCR.

Connect the negative (-) test lead to an outer terminal. The meter

should measure INFINITY. Connect the negative test lead to the

other outer terminal. INFINITY should once again be measured.

Page 47

-

66

13A

77

66A

15

77A

BCR1 BCR2

10A CIRCUIT BREAKER (CB1)

13A

00.00

15A

Section 6
DIAGNOSTIC TESTS

Short to Ground:

4. Set the VOM to measure resistance. Connect the positive (+)

test lead to the case housing of the BCR. Connect the negative

(-) test lead to an outer terminal. INFINITY should be mea

sured. Now connect the negative test lead to the BCR center

terminal. INFINITY should be measured. Next, connect the

negative test lead to the remaining outer BCR terminal. Once

again INFINITY should be measured.

Figure 6-25. – Battery Charge Rectifier

-

Figure 6-26. – Testing 10 Amp Breaker

TEST 21- CHECK 10 AMP FUSE

RESULTS:

1. If any of the previous steps has failed, replace the Battery

Charge Rectifier.

2. If the BCR tests good, refer back to the flow chart.

TEST 20 - CHECK 10 AMP CIRCUIT BREAKER

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Locate the 10 Amp circuit breaker (CB1) in the control panel.

See Page 17 for Circuit breaker location.

3. Disconnect Wire 15A and Wire 13A from the circuit breaker.

4. Connect one meter test lead to one terminal of the circuit

breaker. Connect the other meter test lead to the remaining

terminal on the circuit breaker. Continuity should be measured.

See Figure 6-26.

RESULTS:

1. If continuity was measured the breaker is good refer back to the

flow chart.

2. If INFINITY or a open condition was measured replace the

circuit breaker.

Figure 6-27. – 10 Amp Fuse (Located in Rear of

Control Panel)

PROCEDURE:
Push in on fuse holder cap and turn counterclockwise.

Then, remove the cap with fuse. Inspect the Fuse.

RESULTS:
If the Fuse element has melted open, replace the

Fuse with an identical size fuse. If Fuse is good, refer
back to flow chart.

TEST 22- CHECK BATTERY & CABLES

PROCEDURE:

1. Inspect the battery cables and battery posts or terminals for

corrosion or tightness. Measure the voltage at the terminal of

the Starter Contactor and verify 11-12 volts DC is available to

the generator during cranking. If voltage is below 11 volts DC,

Page 48

measure at the battery terminals during cranking. If battery

CONNECTING

DIAGRAM

BATTERY

12V

STARTER

SWITCH

PERMANENT MAGNET

30

50

16

STARTER

CONTACTOR

STARTER

MOTOR

STEP 2

TEST POINT

STEP 1

TEST POINT

voltage is below 11 volts DC, recharge/replace battery. If bat-

tery or cables are still suspected, connect an alternate battery

and cables to the generator and retest.

2. Use a battery hydrometer to test the battery for (a) state of

charge and (b) condition. Follow the hydrometer manufacturer's

instructions carefully.

RESULTS:

1. Clean battery posts and cables as necessary. Make sure bat-

tery cables are tight.

2. Recharge the battery, if necessary.

3. Replace the battery, if necessary.

4. If battery is good, but engine will not crank, refer back to Flow

Charts.

TEST 23 - CHECK VOLTAGE AT STARTER

CONTACTOR (SC)

Section 6

DIAGNOSTIC TESTS

Figure 6-28. – The Starter Contactor (SC)

PROCEDURE:

1. Set voltmeter to measure DC voltage.

2. Disconnect Wire 16 from the Starter Contactor located on the

3. Connect the positive meter test lead to Wire 16 previous

4. Place the Start-Run-Stop Switch to Start. 12 VDC should be

5. Reconnect Wire 16 to the Starter Motor.

RESULTS:
Refer back to flow chart.

TEST 24 - CHECK STARTER CONTACTOR (SC)

PROCEDURE:

1. Carefully inspect the starter motor cable that runs from the

Starter motor.

ly removed. Connect the negative meter test lead to frame

Ground.

measured.

Battery to the Starter Motor. Cable connections should be

clean and tight. If connections are dirty or corroded, remove

cable and clean cable terminals and studs. Replace any cable

that is defective or badly corroded. Set the voltmeter to mea-

sure DC voltage. Connect the positive (+) meter test lead to

the Starter Contactor stud that the battery cable is connected

to. Connect the negative (-) meter test lead to a clean frame

ground. Battery voltage should be measured (see Figure 6-28,

STEP 1 TEST POINT).

2. Set the voltmeter to measure DC voltage. Connect the positive

(+) meter test lead to the Starter Contactor stud that has the

small jumper wire connected to the Starter. Connect the nega-

tive (-) meter test lead to a clean frame ground. Set the Start-

Stop Switch to START. Battery voltage should be measured

-

(see Figure 6-28, STEP 2 TEST POINT).

RESULTS:

1. If battery voltage was not measured in Step 1, repeat Test 22.

2 If battery voltage was measured in Step 1, but not in Step 2,

replace the Starter Contactor.

4. If battery voltage was measured in Step 2 but the engine still

does not crank, refer back to the Flow Chart.

TEST 25 - CHECK STARTER MOTOR

CONDITIONS AFFECTING STARTER MOTOR
PERFORMANCE:

1. A binding or seizing condition in the Starter Motor bearings.

2. A shorted, open or grounded armature.

a. Shorted, armature (wire insulation worn and

wires touching one another). Will be indicated by
low or no RPM.

b. Open armature (wire broken) will be indicated

by low or no RPM and excessive current draw.

c. Grounded armature (wire insulation worn and

wire touching armature lamination or shaft). Will
be indicated by excessive current draw or no
RPM.

Page 49

PINION

Section 6
DIAGNOSTIC TESTS

3. A defective Starter Motor switch.

4. Broken, damaged or weak magnets.

5. Starter drive dirty or binding.

PROCEDURE:
The battery should have been checked prior to this

test and should be fully charged.

Set a voltmeter to measure DC voltage (12 VDC).
Connect the meter positive (+) test lead to the Starter
Contactor stud which has the small jumper wire con­nected to the Starter. Connect the common (-) test
lead to the Starter Motor frame.

Set the Start-Stop Switch to its START position and
observe the meter. Meter should Indicate battery volt­age, Starter Motor should operate and engine should
crank.

RESULTS:

1. If battery voltage is indicated on the meter but Starter Motor did

not operate, remove and bench test the Starter Motor (see fol-

lowing test).

2. If battery voltage was indicated and the Starter Motor tried to

engage (pinion engaged), but engine did not crank, check for

mechanical binding of the engine or rotor.

NOTE: If a starting problem is encountered, the
engine itself should be thoroughly checked to
eliminate it as the cause of starting difficulty. It is
a good practice to check the engine for freedom
of rotation by removing the spark plugs and turn­ing the crankshaft over slowly by hand, to be sure
it rotates freely.

CHECKING THE PINION:
When the Starter Motor is activated, the pinion gear

should move and engage the flywheel ring gear. If the
pinion does not move normally, inspect the pinion for
binding or sticking.

Figure 6-30. – Check Pinion Gear Operation

TOOLS FOR STARTER PERFORMANCE TEST:
The following equipment may be used to complete a

performance test of the Starter Motor:

• A clamp-on ammeter.

• A tachometer capable of reading up to 10,000 rpm.

• A fully charged 12 volt battery.

MEASURING CURRENT:
To read the current flow, in AMPERES, a clamp-on

ammeter may be used. This type of meter indicates
current flow through a conductor by measuring the
strength of the magnetic field around that conductor.

WARNING!: DO NOT ROTATE ENGINE WITH

*

ELECTRIC STARTER WITH SPARK PLUGS
REMOVED. ARCING AT THE SPARK PLUG
ENDS MAY IGNITE THE GASOLINE VAPOR
EXITING THE SPARK PLUG HOLE.

Figure 6-29. – Starter Motor (SM)

Page 50

Figure 6-31. – Clamp-On Ammeter

TACHOMETER:
A tachometer is available from your Generac Power

Systems source of supply. Order as P/N 042223. The
tachometer measures from 800 to 50,000 RPM (see
Figure 6-32).

Figure 6-32. – Tachometer

METAL STOCK
1/4" THICK STEEL

12"

1.0"

4"

2"

2.625"

3.5"

0.5"

0.5"

DRILL TWO HOLES — 1/2"
FOR STARTER
MOUNTING BRACKET

DRILL TWO HOLES — 1/2"
FOR MOUNTING TACHOMETER
TAP FOR 1/4-20 NC SCREWS

STARTER

CONTACTOR

STARTER

MOTOR

TACHOMETER

12 VOLT

BATTERY

CLAMP ON

AMP METER

VISE

TEST BRACKET:
A starter motor test bracket may be made as shown

in Figure 6-33.

Section 6

DIAGNOSTIC TESTS

REMOVE STARTER MOTOR:
It is recommended that the Starter Motor be removed

from the engine when testing Starter Motor perfor­mance. Assemble starter to test bracket and clamp
test bracket in vise (Figure 6-34).

TESTING STARTER MOTOR:

1. A fully charged 12 volt battery is required.

2. Connect jumper cables and clamp-on ammeter as shown in

3. With the Starter Motor activated (jump the terminal on the

Figure 6-33. – Test Bracket Dimensions

Figure 6-34.

Starter Contactor to battery voltage), note the reading on the

clamp-on ammeter and on the tachometer (rpm).

Figure 6-34 – Testing Starter Motor Performance

Note: Take the reading after the ammeter and
tachometer are stab iliz ed, approximately 2-4
seconds.

4. A starter motor in good condition will be within the following

specifications:

Minimum rpm 4500

Maximum Amps 50

Note: Nominal amp draw of starter in generator is
60 amps.

TEST 26 - TEST STARTER CONTACTOR

RELAY (SCR)

PROCEDURE:

1. Set voltmeter to measure DC voltage.

2. Remove Wire 15 from the Starter Contactor Relay (SCR).

Connect the positive meter test lead to Wire 15 previous

ly removed. Connect the negative meter test lead to frame

Ground. 12 VDC should be measured. Reconnect Wire 15 to

the SCR. If 12 VDC is NOT measured on Wire 15 Stop Testing

and repair or replace Wire 15 between the Fuse (F1) and the

SCR.

-

3. Remove Wire 13 from the Starter Contactor Relay (SCR).

Connect the positive meter test lead to Wire 13 previous

ly removed. Connect the negative meter test lead to frame

Page 51

-

Section 6

85

87a

30

86

SCR

87

16

15

17

13

00.00

167

STOP

0

15

15

17

4

5

6

1

2

3

RUN

START

0

DIAGNOSTIC TESTS

Ground. 12 VDC should be measured. Reconnect Wire 13 to

the SCR. If 12 VDC is NOT measured on Wire 13 Stop Testing

and repair or replace Wire 13 between the Starter Contactor

(SC) and the Starter Contactor Relay (SCR).

Note: Jumper leads may be used if necessary.

4. Set voltmeter to measure resistance.

5. Remove Wire 13, Wire 16, and Wire 17 from the Starter

Contactor Relay (SCR)

6. Connect the meter leads across Terminal 87 and Terminal 30 of

the SCR. See Figure 6-35.

CONDITION TERMINALS RESULT

STOP 5,4 OPEN

STOP 5,6 CLOSED

STOP 2,1 OPEN

STOP 2,3 CLOSED

RUN ALL CONDITIONS OPEN

START 5,4 CLOSED

START 5,6 OPEN

START 2,1 CLOSED

START 2,3 OPEN

Figure 6-35. – Starter Contactor Relay Test

7. Connect a jumper wire from Terminal 85 to ground. The relay

should energize and the voltmeter should read continuity. See

Figure 6-35.

8. Reconnect all Wires.

RESULTS:
If continuity was not measured in Step 7 replace the

Starter Contactor Relay. If all steps passed refer back
to flow chart.

TEST 27 - CHECK START-RUN-STOP SWITCH

(SW1)

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Remove all wires from the Start-Run-Stop Switch (SW1).

3. Using the chart below ohm out the Start-Run-Stop Switch.

Connect one meter test lead to one terminal and the other meter

test lead to the other terminal. With meter leads connected acti

vate the switch to Start, Stop or Run and follow the chart.

4. Reconnect all wires to the switch.

Page 52

Figure 6-36. – Start-Run-Stop Switch (SW1)

RESULTS:
If the switch fails any part of the test procedure

replace the switch.

TEST 28 - CHECK START-RUN-STOP SWITCH

(SW1) WIRING

PROCEDURE:

1. Set voltmeter to measure resistance.

2. Remove Wire 17 from the Starter Contactor Relay (SCR).

Connect one meter test lead to Wire 17. Remove Wire 17 from

the Start-Run-Stop Switch (SW1). Connect the other meter test

lead to wire 17. Continuity should be measured.

3. Remove both Wire 0 from the Start-Run-Stop switch (SW1) it is

located in two positions on the switch. Connect one meter test

lead to one Wire 0 and connect the other meter test lead to the

other Wire 0. Continuity should be measured.

4. Remove Wire 0 from the Start-Run-Stop switch (SW1) it is

­located in two positions on the switch. Connect one meter test

lead to one Wire 0 and connect the other meter test lead to

frame ground. Continuity should be measured.

5. Set voltmeter to measure DC voltage.

SET PLUG GAP AT 0.040 inch

(1.016 mm)

6. Remove Wire 15 from the Start-Run-Stop Switch (SW1).

Connect the positive meter test lead to Wire 15. Connect the

negative meter test lead to frame ground. 12 VDC should be

measured.

RESULTS:
Repair or replace any wiring that did not have continu-

ity.
If voltage was not measured in Step 6 repair wiring

between the Starter Contactor Relay (SCR) and the
Start-Run-Stop Switch (SW1).

If all steps passed repair or replace Wire 16 between
the Starter Contactor (SC) and the Starter contactor
Relay (SCR).

TEST 29 - CHECK IGNITION SPARK

PROCEDURE:
A commercially available spark tester may be used

to test the engine ignition system. One can also be
purchased from Generac Power Systems (Part No.
0C5969).

1. Disconnect a high tension lead from a spark plug.

2. Attach the high tension lead to the spark tester terminal.

3. Ground the spark tester clamp by attaching to the cylinder

head (see Figure 6-37).

4. Crank the engine rapidly. Engine must be cranking at 350 rpm

or more. If spark jumps the tester gap, you may assume the

ignition system is working properly. Repeat on remaining cylin

der spark plug.

xxxxxxxxxxxxxxxxxxxxxxxxxx

Figure 6-38. – Checking Engine Miss

RESULTS:
Refer back to the Flow Chart

DIAGNOSTIC TESTS

TEST 30 - CHECK SPARK PLUGS

PROCEDURE:
Remove spark plugs. Clean with a commercial sol-

vent. DO NOT BLAST CLEAN SPARK PLUGS.
Replace spark plugs if badly fouled, if ceramic is
cracked, or if badly worn or damaged. Set gap to

0.040 inch (1.016 mm). Use a Champion RC14YC (or
equivalent) replacement spark plug.

-

Section x

Section 6

5. If spark jumps the tester gap intermittently, the problem may be

in the Ignition Magneto.

Figure 6-37. – Testing Ignition System

Figure 6-39. – Setting Spark Plug Gap

RESULTS:

1. Clean and regap or replace sparks plug as necessary.

2. Refer back to the Flow Chart.

Page 53

Page 53

WIRE 18

SHUTDOWN

LEAD

SSR

15B

1413

9 10 12

5

1 2

6

4

8

229

0

18

14

15

15

15

SSR

15B

1413

9 10 12

5

1 2

6

4

8

229

0

18

14

TEST POINTS A

TEST POINTS B

TEST POINTS C

15

15

15

Section 6
DIAGNOSTIC TESTS

TEST 31 - REMOVE WIRE 18 / SHUTDOWN

LEAD

PROCEDURE:

1. Disconnect Wire 18 from the Stud located above the oil cooler

that extends out From the shrouding.

2. Perform Test 29 again checking for Spark.

RESULTS:
Refer back to Flow Chart.

leads across TEST POINTS B INFINITY should be measured.

Connect meter test leads across TEST POINTS C. INFINITY

should be measured (See Figure 6-42). If the SSR fails any test

replace it.

6. Remove Wire 229 from the SSR. Connect a jumper lead

from the terminal of the SSR that Wire 229 was just removed

from and to frame ground. The relay should energize closed.

Set a voltmeter to measure resistance. Connect meter test

leads across TEST POINTS A INFINITY should be measured.

Connect meter test leads across TEST POINTS B continuity/

closed should be measured. Connect meter test leads across

TEST POINTS C continuity/closed should be measured. See

Figure 6.43. If the SSR fails any test replace it.

RESULTS:
Refer to Flow Chart.

Figure 6-40. – Wire 18

TEST 32 - TEST START STOP RELAY (SSR)

PROCEDURE:

1. Set a voltmeter to measure DC voltage.

2. Remove Wire 15 from Terminal 13 on the Start Stop Relay

(SSR). Connect the positive meter test lead to Wire 15 previ

ously removed. Connect the negative meter test lead to frame

ground. 12 VDC should be measured, if it is proceed to Step 3.

If 12 VDC is not measured repair or replace Wire 15 between

the SSR and the Battery Charge Rectifier 2 (BCR2).

3. With Wire 15 reconnected to the SSR remove Wire 229 from

the SSR. Connect a jumper lead from the terminal of the SSR

that Wire 229 was just removed from and to frame ground. See

Figure 6-43. The relay should energize closed, visually inspect

it to see if it closes. If the relay energizes closed proceed to

Step 4. If the relay does not energize closed replace it.

4. Remove Wire 0, Wire 18, Wire 15, Wire 15B, Wire 15, and Wire

14. See Figure 6-42.

5. Set a voltmeter to measure resistance. Remove jumper lead

from Step 3. Connect meter test leads across TEST POINTS

A continuity/closed should be measured. Connect meter test

Figure 6-41. – Start Stop Relay (SSR)

-

Figure 6-42. – Start Stop Relay (SSR) Not Energized

Page 54

SSR

15B

1413

9 10 12

5

1 2

6

4

8

229

0

18

14

TEST POINTS A

TEST POINTS B

JUMPER LEAD

ADDED TO GROUND

TEST POINTS C

15

15

15

Figure 6-43. – Start Stop Relay (SSR) Energized

J2 HARNESS CONNECTOR

12 vdc

J2-1 J2-12

MAKE SURE THE TEST
PROBE CONNECTOR IS
MAKING CONTACT
WITH THE CONNECTOR.
DOUBLE CHECK TO
MAKE SURE THAT THE
TIP IS SHARP.

TERMINAL

BLOCK

(TB1)

12 vdc

86 15B

167

BLK

0 229

83

BLK

TR2

TR1

12 vdc

167

STOP

0

15

15

17

4

5

6

1

2

3

RUN

START

STEP 4

STEP 5

0

Section 6

DIAGNOSTIC TESTS

3. Connect the positive test lead to Wire 167 at Terminal Block 1

(TB1). Connect the negative meter test lead to frame ground.

Place the Start-Run-Stop Switch (SW1) to start. 12 VDC

should be measured. If 12 VDC is measured, replace Wire 167

between TB1 and the J2 connector. If 12 VDC is not measured

continue testing.

PROCEDURE:

1. Set a voltmeter to measure DC voltage.

2. Remove the J2 connector from the circuit board. Connect the

positive meter test lead to Pin Location J2-5, Wire 167 on the

removed harness connector. See Figure 6-44 Connect the

negative meter test lead to frame ground. Place the Start-Run-

Stop switch (SW1) to start. The engine will crank and 12 VDC

should be measured. If 12 VDC is measured, stop testing. If 12

VDC is not measured continue testing.

Figure 6-44. – Test Wire 167, Step 2

TEST 33 - TEST WIRE 167

Figure 6-45. – Test Wire 167, Step 3

4. Connect the positive test lead to Wire 167 with it connected at

the Start Run Stop Switch (SW1). Connect the negative meter

test lead to frame ground. Place the Start-Run-Stop Switch

(SW1) to start. 12 VDC should be measured. If 12 VDC is mea-

sured, repair or replace Wire 167 between SW1 and the TB1. If

12 VDC is not measured continue testing.

Figure 6-46. – Test Wire 167, Steps 4 & 5

5. Connect the positive meter test to Wire 15 at SW1. See Figure

6-46. Connect the negative meter test lead to frame ground.

12 VDC should be measured. If 12 VDC is measured, replace

SW1. If 12 VDC is not measured repair or replace wire 15

between SW1 and the Starter Contactor Relay (SCR).

Page 55

1.0 vdc

SSR

15B

1413

9 10 12

5

1 2

648

229

0

18

14

15

15

15

TB1

J2 HARNESS CONNECTOR

00.00

86 15B

167

BLK

0 229

83

BLK

TR2

TR1

J2-1 J2-12

MAKE SURE THE TEST
PROBE CONNECTOR IS
MAKING CONTACT
WITH THE CONNECTOR.
DOUBLE CHECK TO
MAKE SURE THAT THE
TIP IS SHARP.

Section 6
DIAGNOSTIC TESTS

TEST 34 - TEST START STOP RELAY WIRING

PROCEDURE:

1. Set voltmeter to the diode test range.

2. Disconnect Wire 229 from the Start Stop Relay (SSR).

3. Connect the positive meter test lead to Wire 229 previous

ly removed. Connect the negative meter test lead to frame

ground. See Figure 6-47. Place the Start-Run-Stop Switch to

the start position. The meter should read approximately 1.0

VDC. If the correct voltage is indicated, stop testing.

-

Figure 6-48. – Testing Wire 229 Between J2

Connector and Terminal Block 1 (TB1)

Figure 6-47. – Testing Wire 229 to Ground

4. Set voltmeter to measure resistance.

5. If voltage was not measured in Step 3 connect one meter test

lead to Wire 229 removed from the SSR. Connect the other

meter test lead to Wire 229 at the Terminal Block 1 (TB1).

Continuity should be measured. If continuity is not measured

repair or replace Wire 229 between SSR and TB1. Remove the

J2 connector the printed circuit board. Connect one meter test

lead to pin location J2-8 (Wire 229) connect the other meter

test lead to Wire 229 at TB1. See Figure 6-48. Be careful not

to damage the pin connectors with the test leads. Continuity

should be measured. If continuity is not measured repair or

replace Wire 229 between the J2 connector and TB1.

RESULTS:

1. If Step 3 passed refer to Flow Chart.

2. If Step 3 failed and Step 5 passed replace the printed circuit

board.

Page 56

TEST 35 - CHECK AND ADJUST IGNITION

MAGNETOS

PROCEDURE:

1. See Figure 6-49. Rotate the flywheel until the magnet is under

the module (armature) laminations.

2. Place a 0.008-0.012 inch (0.20-0.30mm) thickness gauge

between the flywheel magnet and the module laminations.

3. Loosen the mounting screws and let the magnet pull the mag

neto down against the thickness gauge.

4. Tighten both mounting screws.

5. To remove the thickness gauge, rotate the flywheel.

6. Repeat the above procedure for the second magneto.

7. Repeat Test 29 and check for spark across the spark tester

gap.

8. If air gap was not out of adjustment, remove engine ground

harness from magnetos. Repeat Test 29. If sparking now occurs

replace engine ground harness.

-

Section 6

0.008-0.012" GAUGE
(0.203-0.304 mm)

MAGNETO

FUEL PUMP

FUEL TO
CARBURETOR

FUEL FROM TANK

PULSE LINE

DIAGNOSTIC TESTS

9. Now check the flywheel magnet by holding a screwdriver at the

extreme end of its handle and with its point down. When the tip

of the screwdriver is moved to within 3/4 inch (19mm) of the

magnet, the blade should be pulled in against the magnet.

10. Now check the flywheel key. The flywheel’s taper is locked on

the crankshaft taper by the torque of the flywheel nut. A keyway

is provided for alignment only and theoretically carries no load.

Note: If the flywheel key becomes sheared or even
partially sheared, ignition timing can change.
Incorrect timing can result in hard starting or fail­ure to start.

RESULTS:
If sparking still does not occur after adjusting the

armature air gap, testing the ground wires and per­forming the basic flywheel test, replace the ignition
magneto(s).

TEST 37: TEST FUEL SHUTOFF SOLENOID

VOLTAGE

PROCEDURE:

1. Set a voltmeter to measure DC voltage.

2. Dis con nect the two pin connector from the Fuel Shutoff

Solenoid (FSS).

3. Connect the positive meter test lead to the red wire. Connect

the negative meter test lead to the black wire. Place the Start-

Run-Stop switch (SW1) to START. During cranking, 12 VDC

should be measured. If DC voltage is not measured continue

testing.

4. Set a voltmeter to measure resistance.

5. Connect one meter test lead to the black wire. Connect the

other meter test lead to frame ground. Continuity should be

measured. If continuity is not measured repair or replace the

black ground wire or correct poor ground connection.

6. Set a voltmeter to measure DC voltage.

7. Remove Wire 14 from the Start-Stop Relay (SSR). Refer to

Figure 6-41 on Page 54. Connect the positive meter test lead

to the terminal of the SSR that Wire 14 was just removed.

Connect the negative meter test lead to frame ground. Place

the Start-Run-Stop Switch (SW1) to the start position. 12 VDC

should be measured. If 12 VDC is measured repair or replace

Wire 14 between the SSR and Resistor 1 or between Resistor

1 and the FSS.

Figure 6-49. – Setting Ignition Magneto (Armature)

TEST 36 - TEST FUEL SHUTOFF SOLENOID

PROCEDURE

1. Disconnect Wire 16 from the Starter Contactor (SC) located on

the starter motor.

2. Remove the air cleaner cover.

3. Place the Star t-Run-Stop Switch (SW1) to STOP then to

START. When SW1 is activated a click should be heard and

or activation of the Fuel Shutoff Solenoid should be felt. It can

then be assumed that the Fuel Shutoff Solenoid is functioning.

RESULTS:
Refer to flow chart.

Air Gap

(FSS)

RESULTS:
Refer to flow chart.

TEST 38 - CHECK FUEL PUMP

Figure 6-50. – Fuel Pump and Fuel Lines

Page 57

FEELER GAUGE

ALLEN WRENCH

Section 6
DIAGNOSTIC TESTS

PROCEDURE:

1. Remove the fuel line from the fuel filter on the inlet side of the

carburetor. Use a suitable catch can to catch fuel.

2. Crank the engine over, fuel should flow from the fuel line. If fuel

does not flow, verify that fuel is available to the pump. If fuel is

available to the pump inspect the fuel filter, pulse line, and or

replace the fuel pump.

RESULTS:
Refer to flow chart.

TEST 39 - CHECK CARBURETION

PROCEDURE:
Before making a carburetion check, be sure the fuel sup-

ply tank has an ample supply of fresh, clean gasoline.
Check that all shutoff valves are open and fuel flows

freely through the fuel line.
Make sure the choke operates properly.
If the engine will not start, remove and inspect the spark

plug. If the spark plug is wet, look for the following:

• Overchoking.

• Excessively rich fuel mixture.

• Water in fuel.

• Intake valve stuck open.

• Needle/float stuck open.
If the spark plug is dry look for the following:

• Leaking carburetor mounting gaskets.

• Intake valve stuck closed.

• Inoperative fuel pump.

• Plugged fuel filter(s).

• Varnished carburetor

If the engine starts hard or will not start, look for the
following:

• Physical damage to the AC generator. Check the
Rotor for contact with the Stator.

• Starting under load. Make sure all loads are discon
nected or turned off before attempting to crank and
start the engine.

• Check that the choke is working properly.

1. Remove fuel line at carburetor and ensure that there is an

adequate amount of fuel entering the carburetor.

2. Remove the float bowl and check to see if there is any foreign

matter in bottom of carburetor bowl.

3. The float is plastic and can be removed for access to the

needle so it can be cleaned.

4. With all of this removed carburetor cleaner can be used to

clean the rest of the carburetor before reassembly.

5. After cleaning carburetor with an approved carburetor cleaner,

blow dry with compressed air and reassemble.

Shelf life on gasoline is 30 days. Proper procedures
need to be taken for carburetors so that the fuel doesn’t
varnish over time. A fuel stabilizer must be used at all
times in order to ensure that the fuel is fresh at all times.

RESULTS:
If carburetor is varnished, clean or replace. Refer to

Flow Chart.

TEST 40 - VALVE ADJUSTMENT

ADJUSTING VALVE CLEARANCE:
The valve lash must be adjusted correctly in order to pro-

vide the proper air/fuel mixture to the combustion chamber.
Adjust valve clearance with the engine at room tem-

perature. The piston should be at top dead center
(TDC) of its compression stroke (both valves closed).

An alternative method is to turn the engine over and
position the intake valve fully open (intake valve spring
compressed) and adjust the exhaust valve clearance.
Turn the engine over and position the exhaust valve
fully open (exhaust valve spring compressed) and
adjust the intake valve clearance.

Correct valve clearance is given below.

Intake Valve 0.002-0.004 inch (0.05-0.1 mm)
Exhaust Valve 0.002-0.004 inch (0.05-0.1 mm)

-

Figure 6-51. – Adjusting Valve Clearance

1. Loosen the rocker arm jam nut. Use a 10mm allen wrench to

turn the pivot ball stud while checking the clearance between

the rocker arm and valve stem with a feeler gauge (see Figure

6-51).

2. When clearance is correct, hold the pivot ball stud with the

allen wrench and tighten the rocker arm jam nut to the specified

torque with a crow's foot. After tightening the jam nut, recheck

valve clearance to make sure it did not change.

Page 58

Section 6

CROW'S FOOT

DIAGNOSTIC TESTS

TORQUE SPECIFICATION

ROCKER ARM JAM NUT
168 inch-pounds (19 Nm)

Figure 6-52 – Tightening the Jam Nut

INSTALL ROCKER ARM COVER

1. Use a new rocker arm cover gasket. Install the rocker arm

cover and retain with four screws.

RESULTS:
Adjust valves to specification and retest. If problem

continues, refer to Flow Chart.

TEST 41 - CHECK ENGINE / CYLINDER LEAK

DOWN TEST / COMPRESSION TEST

Most engine problems may be classified as one or a
combination of the following:

• Will not start.

• Starts hard.

• Lack of power.

• Runs rough.

• Vibration.

• Overheating.

• High oil consumption.

Th e Cylin der Leak Down Tester (Generac P/N
0F77000SRV) checks the sealing (compression) abil­ity of the engine by measuring air leakage from the
combustion chamber. Compression loss can present
many different symptoms. This test is designed to
detect the section of the engine where the fault lies
before disassembling the engine.

PROCEDURE:

1. Remove a spark plug.

2. Gain access to the flywheel. Remove the valve cover.

3. Rotate the engine crankshaft until the piston reaches top dead

center (TDC). Both valves should be closed.

4. Lock the flywheel at top dead center.

5. Attach cylinder leak down tester adapter to spark plug hole.

6. Connect an air source of at least 90 psi to the leak down tester.

7. Adjust the regulated pressure on the gauge to 80 psi.

8. Read the right hand gauge on the tester for cylinder pressure. 20

percent leakage is normally acceptable. Use good judgement,

and listen for air escaping at the carburetor, the exhaust, and the

crankcase breather. This will determine where the fault lies.

9. Repeat Steps 1 through 8 on remaining cylinder.

RESULTS:

• Air escapes at the carburetor – check intake valve.

• Air escapes through the exhaust – check exhaust
valve.

• Air escapes through the breather – check piston
rings.

• Air escapes from the cylinder head – the head gas
ket should be replaced.

CHECK COMPRESSION:
Lost or reduced engine compression can result in (a)

failure of the engine to start, or (b) rough operation.
One or more of the following will usually cause loss of
compression:

• Blown or leaking cylinder head gasket.

• Improperly seated or sticking-valves.

• Worn Piston rings or cylinder. (This will also result in
high oil consumption).

PROCEDURE:

1. Remove both spark plugs.

2. Insert a compression gauge into either cylinder.

3. Crank the engine until there is no further increase in pressure.

4. Record the highest reading obtained.

5. Repeat the procedure for the remaining cylinder and record the

highest reading.

RESULTS:
Normal compression is approximately 150 psi. The dif-

ference in pressure between the two cylinders should
not exceed 25 percent. If the difference is greater than
25 percent, loss of compression in the lowest reading
cylinder is indicated.

Example 1: If the pressure reading of cylinder #1 is
165 psi and of cylinder #2, 160 psi, the difference is 5
psi. Divide "5" by the highest reading (165) to obtain
the percentage of 3.0 percent.

Example 2: No. 1 cylinder reads 160 psi; No. 2 cylinder
reads 100 psi. The difference is 60 psi. Divide "60" by
"160" to obtain "37.5" percent. Loss of compression in
No. 2 cylinder is indicated.

If compression is poor, look for one or more of the fol­lowing causes:

-

Page 59

LOW OIL SWITCH

Section 6
DIAGNOSTIC TESTS

• Loose cylinder head bolts.

• Failed cylinder head gasket.

• Burned valves or valve seats.

• Insufficient valve clearance.

• Warped cylinder head.

• Warped valve stem.

• Worn or broken piston ring(s).

• Worn or damaged cylinder bore.

• Broken connecting rod.

• Worn valve seats or valves.

• Worn valve guides.

NOTE: Refer to Engine Service manual No. 0F6923
for further engine service information.

TEST 42 - CHECK OIL PRESSURE SWITCH

AND WIRE 86

If the engine cranks and starts, then shuts down
almost immediately, the cause may be one or more of
the following:

• Low engine oil level.

• Low oil pressure.

• A defective oil pressure switch.

b. Start the engine while observing the oil pressure

reading on gauge.

c. Note the oil pressure.

(1) Normal oil pressure is approximately 35-40

psi with engine running. If normal oil pres­sure is indicated, go to Step 4 of this test.

(2) If oil pressure is below about 10 psi, shut

engine down immediately. A problem exists
in the engine lubrication system. Refer to
Service Manual, Generac P/N 0F6923 for
engine service recommendations.

Note: The oil pressure switch is rated at 10 psi for
v-twin engines.

3. Remove the oil pressure gauge and reinstall the oil pressure

switch. Do NOT connect Wire 86 or Wire 0 to the switch termi

nals.

a. Set a voltmeter to measure resistance.
b. Connect the meter test leads across the switch

terminals. With engine shut down, the meter
should read CONTINUITY.

c. Crank and start the engine. The meter should

read INFINITY.

d. Connect one test lead to Wire 0 ( disconnected from

LOP). Connect the other test lead to a clean frame
ground. CONTINUITY should be measured. If

CON­TINUITY is NOT measured repair or replace Wire 0
between the LOP and the ground terminal connection
on the engine mount.

4. If the LOP switch tests good in Step 3 and oil pressure is good

in Step 2, but the unit still shuts down with a LOP fault, check

Wire 86 for a short to ground. Set a voltmeter to measure

resistance. Disconnect the J2 Connector from the circuit board.

Remove Wire 86 from the LOP switch. Connect one test lead to

Wire 86. Connect the other test lead to a clean frame ground.

INFINITY should be measured. If CONTINUITY is measured,

repair or replace Wire 86 between the LOP switch and the J2

Connector.

-

Figure 6-53. – Low Oil Pressure Switch

PROCEDURE:

1. Check engine crankcase oil level.

a. Check engine oil level.
b. If necessar y, add the recommended oil to

the dipstick FULL mark. DO NOT OVERFILL
ABOVE THE FULL MARK.

2. Do the following:

a. Disconnect Wire 86 and Wire 0 from the oil

pressure switch terminals. Remove the switch
and install an oil pressure gauge in its place.

Page 60

RESULTS:

1. If switch tests good, refer to Flow Chart.

2. Replace switch if it fails the test.

TEST 43 - CHECK START STOP RELAY (SSR)

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Disconnect Wire 15 and Wire 229 from the Start Stop Relay

(SSR). See Figure 6-54.

3. Connect one meter test lead to the terminal that Wire 15 was

removed from. Connect the other meter test lead to the terminal

that Wire 229 was removed from. Resistance measured should

be approximately 100 ohms.

Section 6

100 ohm

SSR

15B

1413

9 10 12

5

1 264

8

229

0

18

14

15

15

15

85

87a

30

86

SCR

87

16

15

17

13

75 ohms

DIAGNOSTIC TESTS

RESULTS:

1. If the SSR measures continuity or zero resistance it is shorted

to ground and should be replaced.

2. If the SSR resistance is correct refer to flow chart.

Figure 6-54. – Testing Start Stop Relay (SSR)

TEST 44 - TEST STARTER CONTACTOR

RELAY (SCR)

RESULTS:

1. If the SCR measures continuity or zero resistance it is shorted

to ground and should be replaced.

2. If the SCR resistance is correct refer to flow chart.

TEST 45 - CHECK WIRE 15 CIRCUIT

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Remove the Fuse (F1).

3. Disconnect all Wire 15’s from the Start Stop Relay (SSR), dis

connect Wire 15 from the Starter Contactor (SC), Disconnect

Wire 15 from the Start-Run-Stop Switch (SW1), and disconnect

Wire 15 from the Battery Charge Rectifier 2 (BCR2).

4. Remove Wire 15 from the fuse holder (F1). Connect one meter

test lead to wire 15 just removed. Connect the other meter test

lead to frame ground. INFINITY should be measured.

RESULTS:
If INFINITY was not measured a short on Wire 15 to

ground exists. Inspect each wire 15 for a shorted con­dition. Repair or replace as needed.

-

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Disconnect Wire 15 and Wire 17 from the Starter Contactor

Relay (SCR).

3. Connect one meter test lead to the terminal that Wire 15 was

removed from. Connect the other meter test lead to the ter

minal that Wire 17 was removed from. Resistance measured

should be approximately 75 ohms.

Figure 6-55. – Testing Starter Contactor Relay (SCR)

TEST 46 - CHECK WIRE 14 CIRCUIT

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Disconnect Wire 14 from the Start Stop relay (SSR).

-

3. Connect one meter test lead to Wire 14 previously removed.

Co nnect the other meter test lead to f ra me g ro un d.

Approximately 38 ohms should be read.

RESULTS:
Refer back to flow chart.

TEST 47 - CHECK FUEL SHUTOFF SOLENOID

(FSS)

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Disconnect the plug from the Fuel Shutoff Solenoid (FSS).

3. Connect one meter test lead to one pin on the FSS. Connect

the other meter test lead to the remaining pin in the FSS.

Approximately 38 ohms should be measured.

4. Connect one meter test lead to one pin on the FSS. Connect

the other meter test lead to frame ground. INFINITY should be

measured.

Page 61

20 kohm

SSR

15B

1413

9 10 12

5

1 2

6

4

8

229

0

18

14

15

15

15

167

(START)

0

15

15

17

4

5

6

1

2

3

RUN

STOP

0

OL

Section 6
DIAGNOSTIC TESTS

RESULTS:

1. If continuity or zero was measured in Step 3 or Step 4 replace

the FSS.

2. (Units without Hourmeter) If correct resistance was measured

refer to flow chart, repair or replace Wire 14 between the FSS

and Resistor (R1).

3. (Units with Hourmeter) Refer back to flow chart.

TEST 48 - CHECK HOURMETER

PROCEDURE:

1. Disconnect Wire 14 from the hourmeter. Install new 10 Amp

fuse. Set Start Run Stop Switch (SW1) to start.

2. Check to see if fuse blew open.

RESULTS:

1. If fuse did not blow open replace the hour meter.

2. If fuse still blew repair or replace Wire 14 between the Resistor

(R1) and the Hour Meter (HM) or between the HM and the Fuel

Shutoff Solenoid (FSS).

RESULTS:

1. If continuity was measured in Step 2 but not in Step 3, replace

the printed circuit board.

2. If continuity was measured in Step 3, Wire 15B is shorted

to ground, repair or replace Wire 15B between the SSR and

printed circuit board.

TEST 50 - CHECK WIRE 167

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Disconnect Wire 167 from the Start-Run-Stop Switch (SW1).

Connect one meter test lead to Wire 167 previously removed.

Connect the other meter test lead to frame ground. See Figure

6-57. INFINITY should be measured.

3. If continuity or zero resistance was measured remove the J2

connector from the printed circuit board and repeat Step 2.

TEST 49 - CHECK WIRE 15B

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Disconnect Wire 15B from the Start Stop Relay (SSR) (see

Figure 6-56) . Connect one meter test lead to Wire 15B previ

ously removed. Connect the other meter test lead to frame

ground. Approximately 20K ohms should be measured.

3. If continuity or zero resistance was measured remove the J2

connector from the printed circuit board and repeat Step 2.

-

Figure 6-57. Check Wire 167

RESULTS:

1. If continuity was measured in Step 2 but not in Step 3, replace

the printed circuit board.

2. If continuity was measured in Step 3 wire 167 is shorted to

ground, repair or replace Wire 167 between the SW1 and

printed circuit board.

TEST 51 - CHECK WIRES 11S & 44S

Page 62

Figure 6-56. – Check Wire 15B

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Disconnect the J2 connector from the printed circuit board.

J2 HARNESS CONNECTOR

00.00

J2-1 J2-12

MAKE SURE THE TEST
PROBE CONNECTOR IS
MAKING CONTACT
WITH THE CONNECTOR.
DOUBLE CHECK TO
MAKE SURE THAT THE
TIP IS SHARP.

TB2

44S

STEP 2

STEP 3

STEP 2

STEP 3

11S

OL 00.00

OFF

SW2

ON

Section 6

DIAGNOSTIC TESTS

Connect one meter test lead to pin location J2-10 Wire 44S

of the connector just removed. Be careful not to damage the

pin connectors with the test leads. Connect the other meter

test lead to Wire 44S at Terminal Block 2 (TB2). CONTINUITY

should be measured.

3. Connect one meter test lead to pin location J2-12 Wire 11S. Be

careful not to damage the pin connectors with the test leads.

Connect the other meter test lead to Wire 11S at Terminal

Block 2 (TB2). CONTINUITY should be measured.

3. Connect meter test leads across both terminals of SW2. See

Figure 6-59.

4. In the OFF position the meter should read INFINITY or Open.

In the ON position the meter should read CONTINUITY or

Closed.

RESULTS:

1. If the switch fails Step 4 replace it.

2. If the switch is good refer back to the flow chart.

Figure 6-58. – Check Wires 11S & 44S

RESULTS:

1. If CONTINUITY was not measured, repair or replace the wire

harness.

2. If CONTINUITY was measured, refer back to the flow chart.

TEST 52 - CHECK IDLE CONTROL SWITCH

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Disconnect Wire 0 and Wire 83 from the Idle Control Switch

(SW2).

(SW2)

Figure 6-59. – Check Idle Control Switch (SW2)

TEST 53 - CHECK IDLE CONTROL WIRING

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Disconnect Wire 0 from the Idle Control Switch (SW2).

3. Connect one meter test lead to Wire 0. Connect the other meter

test lead to frame ground. CONTINUITY should be measured.

If continuity is not measured repair or replace Wire 0 between

SW2 and the ground terminal.

4. Disconnect Wire 83 from SW2. Disconnect the J2 connector

from the printed circuit board.

5. Connect one meter test lead to Wire 83 previously removed

from SW2. Connect the other meter test lead to pin location

J2-2 on the J2 connector. See Figure 6-60. Be careful not to

damage the pin connectors with the test leads. CONTINUITY

should be measured. If CONTINUITY is not measured repair or

replace Wire 83 between the J2 connector and Terminal Block

or between the Terminal Block and SW2.

Page 63

J2 HARNESS CONNECTOR

SW2

00.00

J2-1 J2-12

MAKE SURE THE TEST
PROBE CONNECTOR IS
MAKING CONTACT
WITH THE CONNECTOR.
DOUBLE CHECK TO
MAKE SURE THAT THE
TIP IS SHARP.

0

83

TERMINAL

BLOCK

(TB1)

100 ohm

86 15B

167

BLK

0 229

83

BLK

TR2

TR1

TB1

J2 HARNESS CONNECTOR

00.00

86 15B

167

BLK

0 229

83

BLK

TR2

TR1

J2-1 J2-12

MAKE SURE THE TEST
PROBE CONNECTOR IS
MAKING CONTACT
WITH THE CONNECTOR.
DOUBLE CHECK TO
MAKE SURE THAT THE
TIP IS SHARP.

Section 6
DIAGNOSTIC TESTS

7. Apply a light load to the generator, such as a electric drill.

8. When the drill is activated measure the voltage output. The AC

voltage should measure around 1-2 VAC.

RESULTS:

Refer back to flow chart.

Figure 6-61. Check Idle Transformer Wiring

Figure 6-60. – Check Idle Control Wiring

RESULTS:
Repair or replace wiring as needed. Refer back to the

flow chart.

TEST 54 - CHECK IDLE CONTROL

TRANSFORMERS (ICT)

PROCEDURE:

1. Set a voltmeter to measure resistance.

2. Remove the two Idle Control Transformer (ICT) Wires from

Terminal Block 1 (TB1). See Figure 6-61.

3. Connect one meter test lead to one wire and connect the other

meter test lead to the other wire. Approximately 100 ohms

should be measured. If resistance is not measured repair or

replace the Idle Control Transformers. If resistance was mea

sured proceed with Step 4.

4. Set a voltmeter to measure AC Voltage.

5. Connect one meter test lead to one wire and connect the other

meter test lead to the other wire.

6. Turn the Idle Control Switch (SW2) to OFF. The generator

should be running at about 60 HZ.

Page 64

TEST 55 - CHECK TR1 & TR2 WIRING

-

Figure 6-62. – Check TR2 Wiring

PROCEDURE:

TB1

J2 HARNESS CONNECTOR

00.00

86 15B

167

BLK

0 229

83

BLK

TR2

TR1

J2-1 J2-12

MAKE SURE THE TEST
PROBE CONNECTOR IS
MAKING CONTACT
WITH THE CONNECTOR.
DOUBLE CHECK TO
MAKE SURE THAT THE
TIP IS SHARP.

1. Set a voltmeter to measure resistance.

2. Disconnect the J2 connector from the printed circuit board.

3. Connect one meter test lead to Wire TR2 at Terminal Block 1

(TB1). See Figure 6-62. Connect the other meter test lead to

pin location J2-6 on the J2 Connector previously removed. Be

careful not to damage the pin connectors with the test leads.

Continuity should be measured.

4. Connect one meter test lead to Wire TR1 at Terminal Block 1

(TB1). See Figure 6-63. Connect the other meter test lead to

pin location J2-3 on the J2 Connector previously removed. Be

careful not to damage the pin connectors with the test leads.

Continuity should be measured.

RESULTS:

1. Repair or replace defective wiring.

2. If wiring tests good replace printed circuit board.

Section 6

DIAGNOSTIC TESTS

TEST 56 - CHOKE TEST

PROCEDURE:
If the generator is surging it may have a carburetion

problem. A lean condition can cause erratic RPM.
Slowly pull the choke out to see if surging stops. If it
does stop, carburetion should be checked.

Figure 6-63. – Check TR1 Wiring

Page 65

Section 7
DISASSEMBLY AND EXPLODED VIEWS

MAJOR DISASSEMBLY

STATOR, ROTOR, AND ENGINE REMOVAL.
Reference Figures A and B on Pages 68-71 for com-

ponent location.

1. Disconnect and remove the battery (Figure B, Item #15) from

the generator.

2. Remove Fuel Tank (Figure B, Item #4). Use proper safety pre-

cautions when handling gasoline.

Figure 7-3. – Control Panel Removed

Figure 7-1. – Fuel Tank Removed

3. Remove Control Panel. (Figure B) The front control panel

should be removed and Wires 11 & 44 will need to be discon-

nected from the 50 Amp circuit breaker and Wire 22 from the

50 Amp receptacle. Disconnect the stepper motor harness from

the printed circuit board. Disconnect the C1 and C2 connectors

below the control panel. Remove the control panel.

Figure 7-2. – Stepper Motor Harness

Figure 7-4. – Remove Air Deflector

4. Remove air deflector (Figure B, Item #45) from cross member.

5. Remove the Muffler. Remove the four screws holding the alter-

nator air cover on the rear of the alternator, (Figure A, Item #8).

Remove the muffler heat shield labeled HOT, Figure A, Item

#34. Remove the rear muffler box end panel, (Figure A, Item

#38). Remove the nut and washers from the top of the rear rub-

ber mounts attached to the rear bearing carrier, (Figure A, Item

32). Remove the back muffler box back panel, (Figure A, Item

37). Remove the M8 bolt from the rear bearing carrier, (Figure

A, Item #15). Remove the exhaust clamp, (Figure A, Item 35).

Remove the muffler, (Figure A, Item #6).

Page 66

Figure 7-5. – Remove Muffler

6. Remove Stator. Disconnect Wire 4 and Wire 0 from the brush

2 x 4 UNDER
BEARING
CARRIER

assembly, Figure A, Item 21. Remove the brush assembly.

Remove the four stator hold down bolts, Figure A, Item 12. Lift

the rear end of the alternator up to clear the muffler frame from

the rubber alternator mount, place a 2x4 under the front bear-

ing carrier for support. Using a rubber mallet carefully remove

the rear bearing carrier, Figure A, Item 4. Rotate the rotor so

that the steel laminations face the top and bottom. Remove the

stator can.

Section 7

DISASSEMBLY AND EXPLODED VIEWS

Figure 7-8. – Remove Stator

Figure 7-6. – Support Alternator

7. Remove Rotor. Remove rotor bolt, Figure A, Item 11. Cut 2.5

inches from the hex head end of the rotor bolt. Slot the end

of the bolt to suit a flat blade screwdriver. Slide the rotor bolt

back through the rotor and use a screwdriver to screw it into

the crankshaft. Use a 3” M12 x 1.75 bolt to screw into the rotor.

Apply torque to the 3” bolt until the taper breaks. If necessary,

when torque is applied to the 3” bolt, use a rubber mallet on the

end of the rotor shaft to break the taper.

Figure 7-7. – Remove Bearing Carrier

Figure 7-9. – Remove Rotor

Figure 7-10. – Engine Ready for Removal

8. Remove Engine. Remove the four nuts from rubber engine

mounts (Figure A, Item #29). Remove engine.

Reverse procedure for assembly.

Page 67

Section 7

10

33

39

24

14

23

46

31

13

31

39

17

28

42

43

44

19

32

10

17

16

9

3

5

30

20

1

7

25

40

19

32

22

24

26

31

36

28

32

31

28

27

45

29

18

28

10

40

41

30

11

12

21

4

34

32

15

37

6

2

35

29

8

38

DISASSEMBLY AND EXPLODED VIEWS

Generator – Figure A

Page 68

Section 7

DISASSEMBLY AND EXPLODED VIEWS

ITEM QTY. DESCRIPTION

1 1 ADAPTOR, ENGINE

2 1 STATOR

3 1 ASSEMBLY, ROTOR W/FAN

4 1 CARRIER, REAR BEARING

5 1 EXHAUST MANIFOLD

6 1 MUFFLER

7 1 GASKET, EXHAUST

8 1 COVER, ALTERNATOR AIR INTAKE

9 1 BEARING

10 3 5/16 SPECIAL LOCK WASHER

11 1 SCREW IHHC 3/8-24 X 15.50 G5

12 4 SCREW IHHC M8-1.25 X 400 G8.8

ITEM QTY. DESCRIPTION

24 5 WASHER LOCK 3/8

25 4 SCREW HHC 3/8-16 X 1-1/4 G5

26 4 WASHER FLAT 3/8-M10 ZINC

27 4 SCREW HHC M8-1.25 X 50 G8.8

28 21 WASHER FLAT 5/16 ZINC

29 4

30 7 SCREW HHC M6-1.0 X 12

31 18 WASHER LOCK M8-5/16

32 12 NUT HEX 5/16-18 STEEL

33 2 SCREW TAPTITE 3/8-16 X 3/4 BP

34 1 SHIELD, MUFFLER HEAT

35 1 U-BOLT & SADDLE

NUT LOCK HEX M8-1.25 NYLON
INSERT

13 1 BRACKET, ALT MOUNTING

14 4 SCREW HHTT #10-32 X 1.75

15 1 SCREW HHTT M8-1.2 X 20

16 1 ENGINE MOUNTING PLATE

17 6 RUBBER MOUNT

18 1 BATTERY CABLE, BLACK

19 1 EARTH STRAP 3/8X 3/8

20 1 CLIP-J VINYL COAT .625 ID

21 1 ASSEMBLY, BRUSH HOLDER

22 1 SCREW TAP-R #10-32 X 9/16

23 1 WASHER FLAT 3/8 ZINC

36 4 SCREW SHC M8-1.25 X 18

37 1 PANEL, MUFFLER BOX BACK

38 1 PANEL, MUFFLER BOX END

39 3 SCREW HHTT M6-1.0 X 12

40 7 WASHER FLAT M6-1/4

41 7 WASHER LOCK M6-1/4

42 1 SPARK ARRESTOR SCREEN

43 1 RETAINER, SPARK ARREST SCREEN

44 1 SCREW HHTT M4-0.7 X 8

45 1 SHIELD, RUBBER MOUNT

46 2 SCREW HHTT M5-0.8 X 16

Page 69

Section 7

22

21

26

30

28

5

6

7

8

9

14

32

42

24

26

27

31

29/51

29

5

19

18

17

20

16

10

1

37

3

11

12

13

33

35

7

7

6

36

34

23

39

38

41

40

39

17

2

44

43

46

25

17

6

7

47

48

49

50

52

7
6
36

Detail of Battery Tray

POWER
WIRE TO
ENGINE

4

45

CONTROL PANEL

15

DISASSEMBLY AND EXPLODED VIEWS

Frame, Handle & Wheels – Figure B

Page 70

Section 7

DISASSEMBLY AND EXPLODED VIEWS

ITEM QTY. DESCRIPTION

1 4 SCREW HHC M6-1.0 X 55

2 4 RUBBER TANK MOUNT

3 1 CAP, FUEL WITH GAUGE & VENT

4 1 KIT, FUEL TANK

5 4 NUT HEX M8-1.25

6 10 WASHER LOCK M8-5/16

7 14 WASHER FLAT 5/16

8 1 BRACKET BATTERY

9 2 BOLT,BATTERY J-BOLT

10 2 SCREW HHC 1/4-20 X 3/4 G5

11 2 WASHER FLAT 1/4

12 2 WASHER LOCK M6-1/4

13 2 NUT HEX 1/4-20

ITEM QTY. DESCRIPTION

28 1

29

30 2

AXLE, 3/4”DIA X 30” (15 kW)
AXLE, 3/4”DIA X 27.25” (12.5 kW)

2

WASHER FLAT 3/4” (15 kW)

4

WASHER FLAT 3/4” (12.5 kW)

12.3” PNEUM WHEEL 3/4” AXLE (15 kW)
10” PNEUM WHEEL 3/4” AXLE (12.5 kW)

31 2 PIN COTTER 1/8 X 1-1/4

32 2 BRACKET, WHEEL SPACER

33 4 NUT FLANGE M6-1.0 NYLOK

34 1 HANDLE

35 4 SCREW HHC 5/16-18 X 2-1/2 G5

36 6

NUT LOCK HEX 5/16-18 NYLON
INSERT

37 1 FRAME

38 4 SCREW HHC M5-0.8 X 45 G8.8

14 1 BATTERY CABLE, RED

15 1 BATTERY U1

16 1 NUT WING 5/16-18 BRASS

17 4 WASHER FLAT 5/16 BRASS

18 1 NUT HEX 5/16-18 BRASS

19 1 5/16 SPECIAL L/WASH

20 1 SCREW HHC 5/16-18 X 1.5 BRASS

21 1 BRACKET FRONT FOOT

22 2 VIB MOUNT

23 4 WASHER FLAT .25ID X 1”OD

24 2 SCREW HHC M8-1.25 X 30

25 4 SCREW HHTT M6-1.0 X 12

26 6 NUT LOCK FL 3/8-16

27 6 BOLT CARR 3/8-16 X 1

39 8 WASHER FLAT M5

40 4 WASHER LOCK M5

41 4 NUT HEX M5-0.8

42 2 WASHER FLAT 1”

43 1 BUSHING TANK DEXTOR

44 1 VALVE, PLASTIC TANK

45 1 AIR DEFLECTOR

46 2 GROMMET .75 X .06 X .50

47 2 CLAMP HOSE BAND ¼

48 18” HOSE ¼ ID

49 1 BOOT BATTERY CABLE

50 1 BOOT STARTER CABLE

51 2 SPACER, AXLE (15 kW)

52 2 SCREW HHC 5/16”-18 X 1”

Page 71

Section 8

GOVERNOR

ACTUATOR

GREEN

WHITE

Y

X

OFF

ON

+

-

WHITE

Y

X

G

30A TWISTLOK

120/240V

120V/20A

HOT HOT

3

1

WHITEWHITE

5

LINE

4

LOAD

2

C.B.

30A

C.B.

30A

C.B.

20A

C.B.

20A

C.B.

30A

30A
C.B.

CONTROL

ON/OFF
IDLE

0

LOP

FSS

SP2

IM2

D

IM1

SP1

D

IC

SSR

ENGINE WIRING

15

15

15

0

0

0

0

0

0

0

18

15

13

13

167

167

15B

11

44

22

22

22

11

11

11

11

11

11

44

44

44

44

44

44

44

0

229

11A

11A

44A

44A

44B

11B

11C

11D

44D

22

22

22

0

0

0

0

0

0

0

0

0

0

0

GFCI

DUPLEX

120V/20A

HOT

3

1

HOT

WHITE

4

5

WHITE

2

G

WHITE

G

WHITE

120V/30A

TWISTLOK

120V/30A

TWISTLOK

F1

0

0

0

0

15

15

0

0

0

0

13

15

14

14

14

14

17

15B

0

0

50A

C.B.

55

55A

11

0

11

44

86

86

86

167

83

BLACK

BATTERY

12V

RED

SM

SC

86

13

16

16

15

15

14 14

0

0

SWITCH

SCR

18

1

2

4

5

6

7

8

9

10

11

3

12

PIN #

167

0

0

44C

0

22

22

22

222222

GND

120/240V

50A OUTLET

(START)

0

15

17

RUN

STOP

22

22

22

22

0

22

22

0

0

0

0

0

0

14

1413

9 10 12

5

1 264

8

30

85

87a

86

87

ELECTRICAL DATA

Wiring Diagram 12.5 & 15 kW (Units Without Hourmeter) – Drawing No. 0E0228

Page 72

GREEN

WHITE

Y

X

OFF

ON

J2

J1

2

22

77A

66A

11

BA

44S

11S

6

44

REGULATOR

VOLTAGE

TRANSFORMERS

IDLE CONTROL

CONTROL

ON/OFF
IDLE

66

77

10A AUTO

RESET BKR

12Vdc OUTLET

77

66

6

2

77A

66A

77

66A

13A

15

15

0

0

0

0

167

15B

11

11

11

44

44

22

22

0

0

15A

BLK

229

229

44A

44A

0

0

0

0

0

4

R1

D2

1414

14

14

14

14

14

15B

BLK

ELECTRONIC GOVERNOR /

ENGINE SHUTDOWN P.C.B.

CB1

50A
C.B.

55

55

55A

86

167

83

83

86

SWITCH

TB1

TB2

RECTIFIER

BATTERY

CHARGE

BATTERY
CHARGE
RECTIFIER

4

4

4

RED

1

2

3

4

6

7

8

9

10

5

11

12

PIN #

LEGEND
BA - BRUSH ASSEMBLY
CB1 - 5AMP AUTO RESET BREAKER
D - ENGINE SHUTDOWN DIODE
D2 - 600V 12A DIODE
F1 - 10A FUSE
FSS - FUEL SHUT OFF SOLENOID
GND - GROUND BAR
IM1 - IGNITION MODULE, CYL. 1
IM2 - IGNITION MODULE, CYL. 2
LOP - LOW OIL PRESSURE
R1 - 25 OHM, 25W RESISTOR
SC - STARTER CONTACTOR

SM - STARTER MOTOR
SP1 - SPARK PLUG, CYL. 1
SP2 - SPARK PLUG, CYL. 2
SSR - START / STOP RELAY
TB1, TB2 - TERMINAL BLOCK

SCR - STARTER CONTACTOR RELAY

120/240V

50A OUTLET

66

77A

14

CLOSEST TO BEARING

0

4

STATOR

PIN 6

PIN 5

PIN 4

PIN 3

PIN 2

PIN 1

44S

162

11S

0

4

6

162

55

55A

11S

44S

55A

55

77

66

10 9 8 7 6 5 4 3 2 11112

Section 8

ELECTRICAL DATA

Page 73

VOLTAGE

ELECTRONIC

REGULATOR

11S

162

0

6

44S

4

6

5

4

3

2

1

BCR2

77A

15

66A

564

1012

SSR

9

PRINTED CIRCUIT

BOARD

CONTROL

12 1011 9 278 6 45 3J21

J1

15B

83

TR1

0

167

TR2

86

229

44S

11S

ACTUATOR

GOVERNOR

0

30A

C.B.

FIELD

BATTERY CHARGE WINDING

55A

10A BATTERY CHARGE WINDING

77

55

11S

112244

44S

66

77A 66A

62 4 0

C1-12C1-11C1-7C1-6C1-1

C1-2

C1-4

C1-9

C1-8

C1-10

C1-5

C1-3

77

66

BCR1

13A

CB2

83

167

229

15B

0

86

SW2

CB1

15A 0

F1

SCR

22914

15B

18

01515 15

0

0

14

14

14

14

86

13

15

15

1515

15

15

15

15

14

18 18

167167

8686

4

4

162

11S

44S

11

11

0

22

4444

77A

77

66A

66

77

0

2

2

2

6

6

6

11S 4 044S

RED

BLK

BLK

83 0

0

00

0

229

15B

15

15

15

0

17

17

4

POWER WINDING

DPE WINDING

I.C.T.

I.C.T.

I.C.

R1D1

TB1

TB2

12Vdc

BA

13

14

13

Section 8
ELECTRICAL DATA

Electrical Schematic 12.5 & 15 kW (Units Without Hourmeter) – Drawing No. 0E0229-A

Page 74

Section 8

RESET

RESET

TEST

TEST

18

IM2

SP2

IM1

SP1

0 0 44C2211C22

C.B.

0000

222222

44D11D44B

11B

11B

0

11A44A

22

20A

C.B.

20A30A

C.B.

30A

C.B.

30A

C.B.

50A

C.B.

30A

C.B.

0

167

SW1

C1-12C1-11C1-7C1-6C1-1

FSS

LOP

0

15

17

0

17

15

0

0

86

14

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

15

C2-12

0

0

16

SC

BATTERY

BLACK

RED

SC

SM

12V

C2-6

C2-11

C2-9

13

13

SCR

0

0

167

15

15

86

0

14

17

18

13

13

16

14

14

14

86

13

15

15

22

11

0

44

11

0

22

44

11

0

22

44

17

17

SCR - STARTER CONTACTOR RELAY

SW1 - START-RUN-STOP RELAY

SSR - START / STOP RELAY

SP2 - SPARK PLUG, CYL. 2

SP1 - SPARK PLUG, CYL. 1

SM - STARTER MOTOR

SC - STARTER CONTACTOR

R1 - 25 OHM, 25W RESISTOR

IM2 - IGNITION MODULE, CYL. 2

FSS - FUEL SHUT OFF SOLENOID

CB1 - 10AMP AUTO RESET BREAKER

LOP - LOW OIL PRESSURE

IM1 - IGNITION MODULE, CYL. 1

GND - GROUND BAR

F1 - 10A FUSE

D2, D3 - ENGINE SHUTDOWN DIODE

BA - BRUSH ASSEMBLY

LEGEND

120/240V

50A

TWISTLOK TWISTLOK

120V/30A

TWISTLOK

120V/30A

DUPLEX

120V 120V

GFCI

30A

120/240V

D2

D3

CB2 - 5AMP AUTO RESET BREAKER
D1 - 600V 12A DIODE

BCR2 - BATTERY CHARGE RECTIFIER

BCR1 - BATTERY CHARGE RECTIFIER, 10A

I.C.T. - IDLE CONTROL TRANSFORMER

SW2 - IDLE CONTROL SWITCH
TB1, TB2 - TERMINAL BLOCK

13

ELECTRICAL DATA

Page 75

Section 8

GOVERNOR

ACTUATOR

GREEN

WHITE

Y

X

OFF

ON

+

-

WHITE

Y

X

G

30A TWISTLOK

120/240V

120V/20A

HOT HOT

3

1

WHITEWHITE

5

LINE

4

LOAD

2

C.B.

30A

C.B.

30A

C.B.

20A

C.B.

20A

C.B.

30A

30A

C.B.

CONTROL

ON/OFF
IDLE

0

LOP

FSS

SP2

IM2

D

IM1

SP1

D

IC

SSR

HOURMETER

ENGINE WIRING

0

15

15

15

0

0

0

0

0

0

0

0

18

15

13

13

167

167

15B

11

44

22

22

22

11

11

11

11

11

11

44

44

44

44

44

44

44

0

229

11A

11A

44A

44A

44B

11B

11C

11D

44D

22

22

22

0

0

0

0

0

0

0

0

0

0

0

GFCI

DUPLEX

120V/20A

HOT

3

1

HOT

WHITE

4

5

WHITE

2

G

WHITE

G

WHITE

120V/30A

TWISTLOK

120V/30A

TWISTLOK

F1

0

0

0

0

15

15

0

0

0

0

13

15

14

14

14

14

14

17

15B

0

0

50A

C.B.

55

55A

11

0

11

44

86

86

86

167

83

BLACK

BATTERY

12V

RED

SM

SC

86

13

16

16

15

15

14 14

0

0

SWITCH

SCR

18

1

2

4

5

6

7

8

9

10

11

3

12

PIN #

167

0

0

44C

0

22

22

22

222222

GND

120/240V

50A OUTLET

(START)

0

15

17

RUN

STOP

22

22

22

22

0

22

22

0

0

0

0

0

0

1413

9 10 12

5

1 264

8

30

85

87a

86

87

ELECTRICAL DATA

Wiring Diagram 12.5 & 15 kW (Units With Hourmeter) – Drawing No. 0D4609-D

Page 76

GREEN

WHITE

Y

X

OFF

ON

J2

J1

2

22

77A

66A

11

BA

44S

11S

6

44

REGULATOR

VOLTAGE

TRANSFORMERS

IDLE CONTROL

CONTROL

ON/OFF
IDLE

66

77

HOURMETER

10A AUTO

RESET BKR

12Vdc OUTLET

77

66

6

2

77A

66A

77

66A

13A

15

15

0

0

0

0

0

167

15B

11

11

11

44

44

22

22

0

0

15A

BLK

229

229

44A

44A

0

0

0

0

0

4

R1

D2

1414

14

14

14

14

14

14

15B

BLK

ELECTRONIC GOVERNOR /

ENGINE SHUTDOWN P.C.B.

CB1

50A
C.B.

55

55

55A

86

167

83

83

86

SWITCH

TB1

TB2

RECTIFIER

BATTERY
CHARGE

BATTERY
CHARGE
RECTIFIER

4

4

4

RED

1

2

3

4

6

7

8

9

10

5

11

12

PIN #

LEGEND
BA - BRUSH ASSEMBLY
CB1 - 5AMP AUTO RESET BREAKER
D - ENGINE SHUTDOWN DIODE
D2 - 600V 12A DIODE
F1 - 10A FUSE
FSS - FUEL SHUT OFF SOLENOID
GND - GROUND BAR
IM1 - IGNITION MODULE, CYL. 1
IM2 - IGNITION MODULE, CYL. 2
LOP - LOW OIL PRESSURE
R1 - 25 OHM, 25W RESISTOR
SC - STARTER CONTACTOR

SM - STARTER MOTOR
SP1 - SPARK PLUG, CYL. 1
SP2 - SPARK PLUG, CYL. 2
SSR - START / STOP RELAY
TB1, TB2 - TERMINAL BLOCK

SCR - STARTER CONTACTOR RELAY

120/240V

50A OUTLET

66

77A

CLOSEST TO BEARING

0

4

STATOR

PIN 6

PIN 5

PIN 4

PIN 3

PIN 2

PIN 1

44S

162

11S

0

4

6

162

55

55A

11S

44S

55A

55

77

66

10 9 8 7 6 5 4 3 2 11112

Section 8

ELECTRICAL DATA

Page 77

VOLTAGE

ELECTRONIC

REGULATOR

11S

162

0

6

44S

4

6

5

4

3

2

1

BCR2

77A

15

66A

564

1012

SSR

9

PRINTED CIRCUIT

BOARD

CONTROL

12 1011 9 278 6 45 3J21

J1

15B83TR1

0

167

TR286229

44S

11S

ACTUATOR

GOVERNOR

0

30A

C.B.

FIELD

BATTERY CHARGE WINDING

55A

10A BATTERY CHARGE WINDING

77

55

11S

112244

44S

66

77A 66A

62 4 0

C1-12C1-11C1-7C1-6C1-1

C1-2

C1-4

C1-9

C1-8

C1-10

C1-5

C1-3

77

66

BCR1

13A

CB2

83

167

229

15B

0

86

SW2

14

HM

CB1

15A 0

0

F1

SCR

22914

15B

18

01515 15

0

0

167

15

15

86

14

17

18

13

13

16

14

14

14

14

86

13

15

15

1515

15

15

15

15

14

18 18

167167

8686

4

4

162

11S

44S

22

11

11

0

22

4444

77A

77

66A

66

77

0

2

2

2

6

6

6

11S 4 044S

RED

BLK

BLK

83 0

0

00

0

229

15B

15

15

15

0

17

17

4

POWER WINDING

DPE WINDING

I.C.T.

I.C.T.

I.C.

R1D1

TB1

TB2

12Vdc

BA

13

14

Section 8
ELECTRICAL DATA

Electrical Schematic 12.5 & 15 kW (Units With Hourmeter) – Drawing No. 0D6297-A

Page 78

Section 8

RESET

RESET

TEST

TEST

18

IM2

SP2

IM1

SP1

0 0 44C2211C22

C.B.

0000

222222

44D11D44B

11B

11B

0

11A44A

22

20A

C.B.
20A30A

C.B.

30A

C.B.

30A

C.B.

50A

C.B.

30A

C.B.

0

167

SW1

C1-12C1-11C1-7C1-6C1-1

FSS

LOP

0

15

17

0

17

15

0

0

86

14

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

15

C2-12

0

0

16

SC

BATTERY

BLACK

RED

SC

SM

12V

C2-6

C2-11

C2-9

13

13

SCR

0

0

0

167

15

15

86

0

14

17

18

13

13

16

14

14

14

86

13

15

15

22

11

0

44

11

0

22

44

11

0

22

44

17

17

SCR - STARTER CONTACTOR RELAY

SW1 - START-RUN-STOP RELAY

SSR - START / STOP RELAY

SP2 - SPARK PLUG, CYL. 2

SP1 - SPARK PLUG, CYL. 1

SM - STARTER MOTOR

SC - STARTER CONTACTOR

R1 - 25 OHM, 25W RESISTOR

IM2 - IGNITION MODULE, CYL. 2

FSS - FUEL SHUT OFF SOLENOID

CB1 - 10AMP AUTO RESET BREAKER

LOP - LOW OIL PRESSURE

IM1 - IGNITION MODULE, CYL. 1

GND - GROUND BAR

F1 - 10A FUSE

D2, D3 - ENGINE SHUTDOWN DIODE

BA - BRUSH ASSEMBLY

LEGEND

120/240V

50A

TWISTLOK TWISTLOK

120V/30A

TWISTLOK

120V/30A

DUPLEX

120V 120V

GFCI

30A

120/240V

D2

D3

CB2 - 5AMP AUTO RESET BREAKER
D1 - 600V 12A DIODE

BCR2 - BATTERY CHARGE RECTIFIER

BCR1 - BATTERY CHARGE RECTIFIER, 10A

I.C.T. - IDLE CONTROL TRANSFORMER

HM - HOURMETER

SW2 - IDLE CONTROL SWITCH
TB1, TB2 - TERMINAL BLOCK

ELECTRICAL DATA

Page 79

Section 8

ACTUATOR

GOVERNOR

SC

BLACK

12V

BATTERY

SM

RED

SP2

SP1

IM2

FSS

LOP

D

D

IM1

STOP

RUN

(START)

0

IC

PIN #

12

11

10

8

9

7

6

SCR

5

4

3

0

2

1

F1

GND

SSR

ENGINE WIRING

30A

C.B.

22

C.B.

30A

0

22

22

G

0

0

TWISTLOK

120V/30A

WHITE

22

0

0

G

WHITE

TWISTLOK

120V/30A

20A

C.B.C.B.

20A

C.B.

30A

30A

C.B.

LOAD

LINE

WHITE

HOT

3

HOT

1

WHITE

0

5

4

2

HOT

3

1

HOT

DUPLEX

120V/20A

120/240V

30A TWISTLOK

WHITE

0

4

5

WHITE

2

WHITE

120V/20A

GFCI

X

Y

G

C.B.

60A

(50A/60A) OUTLET

120/240V

50A/

55A

55

14

0

0

15

15

0

229

14

167

86

0

0

15B

44

11

18

14

44A11A

44A11A

11 44

22

44

44

44

11

11

11

11

44

11

44

44B 44

11B 11

22

0

0

22

22

11B

011B

0

0

0

44

44

0

11A

00000

0 0 0 55

0

0

0

13

15

16

17

14

13

1417

15

86

167

0

15

18

0

15

15

0

0

15

15

0

44111144

11C11D44D 44C

44C11C11D44D

22

22

22

22

22

22

22

22

0

22

0

14

1413

9 10 12

5

1 264

8

18

15

0

0

14

86

15

16

0

15

13

167

0

18

15

86

17

14

13

13

16

13

17

000

-

+

OFF

ON

GREEN

WHITE

X

Y

30

85

87a

86

87

ELECTRICAL DATA

Wiring Diagram 17.5 kW – Drawing No. 0G0731

Page 80

4

0

CLOSEST TO BEARING

STATOR

66

REGULATOR

VOLTAGE

12Vdc OUTLET

RESET BKR

10A AUTO

162

6

4

0

162

11S

22S

SCR - STARTER CONTACTOR RELAY

TB1, TB2 - TERMINAL BLOCK

SSR - START / STOP RELAY

SP2 - SPARK PLUG, CYL. 2

SP1 - SPARK PLUG, CYL. 1

SM - STARTER MOTOR

SC - STARTER CONTACTOR

R1 - 25 OHM, 25W RESISTOR

IM2 - IGNITION MODULE, CYL. 2

FSS - FUEL SHUT OFF SOLENOID

CB1 - 6AMP AUTO RESET BREAKER

LOP - LOW OIL PRESSURE

IM1 - IGNITION MODULE, CYL. 1

GND - GROUND BAR

F1 - 10A FUSE

D2 - 600V 12A DIODE

D - ENGINE SHUTDOWN DIODE

BA - BRUSH ASSEMBLY

LEGEND

RECTIFIER

CHARGE

BATTERY

CHARGE

BATTERY

RECTIFIER

D2

R1

22

ENGINE SHUTDOWN P.C.B.

ELECTRONIC GOVERNOR /

CONTROL

SWITCH

IDLE

ON/OFF

22S

55

11S 55A

TB2

TB1

BLK

CB1

BLK

RED

1

2

11

44

IDLE CONTROL
TRANSFORMERS

8

PIN #

12

10

11

9

BA

77A

5

7

6

66A

4

3

2

66

55

77

6

55A

22S

11S

22

77

4077A

66A7766 6

55

2

55A

22S

11S

44

11

11

22

22

11

44 44

83
167
229

15B

0

86

86

15B

229

14

167

0

86

0

14

0

0

15

15

0

55A

55

0

14

83

167

229

15B

0

13A

15

15

15

15

55A

55

0

14

66A

77A

4

66

77A4

0 66A 6

77

0

15A

13A

0

15A0

14

0

14

14

14

162

55

55A

J1

J2

1012 11 89 67 45 23 1

Section 8

ELECTRICAL DATA

Page 81

Section 8

86

0

14

15

15

167

0

17

16

13

13

22

44

ACTUATOR

J1

44C 0

RESET

RESET

TEST

TEST

GFCI

120V

120V/30A
TWISTLOK

CB1 - 10AMP AUTO RESET BREAKER

BCR2 - BATTERY CHARGE RECTIFIER

D2, D3 - ENGINE SHUTDOWN DIODE

CB2 - 6AMP AUTO RESET BREAKER

BCR1 - BATTERY CHARGE RECTIFIER, 10A

30A

LEGEND
BA - BRUSH ASSEMBLY

F1 - 10A FUSE

D1 - 600V 12A DIODE

22

44

0

11

11C22 0 22

120V

DUPLEX

11S

11

12

J2

120V/30A

C.B.

44D

TWISTLOK

0 11D

22 22

SC - STARTER CONTACTOR

R1 - 25 OHM, 25W RESISTOR

IM2 - IGNITION MODULE, CYL. 2

FSS - FUEL SHUT OFF SOLENOID

LOP - LOW OIL PRESSURE

IM1 - IGNITION MODULE, CYL. 1

GND - GROUND BAR
I.C.T. - IDLE CONTROL TRANSFORMER

22

0

44

11

C.B.

50A/60A

120/240V

TWISTLOK

30A

0 44B

22

50A/60A

0 11A

22

120/240V

11B

14

15

C2-7

C2-2

BATTERY CHARGE WINDING

10A BATTERY CHARGE WINDING

TB1

15B

15B

86

0

0

86

83

167

229

83229

167

VOLTAGE

REGULATOR

ELECTRONIC

C1-10

77A

77

77

C1-8

55

C1-5

77A

C1-3

55A

CONTROL

PRINTED CIRCUIT

167

5

229

TR2

86

22S

8
9

10

6

7

83

TR1

0

15B

2

3

4

1

BOARD

11S

22S

11S

TB2

22S

18

GOVERNOR

C2-1

D3

D2

15

15B

4 6
18

15B

229120

5

14

14

229

10 9

15

13

SSR

15

0

BLK

BLK

83

167

229

15B

0

86

162

6

77

11S
22S

4

BLK

77

BCR1

66

015

IM2

SP2

IM1

SP1

14 167

D1

R1

14

15

4

15

17

C2-10

15

167

C2-4

0

17

C2-3

C2-8

F1

15

SCR

16

13

C2-9

C2-11

13

C2-6

0

15

83

167

SW2

0

86

162

6

CB2

0

2

BCR2

4

13A

66A

77A

CB1

15

15A

0

C2-12

0

0

86

C2-5

15

12Vdc

0

0

POWER WINDING

C1-1

66

66

C1-9

11S

66A

C1-4

66A 11S

I.C.T.

11

BLK

22S

RED

11

I.C.

I.C.T.

C1-2

44

2 6

DPE WINDING

C1-7C1-6

2 6

SCR - STARTER CONTACTOR RELAY

SW1 - START-RUN-STOP RELAY

SSR - START / STOP RELAY

SP2 - SPARK PLUG, CYL. 2

SP1 - SPARK PLUG, CYL. 1

SW2 - IDLE CONTROL SWITCH
TB1, TB2 - TERMINAL BLOCK

SM - STARTER MOTOR

0

11

44A 0

0

FSS

SW1

0

15

17

0

SC

SC

SM

BATTERY

BLACK

12V

RED

0

LOP

0

4

C1-12

4

22

0

11

44

FIELD

C1-11

4

BA

0

0

11S

22S

22S

22

22

22SBLK

11B

C.B.

20A

C.B.
30A

C.B.
30A

C.B.

30A

C.B.

20A

0

ELECTRICAL DATA

Electrical Schematic 17.5 kW – Drawing No. 0G0733

Page 82

Section 8

CIRCUIT 16

CIRCUIT 14

CIRCUIT 12

CIRCUIT 8

CIRCUIT 6

MAIN 2

CIRCUIT 2

CIRCUIT 4

CIRCUIT 10

NEUTRAL

NEUTRAL

NEUTRAL

CIRCUIT 12

CIRCUIT 14

CIRCUIT 16

CIRCUIT 8

NEUTRAL

NEUTRAL

CIRCUIT 6

NEUTRAL

CIRCUIT 10

MAIN 1

GROUND

NEUTRAL

CIRCUIT 9

NEUTRAL

NEUTRAL

NEUTRAL

NEUTRAL

CIRCUIT 13

CIRCUIT 11

CIRCUIT 3

CIRCUIT 1

CIRCUIT 7

CIRCUIT 5

CIRCUIT 15

CIRCUIT 15

CIRCUIT 11

GROUND BAR

(ORG)

(LT BLU)

(DRK BLU)

(PNK)

(YEL/WHT)

(YEL)

(BRN/WHT)

(BRN)

(WHT)

(WHT)

(WHT)

(WHT)

(WHT)

(GRN)

(ORG)

(ORG/WHT)

(BLU/YEL)

(ORG/YEL)

(GRY/YEL)

(VIO/YEL)

(VIO)

(PNK/YEL)

(RED)

(BLK)

(WHT)

(WHT)

(WHT)

(WHT)

(WHT)

(WHT)

CIRCUIT 9

CIRCUIT 13

GROUND(GRN)*

GEN2(RED)*

GEN1(BLK)*

NEUTRAL(WHT)*

*-CUSTOMER SUPPLIED

LOAD CENTER

NEUTRAL BAR

NEUTRAL BAR

UTILITY

STANDBY

ELECTRICAL DATA

Wiring Diagram, 17.5 kW Manual Transfer Switch – Drawing No. 0G1065

Page 83

Section 8
ELECTRICAL DATA

INTERCONNECTION DRAWING – 17.5 KW GENERATOR CONNECTED TO THE EXTERNAL CONNECTION BOX, MANUAL TRANSFER
SWITCH AND HOME’S MAIN ELECTRICAL DISTRIBUTION PANEL

Page 84

NOTES

Page 85

Section 9
SPECIFICATIONS & CHARTS

GENERATOR SPECIFICATIONS

MODEL GPS 12500 GPS 15000 GPS 17500

Model #

Rated Max. Power 12.5 kW 15.0 kW 17.5 kW

Surge Power 18.75 kW 22.5 kW 26.25 kW

Rated AC Voltage 120/240 120/240 120/240

Rated Max AC Load

Current @ 240V 52.0 Amps 62.5 Amps 72.9 Amps

Current @ 120V 104.0 Amps 125.0 Amps 145.8 Amps

Rated Frequency 60 Hz @ 3600 RPM

Phase Single Phase

Rated DC Voltage 12 Volts

Rated Max DC Load
Current @ 12 Volts

Rated Horsepower
@3600 RPM

Displacement 763cc 992cc 992cc

004451

004986

ENGINE SPECIFICATIONS

27 30 33

004582

004987

005209

10 Amperes

004583

005308

Spark Plug Type Champion RC14YC or Equivalent

Spark Plug Gap 0.040 inch or (1.01 mm)

Gasoline Capacity 16 U.S. gallons

Oil Type

Oil Capacity w/ Filter Change = 1.7 Qts. w/o Filter Change = 1.4 Qts.

Run Time/Fuel
Consumption-1/2 Load

ENGINE SPEEDS AND VOLTAGE SPECIFICATIONS

Listed below are normal running voltages, load voltages and frequency ranges.

LOAD %

0 238-242 59-61

50 238-242 59-61

100 238-242 59-61

Refer to Engine Service Manual No. 0F6923 for complete GTV-760/990 V-Twin OHVI engine service information.

VOLTAGE (VAC) FREQUENCY (HZ)

Summer – SAE 30 or 10W-30

Winter – Synthetic 5W-20 or 5W-30

10 Hours / 1.6 gallons per hour

Page 86

SPECIFICATIONS & CHARTS

TORQUE SPECIFICATIONS

Flywheel Nut 150 ft. lbs.
Cylinder Head Bolts 22 ft. lbs.
Valve Cover Bolts 4.8-5.5 ft. lbs.
Rocker Arm Jam Nut 14 ft. lbs.
Ignition Coil 9 ft. lbs.
Intake Manifold 14 ft. lbs.
Exhaust Manifold 14 ft. lbs.
Stator Bolt 12 ft. lbs.
Rotor Bolt 30 ft. lbs.
Spark Plug 15 ft. lbs.
Starter Bracket To Block 18 ft. lbs.

TRIM TORQUE SPECIFICATIONS

M3-.5 PHILLIPS PAN HEAD SCREW INTO ALUMINUM 50 in. lbs.
M6-1 TAPTITE SCREW INTO ALUMINUM 9 6in. lbs.
M6-1 TAPTITE SCREW INTO WELDNUT 96 in. lbs.
M8-1.25 TAPTITE SCREW INTO ALUMINUM 18 ft. lbs.

Section 9

Page 87

PO BOX 297 • WHITEWATER, WI 53190

www.guardiangenerators.com

P/N OF7713 REV. A Printed in the USA 6.06