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 17-18 20-27

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

29-30

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

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 ....

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

TATOR

ROT

MAGNETIC FIEL

CURRENT

VOLTAGE

ONE CYCLE

180

360

(+)

(-)

TAT

BRUSHE

120

SLIP

RIN

RRENT

TAT

240

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

Section 3

STATOR

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

77A

66A

55A

44S

11S

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).

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

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

77A

66A

55A

44S

11S

LOCATION

77A

66A

55A

44S

11S

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:

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

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

LOCATION

C1 FEMALE SIDE

C2 FEMALE SIDE

C1 MALE SIDE

C2 MALE SIDE

LOCATION

77A

66A

55A

44S

11S

LOCATION

77A

66A

55A

44S

11S

LOCATION

167

LOCATION

167

TERMINAL BLOCK

(TB1)

TERMINAL BLOCK

(TB2)

86 15B

167

BLK

0 229

BLK

TR2

TR1

44S

11S

ENGINE DC CONTROL SYSTEM

Page 18

NOTES

Page 19

Section 4

VOLTAGE

ELECTRONIC

REGULATOR

11S

162

44S

BCR2

77A

66A

564

1012

SSR

PRINTED CIRCUIT

BOARD

CONTROL

12 1011 9 278 6 45 3J21

15B83TR10167

TR286229

44S

11S

ACTUATOR

GOVERNOR

11B

50A

C.B.

30A

C.B.

FIELD

BATTERY CHARGE WINDING

55A

10A BATTERY CHARGE WINDING

11S

112244

44S

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

BCR1

13A

CB2

167

229

15B

SW2

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

C2-12

CB1

15A 0

C2-6

C2-11

C2-9

SCR

22914

15B

01515 15

167

1515

18 18

167167

8686

162

11S

44S

4444

77A

66A

11S 4 044S

RED

BLK

83 0

229

15B

120/240V

POWER WINDING

DPE WINDING

I.C.T.

I.C.

R1D1

TB1

TB2

12Vdc

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

TEST

IM2

SP2

IM1

SP1

0 0 44C2211C22

C.B.

0000

222222

44D11D44B

11B

11A44A

20A

C.B. 20A30A

C.B.

30A

C.B.

30A

C.B.

50A

C.B.

30A

C.B.

167

SW1

FSS

LOP

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

C2-12

BATTERY

BLACK

RED

12V

C2-6

C2-11

C2-9

SCR

167

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

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

= 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

44S

BCR2

77A

66A

564

1012

SSR

PRINTED CIRCUIT

BOARD

CONTROL

12 1011 9 278 6 45 3J21

15B83TR10167

TR286229

44S

11S

ACTUATOR

GOVERNOR

11B

50A

C.B.

30A

C.B.

FIELD

BATTERY CHARGE WINDING

55A

10A BATTERY CHARGE WINDING

11S

112244

44S

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

BCR1

13A

CB2

167

229

15B

SW2

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

C2-12

CB1

15A 0

C2-6

C2-11

C2-9

SCR

22914

15B

01515 15

167

1515

18 18

167167

8686

162

11S

44S

4444

77A

66A

11S 4 044S

RED

BLK

83 0

229

15B

120/240V

POWER WINDING

DPE WINDING

I.C.T.

I.C.

R1D1

TB1

TB2

12Vdc

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

TEST

IM2

SP2

IM1

SP1

0 0 44C2211C22

C.B.

0000

222222

44D11D44B

11B

11A44A

20A

C.B. 20A30A

C.B.

30A

C.B.

30A

C.B.

50A

C.B.

30A

C.B.

167

SW1

FSS

LOP

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

C2-12

BATTERY

BLACK

RED

12V

C2-6

C2-11

C2-9

SCR

167

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

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

= 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

44S

BCR2

77A

66A

564

1012

SSR

PRINTED CIRCUIT

BOARD

CONTROL

12 1011 9 278 6 45 3J21

15B83TR10167

TR286229

44S

11S

ACTUATOR

GOVERNOR

11B

50A

C.B.

30A

C.B.

FIELD

BATTERY CHARGE WINDING

55A

10A BATTERY CHARGE WINDING

11S

112244

44S

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

BCR1

13A

CB2

167

229

15B

SW2

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

C2-12

CB1

15A 0

C2-6

C2-11

C2-9

SCR

22914

15B

01515 15

167

1515

18 18

167167

8686

162

11S

44S

4444

77A

66A

11S 4 044S

RED

BLK

83 0

229

15B

120/240V

POWER WINDING

DPE WINDING

I.C.T.

I.C.

R1D1

TB1

TB2

12Vdc

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

TEST

IM2

SP2

IM1

SP1

0 0 44C2211C22

C.B.

0000

222222

44D11D44B

11B

11A44A

20A

C.B. 20A30A

C.B.

30A

C.B.

30A

C.B.

50A

C.B.

30A

C.B.

167

SW1

FSS

LOP

C2-8

C2-3

C2-4

C2-10

C2-5

C2-7

C2-1

C2-2

C2-12

BATTERY

BLACK

RED

12V

C2-6

C2-11

C2-9

SCR

167

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

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

= 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

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