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.
Page 3
Table of Contents
SAFETY .................. INSIDE FRONT COVER (IFC)
NOTICE TO USERS OF THIS MANUAL ..............................IFC
REPLACEMENT PARTS .....................................................IFC
TABLE OF CONTENTS ...................................... 1-2
TRIM TORQUE SPECIFICATIONS .......................................
86
87
87
Page 2
Page 5
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
Page 6
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.
Page 7
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
Page 8
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
Page 9
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
-
-
Page 10
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
=
Page 11
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
Page 12
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).
Page 13
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
Page 14
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
Page 15
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
Page 16
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
111SSense Lead Power
244SSense Lead Power
355ABattery Charge
466ABattery Charge
577ABattery Charge
62Excitation
76Excitation
85510 Amp Battery Charge
96610 Amp Battery Charge
107710 Amp Battery Charge
114
120
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.
Page 17
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
-
Page 18
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
Page 19
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
Page 20
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)
8615B
167
BLK
0229
83
BLK
TR2
TR1
44S
11S
ENGINE DC CONTROL SYSTEM
Page 18
Page 21
NOTES
Page 19
Page 22
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
12101192786453J21
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
77A66A
6240
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
15A0
C2-6
C2-11
C2-9
13
13
F1
SCR
22914
15B
18
0151515
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
1818
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
11S4044S
RED
BLK
BLK
830
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:
Page 23
Section 4
RESET
RESET
TEST
TEST
18
IM2
SP2
IM1
SP1
0044C2211C22
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
TWISTLOKTWISTLOK
120V/30A
TWISTLOK
120V/30A
DUPLEX
120V120V
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
Page 24
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
12101192786453J21
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
77A66A
6240
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
15A0
C2-6
C2-11
C2-9
13
13
F1
SCR
22914
15B
18
0151515
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
1818
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
11S4044S
RED
BLK
BLK
830
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:
Page 25
Section 4
RESET
RESET
TEST
TEST
18
IM2
SP2
IM1
SP1
0044C2211C22
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
TWISTLOKTWISTLOK
120V/30A
TWISTLOK
120V/30A
DUPLEX
120V120V
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
Page 26
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
12101192786453J21
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
77A66A
6240
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
15A0
C2-6
C2-11
C2-9
13
13
F1
SCR
22914
15B
18
0151515
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
1818
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
11S4044S
RED
BLK
BLK
830
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:
Page 27
Section 4
RESET
RESET
TEST
TEST
18
IM2
SP2
IM1
SP1
0044C2211C22
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
TWISTLOKTWISTLOK
120V/30A
TWISTLOK
120V/30A
DUPLEX
120V120V
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
Page 28
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
12101192786453J21
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
77A66A
6240
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
15A0
C2-6
C2-11
C2-9
13
13
F1
SCR
22914
15B
18
0151515
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
1818
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
11S4044S
RED
BLK
BLK
830
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:
Page 29
Section 4
RESET
RESET
TEST
TEST
18
IM2
SP2
IM1
SP1
0044C2211C22
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
TWISTLOKTWISTLOK
120V/30A
TWISTLOK
120V/30A
DUPLEX
120V120V
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
Page 30
Section 5
GO TO PROBLEM 1
(BELOW)
GO TO PROBLEM 2GO TO PROBLEM 2GO 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
Page 31
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
Page 32
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
Page 33
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
Page 34
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
Page 35
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
GOODGOOD
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
Page 36
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
Page 37
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
Page 38
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
Page 39
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
Page 40
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 = _____________
Page 41
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
ABCDEFG
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 DRAW2.3 A
ZERO CURRENT DRAW2.1 A
ZERO CURRENT DRAW1.5 A
ZERO CURRENT DRAW1.4 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
Page 42
STEPPER
MOTOR
THROTTLE
LINKAGE
FULL THROTTLECLOSED 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.
Page 43
Section 6
TERMINAL
BLOCK
(TB1)
12.00
8615B
167
BLK
0229
83
BLK
TR2
TR1
TB1
J2 HARNESS CONNECTOR
00.00
8615B
167
BLK
0229
83
BLK
TR2
TR1
J2-1J2-12
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
Page 44
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.
Page 45
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.
WindingWire
Numbers
Power 11 & 22
Power 44 & 220.1250.0880.0890.067
Sensing11S & 44S0.250.1760.1760.134
Excitation2 & 60.5760.5461.2701.010
Battery
Charge
10A
Battery
Charge
66A & 77A0.1320.1110.1110.103
66 & 770.1450.1250.1250.117
Models
004451-0
004986-0
0.1250.0880.0880.067
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
Page 46
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.
Page 47
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
Page 48
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 004986-07.01Ω
004582-0,1 004987-0 005209-07.71Ω
004582-2 004987-113.1Ω
004583-0 005308-014.2Ω
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.
Page 49
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
-
Page 50
66
13A
77
66A
15
77A
BCR1BCR2
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
Page 51
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
Page 52
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).
Page 53
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
-
Page 54
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.
Page 55
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
Page 56
WIRE 18
SHUTDOWN
LEAD
SSR
15B
1413
91012
5
12
6
4
8
229
0
18
14
15
15
15
SSR
15B
1413
91012
5
12
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.
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
Page 57
SSR
15B
1413
91012
5
12
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
J2-1J2-12
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
8615B
167
BLK
0229
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
Page 58
1.0 vdc
SSR
15B
1413
91012
5
12
648
229
0
18
14
15
15
15
TB1
J2 HARNESS CONNECTOR
00.00
8615B
167
BLK
0229
83
BLK
TR2
TR1
J2-1J2-12
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.
-
Page 59
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. 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
Page 60
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
Page 61
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
Page 62
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.
Page 63
Section 6
100 ohm
SSR
15B
1413
91012
5
1264
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
INTERCONNECTION DRAWING – 17.5 KW GENERATOR CONNECTED TO THE EXTERNAL CONNECTION BOX, MANUAL TRANSFER
SWITCH AND HOME’S MAIN ELECTRICAL DISTRIBUTION PANEL
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
Page 89
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
Page 90
PO BOX 297 • WHITEWATER, WI 53190
www.guardiangenerators.com
P/N OF7713 REV. A Printed in the USA 6.06
Loading...
+ hidden pages
You need points to download manuals.
1 point = 1 manual.
You can buy points or you can get point for every manual you upload.