Introduction To Troubleshooting .......................70
Problem 7 – In Automatic Mode,
No Transfer to Standby ................................70
Problem 8 – In Automatic Mode, Generator
Starts When Loss of Utility Occurs,
Generator Shuts Down When Utility
Returns But There Is No Retransfer To Utility
Power / or Generator Transfers to Standby
During Exercise Or In Manual Mode............71
Problem 9 – Blown F1 or F2 Fuse ...............71
Problem 10 – Units Starts And Transfer
Occurs When Utility Power Is On .................72
Normal Operating Range-20° F (-28.8° C) to 77° F (25° C)
* Maximum wattage and current are subject to and limited by such factors as fuel Btu content, ambient temperature, altitude, engine power and condition, etc.
Maximum power decreases about 3.5 percent for each 1,000 feet above sea level; and also will decrease about 1 percent for each 6 C (10 F) above 16 C (60 F)
ambient temperature.
** Load current values shown for 120 volts are maximum TOTAL values for two separate circuits. The maximum current in each circuit must not exceed the value
stated for the 240 volts.
*** Circuits to be moved must be protected by same size breaker. For example, a 15 amp circuit in the main panel must be a 15 amp circuit in the transfer switch.
This Diagnostic Repair Manual has been prepared
especially for the purpose of familiarizing service personnel with the testing, troubleshooting and repair of
air-cooled, automatic standby generators. Every effort
has been expended to ensure that information and
instructions in the manual are both accurate and current. However, changes, alterations or other improvements may be made to the product at any time without prior notification.
The manual has been divided into PARTS. Each PART
has been divided into SECTIONS. Each SECTION
consists of two or more SUBSECTIONS.
It is not our intent to provide detailed disassembly and
reassemble instructions in this manual. It is our intent
to (a) provide the service technician with an understanding of how the various assemblies and systems
work, (b) assist the technician in finding the cause of
malfunctions, and (c) effect the expeditious repair of
the equipment.
ITEM NUMBER:
Many home standby generators are manufactured
to the unique specifications of the buyer. The Model
Number identifies the specific generator set and its
unique design specifications.
SERIAL NUMBER:
Used for warranty tracking purposes.
Page 10
Figure 1. Typical Data Plates
GENERAL INFORMATION
Part 1
sEctioN 1.2
iNstallatioN Basics
introduction
Information in this section is provided so that the
service technician will have a basic knowledge of
installation requirements for home standby systems.
Problems that arise are often related to poor or unauthorized installation practices.
A typical home standby electric system is shown in
Figure 1 (next page). Installation of such a system
includes the following:
• SelectingaLocation
• Groundingthegenerator.
• Providingafuelsupply.
• Mountingtheloadcenter.
• Connectingpowersourceandloadlines.
• Connectingsystemcontrolwiring.
• Postinstallationtestsandadjustments.
SelectinG a location
Install the generator set as close as possible to the
electrical load distribution panel(s) that will be powered by the unit, ensuring that there is proper ventilation for cooling air and exhaust gases. This will reduce
wiring and conduit lengths. Wiring and conduit not
only add to the cost of the installation, but excessively
long wiring runs can result in a voltage drop.
Control system interconnections between the transfer
switch and generator consist of N1 and N2, and leads
23, 15B and 0. Control system interconnection leads
must be run in a conduit that is separate from the AC
power leads. Recommended wire gauge size depends
on the length of the wire:
max. cable lengthrecommended Wire size
35 feet (10.67m)No. 16 AWG.
60 feet (I8.29m)No. 14 AWG.
90 feet (27.43m)No. 12 AWG.
LP (propane) gas is usually supplied as a liquid in
pressure tanks. Both the air-cooled and the liquid
cooled units require a “vapor withdrawal” type of fuel
supply system when LP (propane) gas is used. The
vapor withdrawal system utilizes the gaseous fuel
vapors that form at the top of the supply tank.
The pressure at which LP gas is delivered to the
generator fuel solenoid valve may vary considerably,
depending on ambient temperatures. In cold weather,
supply pressures may drop to “zero”. In warm weather, extremely high gas pressures may be encountered.
A primary regulator is required to maintain correct gas
supply pressures.
Current recommended gaseous fuel pressure at the inlet
side of the generator fuel solenoid valve is as follows:
lPNG
Minimum water column10 inches5 inches
Maximum water column12 inches7 inches
A primary regulator is required to ensure that proper
fuel supply pressures are maintained.
DaNGEr: lP aND Na tural Gas arE BotH
HiGHlY EXPlosiVE. GasEous fuEl liNEs
*
must BE ProPErlY PurGED aND tEstED
for lEaKs BEforE tHis EQuiPmENt is
PlacED iNt o sErVicE aND PErioDicallY
tHErEaftEr. ProcEDurEs usED iN
GasEous fuEl lEaKaGE tEsts must
comPlY strictlY WitH aPPlicaBlE fuEl
Gas coDEs. Do No t usE flamE or aNY
sourcE of HEat to tEst for Gas lEaKs.
No Gas lEaKaGE is PErmittED . lP Gas is
HEa ViEr tHaN air aND tENDs to sEttlE iN
loW arEas. Na tural Gas is liGHtEr tHaN
air aND tENDs to sEttlE iN HiGH Pla cEs.
EVEN tHE sliGHtEst sParK caN iGNitE
tHEsE fuEls aND causE aN EXPlosioN.
GroundinG the Generator
The National Electric Code requires that the frame
and external electrically conductive parts of the generator be property connected to an approved earth
ground. Local electrical codes may also require proper grounding of the unit. For that purpose, a grounding lug is attached to the unit. Grounding may be
accomplished by attaching a stranded copper wire of
the proper size to the generator grounding lug and to
an earth-driven copper or brass grounding-rod (electrode). Consult with a local electrician for grounding
requirements in your area.
the Fuel Supply
Units with air-cooled engines were operated, tested
and adjusted at the factory using natural gas as a
fuel. These air-cooled engine units can be converted
to use LP (propane) gas by making a few adjustments
for best operation and power.
Use of a flexible length of hose between the generator fuel line connection and rigid fuel lines is required.
This will help prevent line breakage that might be
caused by vibration or if the generator shifts or settles.
The flexible fuel line must be approved for use with
gaseous fuels.
Flexible fuel line should be kept as straight as possible between connections. The bend radius for flexible
fuel line is nine (9) inches. Exceeding the bend radius
can cause the fittings to crack.
the tranSFer SWitch / load center
A transfer switch is required by electrical code, to prevent electrical feedback between the utility and standby power sources, and to transfer electrical loads from
one power supply to another safely.
TRANSFER SWITCHES:
Instructions and information on transfer switches may
The utility power supply lines, the standby (generator) supply lines, and electrical load lines must all be
connected to the proper terminal lugs in the transfer
switch. The following rules apply: In 1-phase systems
with a 2-pole transfer switch, connect the two utility
source hot lines to Transfer Switch Terminal Lugs N1
and N2. Connect the standby source hot lines (E1,
E2) to Transfer Switch Terminal Lugs E1 and E2.
Connect the load lines from Transfer Switch Terminal
Lugs T1 and T2 to the electrical load circuit. Connect
UTILITY, STANDBY and LOAD neutral lines to the
neutral block in the transfer switch.
natural GaS Fuel interconnectionS
SyStem control interconnectionS
Home standby generators are equipped with a terminal board identified with the following terminals: (a)
UTILITY 1, (b) UTILITY 2, (c) 23, and (d) 15B. Load
centers house an identically marked terminal board.
When these four terminals are properly interconnected, dropout of utility source voltage below a preset
value will result in automatic generator startup and
transfer of electrical loads to the “Standby” source.
On restoration of utility source voltage above a preset
value will result in retransfer back to that source and
generator shutdown.
Figure 2. Proper Fuel Installation
Page 13
Section 1.3
WIRE NUTS
N1 (BLU)
N2 (YEL)
23 (BRN)
194 (ORG)
N1 (YEL)
N2 (YEL)
23 (WHT)
15B (RED)
0 (BLK)
CONTROL WIRES FROM
ENGINE GENERATOR
CONTROL WIRES FROM
TRANSFER SWITCH
WIRE
NUTS
N1 (BLU)
N2 (YEL)
23 (BRN)
194 (ORG)
N1 (YEL)
N2 (YEL)
23 (WHT)
15B (RED)
0 (BLK)
CONTROL WIRES FROM ENGINE GENERATOR
“08” & LATER HSB AIR-COOLED GENERATORS
SINGLE & V-TWIN ENGINES
PRE “08” LOAD CENTER
TRANSFER SWITCH
EXTERNAL CUSTOMER
CONNECTION BOX
INSTALL BATTERY CHARGER GENERAC P/N 0G8023
CONTROL WIRES FROM TRANSFER SWITCH
non-PrePackaged interconnectionS
Part 1
General information
Discussion:
on the current model air-cooled generators Wire 194
was changed to 15B. Wire 15B is still utilized for positive voltage for the transfer relay and Wire 23 is still the
control ground for transferring the generator. By following the procedures below it is possible to connect new
product with Wire 15B to old or current product that
still utilize Wire 194, such as an rts switch.
ConneCt a pre-2008 load Center switCh to a
Current or Future air-Cooled generator.
ProceDure:
1. Follow all instructions located in the Installation Manual
that was supplied with the unit regarding mounting of the
switch, junction box, and generator.
note: when installing a standalone 5500 series
generator, the battery charger will be located in the
generator on the side of the control assembly.
2. Inside the Junction box between the generator and the
transfer switch there will be 5 wires coming from the
generator and 4 wires from the transfer switch.
3. Using the following diagram and UL approved wire nuts
connect the following wires together. Wire 0 will not be
utilized for this setup.
Figure 1. Wire Connections
Page 14
Figure 2. Post 2008 HSB Interconnections
GENERAL INFORMATION
WIRE NUTS
N1 (BLU)
N2 (YEL)
23 (BRN)
194 (ORG)
N1 (YEL)
N2 (YEL)
23 (WHT)
15B (RED)
0 (BLK)
CONTROL WIRES FROM
ENGINE GENERATOR
CONTROL WIRES FROM
TRANSFER SWITCH
WIRE
NUTS
N1 (BLU)
N2 (YEL)
23 (BRN)
194 (ORG)
N1 (YEL)
N2 (YEL)
23 (WHT)
15B (RED)
0 (BLK)
CONTROL WIRES FROM ENGINE GENERATOR
PRE “08” HSB AIR-COOLED GENERATORS
SINGLE & V-TWIN ENGINES
“08” & LATER LOAD CENTER
TRANSFER SWITCH
EXTERNAL CUSTOMER
CONNECTION BOX
CONTROL WIRES FROM TRANSFER SWITCH
Part 1
connect a 2008 and later load center SWitch
to a pre-2008 air-cooled Generator.
PROCEDURE:
1. Follow all instructions located in the Installation Manual
that was supplied with the unit regarding mounting of the
switch, junction box, and generator.
note: When installing a standalone pre-2008 generator, the battery charger will be located in the
generator utilizing the 12 Vdc trickle charger.
2. Inside the Junction box between the generator and the
transfer switch there will be 4 wires coming from the
generator and 5 wires from the transfer switch.
3. Using the following diagram and UL approved wire nuts
connect the following wires together. Wire 0 will not be
utilized for this setup.
note: remove the battery charger from the transfer switch; it will not be utilized in the operation of
the generator.
sEctioN 1.3
NoN-PrEPacKaGED iNtErcoNNEctioNs
Figure 3. Wire Connections
Figure 4. Pre-2008 HSB Interconnections
Page 15
DANGER
sEctioN 1.4
PrEParatioN BEforE usE
Part 1
GENERAL INFORMATION
General
The installer must ensure that the home standby generator has been properly installed. The system must
be inspected carefully following installation. All applicable codes, standards and regulations pertaining to
such installations must be strictly complied with. In
addition, regulations established by the Occupational
Safety and Health Administration (OSHA) must be
complied with.
Prior to initial startup of the unit, the installer must
ensure that the engine-generator has been properly
prepared for use. This includes the following:
With LP gas, use only the vapor withdrawal system.
This type of system uses the vapors formed above
the liquid fuel in the storage tank.
The engine has been fitted with a fuel carburetion
system that meets the specifications of the 1997
California Air Resources Board for tamper-proof dual
fuel systems. The unit will run on natural gas or LP
gas, but it has been factory set to run on natural gas.
Should the primary fuel need to be changed to LP
gas, the fuel system needs to be reconfigured. See
the Reconfiguring the Fuel System section for instructions on reconfiguration of the fuel system.
Recommended fuels should have a Btu content of
at least 1,000 Btus per cubic foot for natural gas; or
at least 2,520 Btus per cubic foot for LP gas. Ask the
fuel supplier for the Btu content of the fuel.
Required fuel pressure for natural gas is 5 inches to
7 inches water column (0.18 to 0.25 psi); and for liquid propane, 10 inches to 12 inches of water column
(0.36 to 0.43 psi).
note: all pipe sizing, construction and layout
must comply with nFpa 54 for natural gas applications and nFpa 58 for liquid propane applications.
once the generator is installed, verify that the
fuel pressure neVer drops below four (4) inches
water column for natural gas or 10 inches water
column for liquid propane.
Prior to installation of the generator, the installer
should consult local fuel suppliers or the fire marshal
to check codes and regulations for proper installation.
Local codes will mandate correct routing of gaseous
fuel line piping around gardens, shrubs and other
landscaping to prevent any damage.
Special considerations should be given when installing the unit where local conditions include flooding, tornados, hurricanes, earthquakes and unstable
ground for the flexibility and strength of piping and
their connections.
Use an approved pipe sealant or joint compound on
all threaded fitting.
Page 16
All installed gaseous fuel piping must be purged and
leak tested prior to initial start-up in accordance with
local codes, standards and regulations.
Fuel conSumption
The fuel consumption rates are listed in the
SPECIFICATIONS section at the front of this manual.
BTU FLOW REqUIREMENTS - NATURAL GAS:
BTU flow required for each unit based on 1000 BTU
the slightest spark can ignite such fuels and
cause an explosion. No leakage of fuel is permitted. Natural gas, which is lighter than air,
tends to collect in high areas. lP gas is heavier than air and tends to settle in low areas.
note: a minimum of one approved manual shutoff valve must be installed in the gaseous fuel
supply line. the valve must be easily accessible.
local codes determine the proper location.
reconFiGurinG the Fuel SyStem
8 kW, 410CC ENGINE:
To reconfigure the fuel system from NG to LP, follow
these steps (Figure 1):
note: the primary regulator for the propane supply is not included with the generator. a fuel
pressure of 10 to 12 inches of water column (0.36
to 0.43 psi) to the fuel inlet of the generator must
be supplied.
1. Turn off the main gas supply (if connected).
2. Open the roof and remove the door.
3. Remove the battery (if installed).
4. Locate the plastic T-handle fuel selector in the poly bag
supplied with the generator.
5. Locate the selector knob on the air box cover, behind
the yellow air filter door and power bulge. The unit
comes from the factory in the NG (Natural Gas) position.
Grasping the T-handle, insert the pin end into the hole
GENERAL INFORMATION
FUEL SELECTION
LEVER -
“IN” POSITION FOR
NATURAL GAS
FUEL SELECTION
LEVER -
“OUT” POSITION FOR
LIQUID PROPANE
(VAPOR) FUEL
FUEL SELECTION
LEVER -
“IN” POSITION FOR
NATURAL GAS
Part 1
in the selector knob and pull out to overcome spring
pressure and then twist clockwise 90 degrees and allow
the selector to return in once aligned with the LP (Liquid
Propane) position.
6. Save this tool with the Owner's Manual.
7. Install the battery, door and close the roof.
8. Reverse the procedure to convert back to natural gas.
Figure 1. Demand Regulator
10, 12, 14, 16, 17 AND 20 kW, V-TWIN ENGINES:
To reconfigure the fuel system from NG to LP, follow
these steps:
note: the primary regulator for the propane supply is not included with the generator. a fuel
pressure of 10 to 12 inches of water column (0.36
to 0.43 psi) to the fuel inlet of the generator muSt
Be Supplied.
sEctioN 1.4
PrEParatioN BEforE usE
Figure 3. 10 kW, GT-530 (Inlet Hose Slid Back)
1. Open the roof.
2. for 10 kW units: Loosen clamp and slide back the
4. Reverse the procedure to convert back to natural gas.
Figure 2. 10 kW, GT-530 (Inlet Hose Slid Back)
Figure 4. 12/14/16/17/20 kW, GT-990/GT-999
(Airbox Cover Removed)
Page 17
FUEL SELECTION
LEVER -
“OUT” POSITION FOR
LIQUID PROPANE
(VAPOR) FUEL
SAE 30
Synthetic 5W-30
10W-30
sEctioN 1.4
PrEParatioN BEforE usE
Figure 5. 12/14/16/17/20 kW, GT-990/GT-999
(Airbox Cover Removed)
Part 1
GENERAL INFORMATION
enGine oil recommendationS
All oil should meet minimum American Petroleum
Institute (API) Service Class SJ, SL or better. Use
no special additives. Select the oil's viscosity grade
according to the expected operating temperature.
• SAE30è Above 32° F
• 10W-30è Between 40° F and -10° F
• Synthetic5W-30è 10° F and below
Engine crankcase oil capacities for the engines covered in this manual can be found in the specifications
section at the beginning of the book.
any attempt to crank or start the engine
before it has been properly serviced with
*
the recommended oil may result in an
engine failure.
Page 18
GENERAL INFORMATION
Part 1
sEctioN 1.5
tEstiNG, clEaNiNG aND DrYiNG
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:
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 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 polarity
switch.
b. On meters that do not have a polarity 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.
Figure 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 current
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.
Page 19
1.00 A
BATTERY
+-
RELAY
sEctioN 1.5
tEstiNG, clEaNiNG aND DrYiNG
Part 1
GENERAL INFORMATION
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.
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 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. Clamp-On Ammeter
Figure 3. A Line-Splitter
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.
Page 20
Figure 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
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:
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)
Part 1
sEctioN 1.5
tEstiNG, clEaNiNG aND DrYiNG
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.
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.
Figure 5. Electrical Units
Figure 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 21
sEctioN 1.5
tEstiNG, clEaNiNG aND DrYiNG
Part 1
GENERAL INFORMATION
ViSual inSpection
When it becomes necessary to test or troubleshoot a
generator, it is a good practice to complete a thorough
visual inspection. Remove the access covers and look
closely for any obvious problems. Look for the following:
paper, leaves, snow, and other objects that might
blow against the generator and obstr uct its air
openings.
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, dirt,
oil, grease and especially moisture. In most cases,
failures of stator and rotor windings is due to a breakdown in the insulation. And, in man y 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
The MINIMUM acceptable megger reading for stators
may be calculated using the following formula:
MINIMUM INSULATION
RESISTANCE =
(in “Megohms”)
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
windings as outlined “Stator Insulation Tests”.
Also test between parallel windings. See “Test
Between Windings” on next page.
TESTING ROTOR INSULATION (12-20kW):
Apply a voltage of 500 volts across the rotor posi -
tive (+) slip ring (nearest the rotor bearing), and
a clean frame ground (i.e. the rotor shaft). DO
NOT EXCEED 500 VOLTS AND DO NOT APPLY
VOLTAGE LONGER THAN 1 SECOND. FOLLOW
THE MEGGER MANUFACTURER’S INSTRUCTIONS
CAREFULLY.
rotor miNimum iNsulatioN rEsistaNcE:
TESTING ROTOR INSULATION (8-10kW):
No test available.
cautioN: Before attempting to measure insu-
*
lation resistance, first disconnect and isolate
all leads of the winding to be tested. Electronic
components, diodes, surge protectors, relays,
voltage regulators, etc., can be destroy ed if
subjected to high megger voltages.
GENERATOR RATED VOLTS
__________________________
1.5 megohms
1000
+1
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 8) 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.
Page 22
Figure 7. One Type of Hi-Pot Tester
GENERAL INFORMATION
2
6
11P
44
33
22S (12-20 kW)
22P
11S
(12-20 kW)
Part 1
sEctioN 1.5
tEstiNG, clEaNiNG aND DrYiNG
HI-POT TESTER:
A “Hi-Pot” tester is shown in Figure 7. 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.
Stator inSulation reSiStance teSt
(12-20 kW)
GENERAL:
Units with air-cooled engine are equipped with (a)
dual stator AC power windings, and (b) excitation or
DPE 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 8 is a pictorial representation of the
various stator leads on units with air-cooled engines.
TESTING ALL STATOR WINDINGS TO GROUND:
1. Disconnect stator output leads 11 and 44 from the generator main line circuit breaker.
2. Remove stator output leads 22 and 33 from the neutral
connection and separate the two leads.
3. Disconnect Wires 11 and 22 from Voltage Regulator.
Ensure these wires are not touching any other components on the generator.
b. Plug the tester cord into a 120 volt AC wall
socket 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
cleaning and drying, the stator fails the second test,
the stator assembly should be replaced.
6. Proceed to the Voltage Regulator. Each winding will be
individually tested for a short to ground. Refer to Steps
5a-5c and perform the same test on the following wires:
Wire
Number
22SSense Lead Power
11SSense Lead Power
6Excitation
2Excitation
0Ground
4Positive to Brush Ground
TEST BETWEEN WINDINGS:
Winding
1. Disconnect Stator Output Leads 11 and 44 from the
generator main line circuit breaker.
2. Remove Stator Output Leads 22 and 33 from the neutral
connection and separate the two leads.
Figure 8. Stator Winding Leads
4. Connect the terminal ends of Wires 11, 22, 33 and 44
together. Make sure the wire ends are not touching any
part of the generator 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, 33 and 44.
Connect the black tester lead to a clean frame ground
on the stator can. With tester leads connected in this
manner, proceed as follows:
a. Turn the Hi-Pot tester switch OFF.
3. Disc onne ct Wir es 11, 22, 2, an d 6 from Volta ge
Regulator. Ensure these wires are not touching any
other components on the generator.
4. Connect the red tester probe to Wire 2. Connect the
black tester probe to Stator Lead 11. Refer to Steps 5a
through 5c of “TESTING ALL STATOR WINDINGS TO
GROUND” on previous page.
5. Repeat Step 4 between Wire 2 and Stator Lead 33.
6. Repeat Step 4 between Stator Lead 11 and Stator Lead 33.
Stator inSulation reSiStance teSt
(8-10 kW)
GENERAL:
Units with air-cooled engine are equipped with (a)
dual stator AC power windings, and (b) excitation or
DPE 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 8 is a pictorial representation of the
various stator leads on units with air-cooled engines.
Page 23
sEctioN 1.5
POSITIVE (+)
TEST LEAD
tEstiNG, clEaNiNG aND DrYiNG
Part 1
GENERAL INFORMATION
TESTING ALL STATOR WINDINGS TO GROUND:
1. Disconnect Stator Output Leads 11 and 44 from the
generator main line circuit breaker.
2. Disconnect Stator Output Leads 2 and 6 from the
capacitor located on the end of the stator assembly.
3. Remove Stator Output Leads 22 and 33 from the neutral
connection and separate the two leads.
4. Connect the terminal ends of Wires 11, 22, 33, and 44
together. Make sure the wire ends are not touching any
part of the generator 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, 33, and 44.
Connect the black tester lead to a clean frame ground
on the stator can. With tester 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
socket 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.
6. Connect the terminal ends of Wires 2 and 6 together.
Make sure the wire ends are not touching any part of
the generator frame or any terminal.
4. Plug the tester into a 120 volts AC wall socket and set
the voltage 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.
Figure 9. Testing Rotor Insulation (12-20kW)
7. Repeat Step 5.
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.
rotor inSulation reSiStance teSt
(8-10 kW)
No test available.
rotor inSulation reSiStance teSt
(12-20 kW)
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.
Page 24
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. O p e n t h e g e ne r a to r m a i n c i rc u it b r e ak e r. N O
ELECTRICAL LOADS MUST BE APPLIED TO THE
GENERATOR WHILE DRYING.
2. Disconnect all Wires 6 from the voltage regulator.
3. 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.).
4. Start the generator and let it run for 2 or 3 hours.
5. Shut the generator down and repeat the stator and rotor
insulation resistance tests.
GENERAL INFORMATION
OIL FILTER
OIL
DRAIN
HOSE
LOW OIL SWITCH
HIGH TEMP SWITCH
L
O
O
S
E
N
Part 1
sEctioN 1.6
ENGiNE-GENErator ProtEctiVE DEVicEs
General
Standby electric power generators will often run
unattended for long periods of time. Such operating
parameters as (a) battery voltage, (b) engine oil pressure, (c) engine temperature, (d) engine operating
speed, and (e) engine cranking and startup are not
monitored by an operator during automatic operation.
Because engine operation will not be monitored, the
use of engine protective safety devices is required to
prevent engine damage in the event of a problem.
Generator engines mount several engine protective devices. These devices work in conjunction with
a circuit board, to protect the engine against such
operating faults as (a) low battery, (b) low engine oil
pressure, (c) high temperature, (d) overspeed, and
(e) overcrank. On occurrence of any one or more of
those operating faults, circuit board action will effect
an engine shutdown.
loW Battery
The microprocessor will continually monitor the battery voltage and turn on the Low Battery Warning
if the battery voltage falls below 10.8 volts for one
(1) minute. No other action is taken on a low battery
condition. Low battery voltage is a non-latching alarm
which will automatically clear if the battery voltage
rises above 11.0 volts. Battery voltage is NOT monitored during the crank cycle.
loW oil preSSure ShutdoWn
oVerSpeed ShutdoWn
During engine cranking and operation, the circuit
board receives AC voltage and frequency signals
from the ignition magneto, via Wire 18. Should the
speed exceed approximately 72 Hz (4320 rpm),
circuit board action will de-energize a “run relay”
(mounted on the circuit board). The relay’s contacts
will open, to terminate engine ignition and close a
fuel shutoff solenoid. The engine will then shut down.
This feature protects the engine-generator against
damaging overspeeds.
note: the circuit board also uses rpm sensing to
terminate engine cranking.
rpm SenSor Failure
During cranking, if the board does not see a valid
RPM signal within three (3) seconds, it will shut down
and latch out on RPM sensor loss.
During running, if the RPM signal is lost for one full
second the board will shut down the engine, wait 15
seconds, then re-crank the engine.
and run normally. If the RPM signal is subsequently
lost again, the control board will tr y one more recrank attempt before latching out and flashing the
overspeed LED or RPM Sensor Failure.
See Figure 1. An oil pressure switch is mounted on
the engine oil filter adapter. This switch has normally
closed contacts that are held open by engine oil pressure during cranking and startup. Should oil pressure
drop below approximately 5 psi, the switch contacts
will close. On closure of the switch contacts, a Wire
86 circuit from the circuit board will be connected to
ground. Circuit board action will then de-energize
a “run relay” (on the circuit board). The run relay’s
normally open contacts will then open and a 12 volts
DC power supply to a Wire 14 circuit will then be
terminated. This will result in closure of a fuel shutoff
solenoid and loss of engine ignition.
hiGh temperature SWitch
This switch’s contacts (Figure 1) close if the temperature should exceed approximately 144° C (293° F),
initiating an engine shutdown. The generator will automatically restart and the fault on the generator control
panel will reset once the temperature has returned to
a safe operating level.
Figure 1. Engine Protective Switches on an
Air-Cooled Engine
Page 25
sEctioN 1.6
ENGiNE-GENErator ProtEctiVE DEVicEs
Part 1
GENERAL INFORMATION
oVercrank ShutdoWn
This feature prevents the generator from damaging
itself when it continually attempts to start and another
problem, such as no fuel supply, prevents it from starting. The unit will crank and rest for a preset time limit.
Then, it will stop cranking, and the LCD screen or the
LED on the generator control panel will light indicating
an overcrank failure. The AUTO-OFF-MANUAL switch
will need to be set to OFF and then back to AUTO to
reset the generator control board.
note: if the fault is not repaired, the overcrank
feature will continue to activate.
The system will control the cyclic cranking as follows:
16 second crank, seven (7) second rest, 16 second
crank, seven (7) second rest followed by three (3)
additional cycles of seven (7) second cranks followed
by seven (7) second rests.
CHOkE OPERATION:
1. The 990/999cc engines have an electric choke in the
air box that is automatically controlled by the electronic
control board.
2. The 530cc engines have an electric choke on the divider
panel air inlet hose that is automatically controlled by
the electronic control board.
3. The 410cc engines have a choke behind the air box that
is automatically controlled by the electronic control board.
FAILURE TO START:
This is defined as any of the following occurrences
during cranking.
1. Not reaching starter dropout within the specified crank
cycle. Starter dropout is defined as four (4) cycles at
1,500 RPM (1,800 RPM for 8 kW units).
2. Reaching starter dropout, but then not reaching 2200
RPM within 15 seconds. In this case the control board
will go into a rest cycle for seven (7) seconds, then continue the rest of the crank cycle.
During a rest cycle the start and fuel outputs are deenergized and the magneto output is shorted to ground.
CRANkING CONDITIONS:
The following notes apply during cranking cycle.
1. Starter motor will not engage within five (5) seconds of
the engine shutting down.
2. The fuel output will not be energized with the starter.
3. The starter and magneto outputs will be energized
together.
4. Once the starter is energized the control board will begin
looking for engine rotation. If it does not see an RPM
signal within three (3) seconds it will shut down and
latch out on RPM sensor loss.
5. Once the control board sees an RPM signal it will
energize the fuel solenoid, drive the throttle open and
continue the crank sequence.
6. Star ter motor will disengage when speed reaches
starter dropout.
7. If the generator does not reach 2200 RPM within 15
seconds, re-crank cycle will occur.
8. If engine stops turning between starter dropout and 2200
RPM, the board will go into a rest cycle for seven (7)
seconds then re-crank (if additional crank cycles exist).
9. Once started, the generator will wait for a hold-off
period before starting to monitor oil pressure and oil
temperature (refer to the Alarm Messages section for
hold-off times).
10. During Manual start cranking, if the Mode switch is
moved from the Manual position, the cranking stops
immediately.
11. During Auto mode cranking, if the Utility returns, the
cranking cycle does NOT abort but continues until
complete. Once the engine starts, it will run for one (1)
minute, then shut down.
Page 26
GENERAL INFORMATION
SET
EXERCISE
SYSTEM READY
LOW BATTERY
LOW OIL PRESSURE
HIGH OIL TEMPERATURE
OVERSPEED
RPM SENSOR LOSS
OVERCRANK
ENTER
ECS
8 kW UNITS10-20 kW UNITS
Part 1
sEctioN 1.7
oPEratiNG iNstructioNs
control panel
Figure 1. Generator Control Panel
AUTO-OFF-MANUAL SWITCH:
Use this switch to (a) select fully automatic operation,
(b) to crank and start the engine manually, and (c) to
shut the unit down or to prevent automatic startup.
1. AUTO position:
a. Select AUTO for fully automatic operation.
b. When AUTO is selected, circuit board will moni-
tor utility power source voltage.
c. Should utility voltage drop below a preset level
and remain at such a low level for a preset time,
circuit board action will initiate engine cranking
and startup.
d. Following engine startup, circuit board action
will initiate transfer of electrical loads to the
“Standby” source side.
e. On restoration of utility source voltage above
a preset level, circuit board action will initiate
retransfer back to the “Utility Source” side.
f. Following retransfer, circuit board will shut the
engine down and will then continue to monitor
utility source voltage.
2. OFF Position:
a. Set the switch to OFF to stop an operating engine.
b. To prevent an automatic startup from occurring,
set the switch to OFF.
3. MANUAL Position:
a. Set switch to MANUAL to crank and start unit
manually.
b. Engine will crank cyclically and start (same as
automatic startup, but without transfer). The unit
will transfer if utility voltage is not available.
DaNGEr: WHEN tHE GENErator is
iNstallED iN coNJuNctioN WitH aN
*
automatic traNsfEr sWitcH, ENGiNE
craNKiNG aND startuP caN occur at
aNY timE WitHout WarNiNG (ProViDiNG
tHE auto-off-maNual sWitcH is sEt to
auto). to PrEVENt automatic startuP
aND PossiBlE iNJurY tHat miGHt BE
causED BY sucH startuP, alWaYs sEt
tHE auto-off-maNual sWitcH to its
off PositioN BEforE WorKiNG oN or
arouND tHis EQuiPmENt.
7.5 AMP FUSE:
This fuse protects the DC control circuit (including the
circuit board) against overload. If the fuse element
has melted open due to an overload, engine cranking
or running will not be possible. Should fuse replacement become necessary, use only an identical 7.5
amp replacement fuse.
SETTING THE EXERCISE TIMER:
This generator is equipped with an exercise timer.
Once it is set, the generator will start and exercise
every seven days, on the day of the week and at the
time of day specified. During this exercise period,
the unit runs for approximately 12 minutes and then
shuts down. Transfer of loads to the generator output
does not occur during the exercise cycle unless utility
power is lost.
8kW:
A switch on the control panel (see Figure1) permits
selection of the day and time f or the system to exercise.
At the chosen time, perform the following sequence to
select the desired day and time of day the system will
exercise. Remember seasonal time changes affect the
exercise settings .
1. Verify that the AUTO-OFF-MANUAL switch is set to AUTO.
2. Press and hold the “Set Exercise” switch for several
seconds. All the red LED’s will stop flashing immediately
and the generator will start.
3. The generator will start and run for approximately 12
minutes and then shut down. The exerciser is now set to
run at this time of day each week.
Example: If the “Set Exercise” pressed on Saturday
afternoon at 2:00 p.m., the generator will start and
exercise for approximately 12 minutes every Saturday
at 2:00 p.m.
note: the exerciser will only work in the auto
mode and will not work unless this procedure
is performed. the exerciser will need to be reset
every time the 12 Volt battery is disconnected and
then reconnected, and when the fuse is removed
and/or replaced.
Page 27
sEctioN 1.7
oPEratiNG iNstructioNs
Part 1
GENERAL INFORMATION
10-20 kW – INSTALLATION ASSISTANT:
Upon first power up of the generator, the display inter-
face will begin an installation assistant. The assistant
will prompt the user to set the minimum settings to
operate. These settings are simply: Current Date/Time
and Exercise Day/Time. The maintenance intervals
will be initialized when the exercise time is entered for
the first time (Figure 3.2).
The exercise settings can be changed at any time via
the "EDIT" menu (see Appendix, "Menu System").
If the 12 Volt battery is disconnected or the fuse
removed, the Installation Assistant will operate upon
power restoration. The only difference is the display
will only prompt the customer for the current Time
and Date.
if the installer tests the generator prior to installation, press the “enter” key to avoid setting
up the exercise time. this will ensure that when
the customer powers up the unit, he will still be
prompted to enter an exercise time.
note: the e x erciser will only work in the auto mode
and will not work unless this procedure is performed.
the current date/time will need to be reset every time
the 12 Volt battery is disconnected and then reconnected, and/or when the fuse is removed.
to Select automatic operation
The following procedure applies only to those installations in which the air-cooled, automatic standby
generator is installed in conjunction with a transfer
switch. Transfer switches do not have an intelligence
circuit of their own. Automatic operation on transfer
switch and generator combinations is controlled by
circuit board action.
To select automatic operation when a transfer switch
is installed along with a home standby generator,
proceed as follows:
1. Check that the transfer switch main contacts are at
their UTILITY position, i.e., the load is connected to the
power supply. If necessary, manually actuate the switch
main contacts to their UTILITY source side. See Part 3
of this manual, as appropriate, for instructions.
2. Check that utility source voltage is available to transfer
switch terminal lugs N1 and N2 (2-pole, 1-phase transfer
switches).
3. Set the generator AUTO-OFF-MANUAL switch to its
AUTO position.
4. Actuate the generator main line circuit breaker to its “On”
or “Closed” position. With the preceding Steps 1 through
4 completed, a dropout in utility supply voltage below a
preset level will result in automatic generator cranking
and start-up. Following startup, the transfer switch will be
actuated to its “Standby” source side, i.e., loads powered
by the standby generator.
manual tranSFer to “StandBy” and
manual Startup
To transfer electrical loads to the “Standby” (generator)
source and start the generator manually, proceed as
follows:
1. On the generator panel, set the AUTO-OFF-MANUAL
switch to OFF.
2. On the generator, set the main line circuit breaker to it’s
OFF or “Open” position.
3. Turn OFF the power supply to the transfer switch, using
whatever means provided (such as a utility source line
circuit breaker).
4. Manually actuate the transfer switch main contacts to
their “Standby” position, i.e., loads connected to the
“Standby” power source side.
note: For instructions on manual operation of
transfer switches, see part 3.
5. On the generator panel, set the AUTO-OFF-MANUAL
switch to MANUAL. The engine should crank and start.
6. Let the engine warm up and stabilize for a minute or two
at no-load.
7. Set the generator main line circuit breaker to its “On”
or “Closed” position. The generator now powers the
electrical loads.
manual ShutdoWn and retranSFer
Back to “utility”
To shut the generator down and retransfer electrical
loads back to the UTILITY position, proceed as follows:
1. Set the generator main line circuit breaker to its OFF or
“Open” position.
2. Let the generator run at no-load for a few minutes, to cool.
3. Set the generator AUTO-OFF-MANUAL switch to OFF.
Wait for the engine to come to a complete stop.
4. Turn off the utility power supply to the transfer switch
using whatever means provided (such as a utility source
main line circuit breaker)
5. Manually actuate the transfer switch to its UTILITY
source side, i.e., load connected to the utility source.
6. Turn on the utility power supply to the transfer switch,
using whatever means provided.
7. Set the generator AUTO-OFF-MANUAL switch to AUTO.
Page 28
GENERAL INFORMATION
Part 1
sEctioN 1.8
automatic oPEratiNG ParamEtErs
introduction
When the generator is installed in conjunction with
a transfer switch, either manual or automatic operation is possible. Manual transfer and engine startup,
as well as manual shutdown and re-transfer are
covered in Section 1.7. Selection of fully automatic
operation is also discussed in that section. This
section will provide a step-by-step description of the
sequence of events that will occur during automatic
operation of the system.
utility Failure
Initial Conditions: Generator in Auto, ready to run,
load being supplied by utility source. When utility
fails (below 65% of nominal), a 10 second (optionally
programmable on the 17 and 20 kW only) line interrupt delay time is started. If the utility is still gone
when the timer expires, the engine will crank and
start. Once started, a five (5) second engine warmup
timer will be initiated.
When the warm-up timer expires, the control will
transfer the load to the generator. If the utility power
is restored (above 75% of nominal) at any time from
the initiation of the engine start until the generator
is ready to accept load (5 second warm-up time has
not elapsed), the controller will complete the start
cycle and run the generator through its normal cool
down cycle; however, the load will remain on the utility
source.
FAILURE TO START:
This is defined as any of the following occurrences
during cranking.
1. Not reaching starter dropout within the specified crank
cycle. Starter dropout is defined as four (4) cycles at
1,000 RPM.
2. Reaching starter dropout, but then not reaching 2200
RPM within 15 seconds. In this case the control board
will go into a rest cycle for seven (7) seconds, then
continue the rest of the crank cycle.
During a rest cycle the start and fuel outputs are
de-energized and the magneto output is shorted to
ground.
CRANkING CONDITIONS:
The following notes apply during cranking cycle.
1. Starter motor will not engage within five (5) seconds of
the engine shutting down.
2. The fuel output will not be energized with the starter.
3. The starter and magneto outputs will be energized
together.
4. Once the starter is energized the control board will begin
looking for engine rotation. If it does not see an RPM
signal within three (3) seconds it will shut down and
latch out on RPM sensor loss.
crankinG
The system will control the cyclic cranking as follows:
16 second crank, seven (7) second rest, 16 second
crank, seven (7) second rest followed by three (3)
additional cycles of seven (7) second cranks followed
by seven (7) second rests.
CHOkE OPERATION:
1. The 990/999cc engines have an electric choke in the
air box that is automatically controlled by the electronic
control board.
2. The 530cc engines have an electric choke on the divider
panel air inlet hose that is automatically controlled by
the electronic control board.
3. The 410cc engines have a choke behind the air box
that is automatically controlled by the electronic control
board.
5. Once the control board sees an RPM signal it will
energize the fuel solenoid, drive the throttle open and
continue the crank sequence.
6. Starter motor will disengage when speed reaches starter
dropout.
7. If the generator does not reach 2200 RPM within 15
seconds, re-crank cycle will occur.
8. If engine stops turning between starter dropout and
2200 RPM, the board will go into a rest cycle for seven
(7) seconds then re-crank (if additional crank cycles
exist).
9. Once started, the generator will wait for a holdoff period
before starting to monitor oil pressure and oil temperature
(refer to the Alarm Messages section for hold-off times).
10. During Manual start cranking, if the Mode switch is
moved from the Manual position, the cranking stops
immediately.
11. During Auto mode cranking, if the Utility returns, the
cranking cycle does NOT abort but continues until
complete. Once the engine starts, it will run for one (1)
minute, then shut down.
Page 29
sEctioN 1.8
automatic oPEratiNG ParamEtErs
load tranSFer
The transfer of load when the generator is running is
dependent upon the operating mode as follows:
utility fails during exercise for 10 seconds, and will
switch to Auto mode.
Part 1
GENERAL INFORMATION
utility reStored
Initial Condition: Generator supplying power to customer load. When the utility returns (above 75% of
nominal), a 15 second return to utility timer will start.
At the completion of this timer, if the utility supply is
still present and acceptable, the control will transfer
the load back to the utility and run the engine through
a one (1) minute cool down period and then shut
down. If utility fails for three (3) seconds during this
cool down period, the control will transfer load back to
the generator and continue to run while monitoring for
utility to return.
Page 30
Part 2
ac GENErators
air-cooled, automatic
standby Generators
taBlE of coNtENts
ParttitlEPaGE#
2.1.Description and components30
2.2operational analysis33
2.3troubleshooting flow charts35
2.4Diagnostic tests39
2.1 Description and Components .......................... 32
Under Load..........................................52
Test 19 – Check F or Overload Condition ...........52
Test 20 – Check Engine Condition ...................52
Test 21 – Field Flash Alternator (8-10 kW) ......52
Page 31
"C"
"B"
"C"
ROTOR
"B"
"C"
9
"D"
"B"
"C"
"D"
BEARING CARRIER
BRUSH HOLDER
ASSEMBLY
ENGINE ADAPTOR
"8KW"
"8KW - 10KW"
ENGINE ADAPTOR
"10KW"
0.8
"D"
"D"
STATOR
"12KW - 20KW"
"12KW - 20KW"
sEctioN 2.1
DEscriPtioN & comPoNENts
Part 2
AC GENERATORS
introduction
The air-cooled, automatic standby system is an easy
to install, fully enclosed and self-sufficient electric
power system. It is designed especially for homeowners, but may be used in other applications as well.
On occurrence of a utility power failure, this high
performance system will (a) crank and start automatically, and (b) automatically transfer electrical loads to
generator AC output.
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.
A 2-pole, “W/V-Type” transfer switch is offered (see
Part 3). The transfer switch does not include an “intelligence circuit” of it’s own. Instead, automatic startup,
transfer, running, retransfer and shutdown operations
are controlled by a solid state circuit board in the
generator control panel.
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), and mounted in an enclosure. Both the engine and
generator rotor are driven at approximately 3600 rpm,
to provide a 60 Hz AC output.
the ac Generator
Figure 1 shows the major components of the AC
generator.
rotor aSSemBly
12-20 kW:
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. 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.
Page 32
Figure 1. AC Generator Exploded View
AC GENERATORS
SLIP RINGS
BEARING
2
6
11P
44
33
22S (12-20 kW)
22P
11S
(12-20 kW)
CATHODE
ANODE
DIODE B
DIODE B
CATHODE
DIODE A
COIL 2
ANODE
COIL 1
DIODE A
BEARING
Part 2
Figure 2. The 2-Pole Rotor Assembly 12-20 kW
8/10kW:
Like the 12-20 kW rotor, the 8/10 kW 2-pole rotor must
be operated at 3600 rpm to supply a 60 Hertz AC frequency. However, the 8/10kW rotor uses no slip rings.
As the rotor rotates in the generator voltage is induced
from the Excitation winding using a capacitor that is in
turn excited by the rotor. A continuous loop of charging
and discharging of the capacitor is maintained that
acts as a voltage regulation system. 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.
sEctioN 2.1
DEscriPtioN & comPoNENts
Stator aSSemBly
The stator can houses and retains (a) dual AC power
windings, and (b) excitation winding. A total of six (6)
or eight (8) stator leads are brought out of the stator
can as shown in Figure 4.
The stator can is sandwiched between an engine
adapter and a rear bearing carrier. It is retained in that
position by four stator studs.
Figure 4. Stator Assembly Leads
Figure 3. The 2-Pole Rotor Assembly 8/10kW
Page 33
0
4
-
+
sEctioN 2.1
DEscriPtioN & comPoNENts
Part 2
AC GENERATORS
BruSh holder and BruSheS
(12-20 kW)
The brush holder is retained to the rear bearing carrier by means of two #10-32 x 9/16 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.
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.
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.
Figure 5. Typical Voltage Regulator
A single red lamp (LED) glows during normal operation. 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
with a frequency of 60 Hz
At the stated no-load frequency, adjust to obtain a
line-to-line AC voltage of 247-249 volts.
Figure 4. Brush Holder and Brushes (12-20 kW)
other ac Generator componentS
Some AC generator components are housed in the
generator control panel enclosure, and are not shown
in Figure 1. These are (a) a voltage regulator, and (b)
a main line circuit breaker.
VOLTAGE REGULATOR (12-20 kW):
A typical voltage regulator is shown in Figure 5.
Unregulated AC output from the stator excitation
winding is delivered to the regulator’s DPE terminals,
via Wire 2 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 11 and 22.
Page 34
MAIN LINE CIRCUIT BREAkER:
The main line circuit breaker protects the generator
against electrical overload. See “Specifications” in
front of manual for amp ratings.
AC GENERATORS
DIODE
PIN 5
PIN 1
BASE
TRANSISTOR
FIELD
BOOST
RESISTOR
FIELD
BOOST
DIODE
STARTER
CONTACTOR
TO
STARTER
+12 VDC
FIELD
BOOST
TO
ROTOR
CRANk
RELAY k1
CIRCUIT BOARD
56
4
13
STATOR
EXCITATION
WINDING
VOLTAGE
REGULATOR
FIELD BOOST FROM
CONTROL LOGIC
CIRCUIT BOARD
STATOR
POWER
WINDING
STATOR
POWER
WINDING
MAGNETIC
FIELD
MAGNETIC
FIELD
MLB = MAIN LINE CIRCUIT BREAKER
ROTOR
SENSING
TO LOAD
MLB
ENGINE DIRECT
DRIVE
12-20 kW Units
CAPACITOR
STATOR
EXCITATION
WINDING
STATOR
POWER
WINDING
STATOR
POWER
WINDING
MAGNETIC
FIELD
MAGNETIC
FIELD
MLB = MAIN LINE
CIRCUIT BREAKER
ROTOR
TO LOAD
MLB
ENGINE DIRECT
DRIVE
8/10 kW Units
Part 2
sEctioN 2.2
oPEratioNal aNalYsis
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 (12-20 kW)
FIELD BOOST CIRCUIT:
When the engine is cranking, direct current flow is
delivered from a circuit board to the generator rotor
windings, via Wire 4.
The field boost system is shown schematically in
Figure 2. Manual and automatic engine cranking
is initiated by circuit board action, when that circuit
board energizes a crank relay. Battery voltage is then
delivered to field boost Wire 4 (and to the rotor), via
a field boost resistor and diode. The crank relay, field
boost resistor and diode are all located on the circuit
board.
Notice that field boost current is available only while
the crank relay is energized, i.e., while the engine is
cranking.
Field boost voltage is reduced from that of battery
voltage by the resistor action and, when read with a
DC voltmeter, will be approximately 9 or 10 volts DC.
Figure 2. Field Boost Circuit Schematic
Figure 1. Operating Diagram of AC Generator
Page 35
sEctioN 2.2
oPEratioNal aNalYsis
Part 2
AC GENERATORS
operation (8/10 kW)
STARTUP:
When the engine is started, residual magnetism from
the rotor induces a voltage into (a) the stator AC
power windings, and (b) the stator excitation or DPE
windings. The capacitor on the DPE winding will be
charged and then will discharge causing a voltage to
be induced back into the rotor.
FIELD EXCITATION:
An AC voltage is induced into the stator excitation
(DPE) windings. The DPE winding circuit is completed
to the capacitor, via Wire 2 and Wire 6.
The capacitor will charge at a rate that is dependant
on the amount of voltage that is being induced into it.
Once the capacitor is fully charged the voltage that
it discharges is a constant voltage and will in-turn
increase the size of the magnetic field of the rotor.
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.
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.
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 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 11 and 22.
The regulator changes the AC from the excitation
winding to DC. In addition, based on the Wires 11
and 22 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.
operation (12-20 kW)
STARTUP:
When the engine is started, residual plus field boost
magnetism from the rotor induces a voltage into
(a) the stator AC power windings, and (b) the stator excitation or DPE windings. In an “on-speed”
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.
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.
Page 36
Use the “Flow Charts” in conjunction with the detailed
REPAIR
OR
REPLACE
REPAIR
OR
REPLACE
REPAIR
OR
REPLACE
THEN
RETEST
REPLACE
VOLTAGE
REGULATOR
TEST 1 - CHECK
MAIN CIRCUIT
BREAKER
TEST 4 - PERFORM
FIXED EXCITATION /
ROTOR AMP DRAW
PERFORM STATOR
INSULATION
RESISTANCE TEST
-
SECTION 1.4
PERFORM ROTOR
INSULATION
RESISTANCE TEST
-
SECTION 1.4
TEST 7 - TEST
STATOR
TEST 5 - WIRE
CONTINUITY
TEST 6 -
FIELD BOOST
TEST 11 -
CHECK
ROTOR
RESISTANCE
CHECK
VOM
FUSES
TEST 12 -
CHECK
BRUSHES &
SLIP RINGS
TEST 13 -
TEST ROTOR
ASSEMBLY
REPAIR
OR REPLACE
FUSES
RE-TEST
BAD
BAD
BAD
BAD
BAD
BAD
BAD
BAD
GOOD
GOOD
GOOD
GOOD
Problem 1 - Generator Produces Zero Voltage or Residual Voltage
(12-20 kW)
D
G
A
C
B
GOOD
GOOD
RESET TO
“ON”
OR REPLACE
IF BAD
instructions in Section 2.4. Test numbers used in
the flow charts correspond to the numbered tests in
Section 2.4.
AC GENERATORS
Part 2
sEctioN 2.3
trouBlEsHootiNG floWcHarts
General
The first step in using the flow charts is to correctly
identify the problem. Once that has been done, locate
the problem on the following pages. For best results,
perform all tests in the exact sequence shown in the
flow charts.
Page 37
STOP
TESTING
GOOD
REPLACE
BAD
REPLACE
STATOR
REPLACE
STATOR
REPLACE
ROTOR
TEST 1 - CHECK
MAIN CIRCUIT
BREAKER
TEST 8 - TEST
BRUSHLESS
STATOR
TEST 9 -
CHECK
CAPACITOR
REPLACE
CAPACITOR
TEST 10 - TEST
DPE WINDING
TEST 21 -
FIELD FLASH
ALTERNATOR
TEST 2 -
CHECK AC
OUTPUT
VOLTAGE
BAD
BAD
GOODON
GOOD
GOOD
Problem 2 - Generator Produces Zero Voltage or Residual Voltage
(8/10 kW)
RESET TO
“ON”
OR REPLACE
IF BAD
BAD
TEST 4 - PERFORM
FIXED EXCITATION /
ROTOR AMP DRAW
TEST 7 - TEST
STATOR
TEST 7 - TEST
STATOR
TEST 13 -
TEST ROTOR
ASSEMBLY
TEST 13 -
TEST ROTOR
ASSEMBLY
REPAIR
OR
REPLACE
BAD
GOOD
GOOD
GOOD
GOOD
GOOD
GOOD
GOOD
GOOD
BAD
BAD
BAD
BAD
BAD
BAD
BAD
RE-TEST
TEST 4
RE-TEST
TEST 4
REPAIR
OR
REPLACE
Problem 1 - Generator Produces Zero Voltage or Residual Voltage
(12-20 kW Continued)
F
E
H
PERFORM STATOR
INSULATION
RESISTANCE TEST -
SECTION 1.4
PERFORM STATOR
INSULATION
RESISTANCE TEST -
SECTION 1.4
PERFORM ROTOR
INSULATION
RESISTANCE TEST -
SECTION 1.4
PERFORM ROTOR
INSULATION
RESISTANCE TEST -
SECTION 1.4
sEctioN 2.3
trouBlEsHootiNG floWcHarts
Part 2
AC GENERATORS
Page 38
AC GENERATORS
STOP
TESTS
FREQUENCY O.K.,
BUT VOLTAGE LOW
TEST 14 - CHECK
AC OUTPUT
FREQUENCY
TEST 15 - ADJUST
ENGINE GOVERNOR
TEST 16 - CHECK
STEPPER MOTOR
CONTROL
TEST 2 - CHECK
AC OUTPUT
VOLTAGE
TEST 17 - ADJUST
VOLTAGE
REGULATOR
TEST 9 -
CHECK
CAPACITOR
LOW
LOW -
SINGLE CYLINDER
UNITS
LOW -
V-TWIN UNITS
FREQUENCY O.K.,
BUT VOLTAGE IS
STILL LOW
GO TO “PROBLEM 1” FLOW CHART START AT “TEST 4 - F/E”
GO TO “PROBLEM 2”
VOLTAGE AND FREQUENCY O.K.
8/10 kW UNITS
8/10 kW UNITS
NO VOLTAGE
GO TO TEST 4
GO TO “PROBLEM 2”
8/10 kW UNITS
12-20 kW UNITS
12-20 kW UNITS
12-20 kW UNITS
FREQUENCY AND
VOLTAGE O.K.
Problem 3 - Generator Produces Low Voltage at No-Load
STOP
TESTS
Problem 4 - Generator Produces High Voltage at No-Load
TEST 14 - CHECK
AC OUTPUT
FREQUENCY
TEST 15 - ADJUST
ENGINE GOVERNOR
TEST 16 - CHECK
STEPPER MOTOR
CONTROL
TEST 2 - CHECK
AC OUTPUT
VOLTAGE
HIGH
HIGH -
SINGLE CYLINDER
UNITS
HIGH -
V-TWIN UNITS
REPLACE DEFECTIVE
VOLTAGE REGULATOR
FREQUENCY AND
VOLTAGE O.K.
TEST 17 - ADJUST
VOLTAGE
REGULATOR
TEST 9 -
CHECK
CAPACITOR
8/10 kW UNITS
12-20 kW UNITS
FREQUENCY O.K.,
BUT VOLTAGE IS
STILL HIGH
FREQUENCY O.K.,
BUT VOLTAGE HIGH
VOLTAGE AND FREQUENCY O.K.
GO TO “PROBLEM 2”
8/10 kW UNITS
12-20 kW UNITS
Part 2
sEctioN 2.3
trouBlEsHootiNG floWcHarts
Page 39
sEctioN 2.3
GOOD
GOOD
REPAIR OR REPLACE
IF RECONFIGURED TO LP GAS,
VERIFY THAT PROPER
PROCEDURE WAS FOLLOWED
(REFER TO SECTION 1.3)
TEST 18 - CHECK
VOLTAGE AND
FREQUENCY
UNDER LOAD
TEST 19 - CHECK
FOR OVERLOAD
CONDITION
TEST 15 - CHECK AND
ADJUST ENGINE
GOVERNOR
GO TO “PROBLEM 18 -
ENGINE STARTS HARD
AND RUNS
ROUGH/LACKS POWER”
SECTION 4.3
TEST 20 - CHECK
ENGINE CONDITION
NOT
OVERLOADED
GOOD
ENGINE
CONDITION
GOOD
DISCONTINUE
TESTING
LOOK FOR A SHORTED
CONDITION IN A
CONNECTED LOAD OR
IN ONE OF THE LOAD
CIRCUITS
REDUCE LOADS TO UNIT’S
RATED CAPACITY
BAD
REPAIR OR REPLACE
OVERLOADED
Problem 4 - Voltage and Frequency Drop Excessively When Loads Are Applied
UNITS WITH
V-TWIN
ENGINES
UNITS WITH
SINGLE
CYLINDER
ENGINES
TEST 7 - CHECK
STATOR AC
POWER WINDINGS
BOTH
LOW
GOOD
GOOD
BAD
GOOD
REPLACE
TEST 8 - TEST
BRUSHLESS
STATOR
TEST 10 - TEST
DPE WINDING
BAD
BAD
GOOD
TEST 16 - CHECK
STEPPER MOTOR
CONTROL
8/10 kW UNITS
12-20 kW UNITS
Part 2
AC GENERATORS
trouBlEsHootiNG floWcHarts
Page 40
AC GENERATORS
OFF
WIRE 11
TERMINAL
E1 TERMINAL
E2 TERMINAL
WIRE 44
TERMINAL
Part 2
sEctioN 2.4
DiaGNostic tEsts
introduction
This section is provided to familiarize the service
technician with acceptable procedures for the testing and evaluation of various problems that could be
encountered on standby generators with air-cooled
engine. Use this section of the manual in conjunction
with Section 2.3, “Troubleshooting Flow Charts”. The
numbered tests in this section correspond with those
of Section 2.3.
Test procedures in this section do not require the use
of specialized test equipment, meters or tools. Most
tests can be performed with an inexpensive voltohm-milliammeter (VOM). An AC frequency meter is
required, where frequency readings must be taken. A
clamp-on ammeter may be used to measure AC loads
on the generator.
Testing and troubleshooting methods covered in this
section are not exhaustive. We have not attempted to
discuss, evaluate and advise the home standby service trade of all conceivable ways in which service and
trouble diagnosis might be performed. We have not
undertaken any such broad evaluation. Accordingly,
anyone who uses a test method not recommended
herein must first satisfy himself that the procedure or
method he has selected will jeopardize neither his nor
the product’s safety.
1. Set a volt-ohm-milliammeter (VOM) to its “R x 1” scale
and zero the meter.
2. With the generator shut down, disconnect all wires from
the main circuit breaker terminals, to prevent interaction.
3. With the generator shut down, connect one VOM test
probe to the Wire 11 terminal of the breaker and the
other test probe to the Wire E1 terminal.
4. Set the breaker to its “On” or “Closed” position. The VOM
should read CONTINUITY.
5. Set the breaker to its OFF or “Open” position and the
VOM should indicate INFINITY.
6. Repeat Steps 4 and 5 with the VOM test probes connected across the breaker’s Wire 44 terminal and the E2
terminal.
RESULTS:
1. If the circuit breaker tests good, go on to Test 2.
2. If the breaker tests bad, it should be replaced.
SaFety
Service personnel who work on this equipment must
be made aware of the dangers of such equipment.
Extremely high and dangerous voltages are present
that can kill or cause serious injury. Gaseous fuels are
highly explosive and can be ignited by the slightest
spark. Engine exhaust gases contain deadly carbon
monoxide gas that can cause unconsciousness or
even death. Contact with moving parts can cause serious injury. The list of hazards is seemingly endless.
When working on this equipment, use common
sense and remain alert at all times. Never work on
this equipment while you are physically or mentally
fatigued. If you don’t understand a component, device
or system, do not work on it.
teSt 1 – check main circuit Breaker
DISCUSSION:
Often the most obvious cause of a problem is over-
looked. If the generator main line circuit breaker is set
to OFF or “Open”, no electrical power will be supplied
to electrical loads. If loads are not receiving power,
perhaps the main circuit breaker is open or has failed.
PROCEDURE:
The generator main circuit breaker is located on the
control panel. If loads are not receiving power, make
sure the breaker is set to “On” or “Closed”.
If you suspect the breaker may have failed, it can be
tested as follows (see Figure 1):
Figure 1. Generator Main Circuit Breaker Test Points
teSt 2 – check ac output VoltaGe
DISCUSSION:
A volt-ohm-milliammeter (VOM) may be used to check
the generator output voltage. Output voltage may be
checked at the unit’s main circuit breaker terminals.
Refer to the unit’s DATA PLATE for rated line-to-line
and line-to-neutral voltages.
Page 41
11
22
4
4
0
6
2
sEctioN 2.4
DiaGNostic tEsts
Part 2
AC GENERATORS
DaNGEr: usE EXtrEmE cautioN
*
PROCEDURE:
DuriNG tHis tEst. tHE GENErator Will
BE ruNNiNG. HiGH aND DaNGErous
VoltaGEs Will BE PrEsENt at tHE
tEst tErmiNals. coNNEct mEtEr tEst
clamPs to tHE HiGH VoltaGE tErmiNals
WHilE tHE GENErator is sHut DoWN.
staY clEar of PoWEr tErmiNals
DuriNG tHE tEst. maKE surE mEtEr
clamPs arE sEcurElY attacHED aND
Will Not sHaKE loosE.
1. With the engine shut down, connect the AC voltmeter
test leads across the Wires 11 and 44 terminals of the
generator main circuit breaker (see Figure 1). These
connections will permit line-to-line voltages to be read.
2. Set the generator main circuit breaker to its OFF or
“Open” position. This test will be conducted with the
generator running at no-load.
3. Start the generator, let it stabilize and warm up for a
minute or two.
PROCEDURE:
1. Disconnect Wire 4 from the voltage regulator, 3rd
terminal from the top. See Figure 2.
2. Connect a jumper wire to the disconnected Wire 4 and
to the 12 volt fused battery supply Wire 15B (located at
TB1 terminal board).
3. Set VOM to AC volts.
4. Take the meter reading. On 12-20 kW units the no-load
voltage should be between 249-247 VAC. On 8-10 kW
units the no-load voltage should be between 220-235 VAC.
5. Shut the engine down and remove the meter test leads.
RESULTS:
1. If Step 4 indicated proper voltages, discontinue testing.
2. If any other readings were measured, refer back to flow
chart.
note: “residual” voltage may be defined as the
voltage that is produced by rotor residual magnetism alone. the amount of voltage induced into
the stator ac power windings by residual voltage alone will be approximately 2 to 16 volts ac,
depending on the characteristics of the specific
generator. if a unit is supplying residual voltage
only, either excitation current is not reaching the
rotor or the rotor windings are open and the excitation current cannot pass. on current units with
air-cooled engine, “field boost” current flow is
available to the rotor only during engine cranking.
teSt 4 – FiXed eXcitation teSt/
rotor amp draW teSt
DISCUSSION:
Supplying a fixed DC current to the rotor will induce a
magnetic field in the rotor. With the generator running,
this should create a proportional voltage output from
the stator windings.
Page 42
Figure 2. Voltage Regulator
4. Disconnect Wire 2 from the voltage regulator and connect one meter test lead to that wire. Disconnect Wire
6 from the voltage regulator and connect the other
meter test lead to that wire. Wires 2 and 6 are located
at the bottom two terminals of the voltage regulator
(see Figure 2).
5. Set the AUTO-OFF-MANUAL switch to MANUAL. Once
the engine starts, record the AC voltage.
6. Set the AUTO-OFF-MANUAL switch to OFF. Reconnect
Wire 2 and Wire 6.
7. Disconnect Wire 11 from the voltage regulator and connect one meter test lead to that wire. Disconnect Wire
22 from the voltage regulator and connect the other
meter test lead to that wire (both wires are located at the
top two terminals of the voltage regulator, see Figure 2).
8. Set the AUTO-OFF-MANUAL switch to MANUAL. Once
the engine starts, record the AC voltage.
9. Set the AUTO-OFF-MANUAL switch to OFF. Reconnect
Wire 11 and Wire 22.
10. Set VOM to DC amperage.
11. Remove jumper lead connected to Wire 4 and Wire 15B.
12. Connect one meter test lead to battery positive 12
VDC supply Wire 15B, located at TB1 terminal board.
AC GENERATORS
Part 2
Connect the other meter test lead to Wire 4 (still disconnected from previous tests). Measure and record
static rotor amp draw.
13. Set the AUTO-OFF-MANUAL switch to the MANUAL
position. Once the engine starts, repeat Step 12.
Measure and record running rotor amp draw with the
engine running.
14. Set the AUTO-OFF-MANUAL switch to OFF. Reconnect
Wire 4 to the voltage regulator.
RESULTS:
Refer to the chart on this page: “Results - Fixed
Excitation Test/Rotor Amp Draw Test”.
note: a calculated amp draw can be done by taking
the battery voltage that is applied divided by the
actual resistance reading of the rotor . a resistance
reading can be taken by measuring ohms between
Wires 4 and 0 at the voltage regulator.
These results match Column B in the chart. Refer
back to Problem 1 Flow Chart and follow Letter B.
1.75 - 1.17
1.75 - 1.17
Above 2.5A
Below 60 VACBelow 60 VACAbove 60 VACBelow 60 VAC
Below 60 VACBelow 60 VACAbove 60 VACBelow 60 VAC
Volts
Volts
Zero or Residual
Zero or Residual
sEctioN 2.4
DiaGNostic tEsts
1.75 - 1.17
1.59 - 1.07
1.59 - 1.07
Zero
Draw
Current
1.75 - 1.17
1.59 - 1.07
Above 2.5A
Above 2.3A
Zero
Draw
Current
1.39 - 0.93
1.59 - 1.07
1.39 - 0.93
Above 2.3A
Above 2.0A
Zero
1.75 - 1.17
1.75 - 1.17
Above 2.5A
Above 2.5A
Zero
Above 2.5A
Current
1.59 - 1.07
Above 2.5A
Current
Draw
1.59 - 1.07
1.39 - 0.93
Above 2.5A
Above 2.5A
Draw
è
teSt 5 – Wire continuity (12-20 kW)
DISCUSSION:
The voltage regulator receives unregulated alternating
current from the stator excitation winding, via Wires 2
and 6. It also receives voltage sensing from the stator AC power windings, via Wires 11 and 22. The
regulator rectifies the AC from the excitation winding
and based on the sensing signals, regulates the DC
current flow to the rotor. The rectified and regulated
current flow is delivered to the rotor brushes via Wires
4 (positive) and 0 (negative). This test will verify the
integrity of Wire 0.
PROCEDURE:
1. Set VOM to its “R x 1” scale.
2. Remove Wire 0 from the voltage regulator, 4th terminal
from the top. Also voltage regulator is labeled (-) next to
terminal.
3. Connect one test lead to Wire 0, connect the other test
lead to a clean frame ground. The meter should read
CONTINUITY.
RESULTS:
If CONTINUITY was not measured, repair or replace
the wire as needed.
teSt 4 results - Fixed excitation test/rotor amp draw test (12-20 kW)
ALLAbove 60 VACBelow 60 VACAbove 60 VAC
ALLAbove 60 VACAbove 60 VACBelow 60 VAC
Voltage Results
Voltage Results
Wire 2 & 6
results:(model #)aBcDEfGH
1.75 - 1.17
1.75 - 1.17
1.75 - 1.17
1.75 - 1.17
1.75 - 1.17
1.75 - 1.17
12 kW
14 kW
Wire 11 & 22
1.59 - 1.07
1.59 - 1.07
1.39 - 0.93
1.59 - 1.07
1.59 - 1.07
1.39 - 0.93
1.59 - 1.07
1.59 - 1.07
1.39 - 0.93
16 kW
17 kW
20 kW
Static Rotor
Amp Draw
1.75 - 1.17
1.75 - 1.17
1.75 - 1.17
1.75 - 1.17
1.75 - 1.17
1.75 - 1.17
12 kW
14 kW
Running Rotor
1.59 - 1.07
1.59 - 1.07
1.59 - 1.07
1.59 - 1.07
1.59 - 1.07
1.59 - 1.07
16 kW
17 kW
Amp Draw
Page 43
1.39 - 0.93
1.39 - 0.93
1.39 - 0.93
match reSultS With letter and reFer to FloW chart in Section 2.3 “problem 1”
ç
20 kW
5.54 VDC
LINE
WIRE 11 TEST POINT
WIRE 44 TEST POINT
LOAD
sEctioN 2.4
DiaGNostic tEsts
Part 2
AC GENERATORS
teSt 6 – check Field BooSt (12-20 kW)
DISCUSSION:
See “Field Boost Circuit” in Section 2.2. Field boost
current (from the circuit board) is available to the
rotor only while the engine is cranking. Loss of field
boost output to the rotor may or may not affect power
winding AC output voltage. The following facts apply:
induce a voltage into the DPE winding that is
high enough to turn the voltage regulator on,
regulator excitation current will be supplied
even if field boost has failed. Normal AC output
voltage will then be supplied.
sufficient to turn the regulator on, and field boost
has also been lost, excitation current will not be
supplied to the rotor. Generator AC output voltage
will then drop to zero or nearly zero.
6. Reconnect Wire 4.
RESULTS:
1. If normal field boost voltage is indicated in Step 6,
replace the voltage regulator.
2. If normal field boost voltage is NOT indicated in Step 6,
check Wire 4 (between regulator and circuit board) for
open or shorted condition. If wire is good, replace the
circuit board.
teSt 7 – teStinG the Stator With a Vom
(12-20 kW)
DISCUSSION:
A Volt-OHM-Milliammmeter (VOM) can be used to test
the stator windings for the following faults:
• Anopencircuitcondition
• A“short-to-ground”condition
• Ashortcircuitbetweenwindings
note: the resistance of stator windings is very
low. Some meters will not read such a low resistance, and will simply indicate continuity.
recommended is a high quality, digital type meter
capable of reading very low resistances.
PROCEDURE:
1. Disconnect Wire 4 from the voltage regulator, third
terminal from the top (see Figure 3).
2. Set a VOM to read DC volts.
3. Connect the positive (+) VOM test probe to the terminal
end of disconnected Wire 4.
4. C onnect the comm o n (- ) VOM test probe to the
grounding lug.
5. Crank the engine while observing the VOM reading.
While the engine is cranking, the VOM should read
approximately 4-6 Volts DC. When engine is not cranking, VOM should indicate “zero” volts (see Figure 3).
Page 44
Figure 3. Field Boost Test Points
Figure 4. Test 7 Test Points
PROCEDURE:
1. Isolate the generator from the transfer switch by disconnecting the load wires from the main breaker inside
the generator.
2. Disconnect Stator Leads 22 and 33 from the neutral
connection and separate the leads.
3. Disconnect and isolate Wires 2 and 6 and Wires 11 and 22
from the voltage regulator.
4. Make sure all of the disconnected leads are isolated
from each other and are not touching the frame during
the test.
AC GENERATORS
2
6
11P
44
33
22S (12-20 kW)
22P
11S (12-20 kW)
Part 2
sEctioN 2.4
DiaGNostic tEsts
5. Turn the Main Breaker to the "ON" or CLOSED position.
6. Set a VOM to measure resistance.
7. Connect one meter test lead to Wire 11 on the load side
of the main breaker. Connect the other meter test lead
to Wire 22 (power winding). Note the resistance reading and compare to the specifications in the front of this
manual.
8. Connect one test lead to stator lead Wire 44 on the load
side of the main breaker. Connect the other test lead to
stator lead Wire 33 (power winding). Note the resistance
reading and compare to the specifications in the front of
this manual.
note: Wire 11 and Wire 44 could be switched on
the main breaker. if an inFinity reading is indicated try putting the meter leads on the other
output terminal of the breaker. if inFinity is still
read then an actual fault may exist.
9. Connect one test lead to Wire 22 at the voltage regulator. Connect the other test lead to Wire 11 at the voltage
regulator (power winding sense leads). Note the resistance reading and compare to the specifications in the
front of this manual.
TEST WINDINGS FOR A SHORT TO GROUND:
10. Make sure all leads are isolated from each other and
are not touching the frame.
11. Connect one test lead to a clean frame ground. Connect
the other test lead to stator lead Wire 11 on the load
side of the main circuit breaker.
a. The meter should read INFINITY.
b. Any reading other than INFINITY indicates a
“short-to-ground” condition.
12. Repeat Step 11 using stator lead Wire 33.
13. Repeat Step 11 using Wire 22 at the voltage regulator.
14. Repeat Step 11 using Wire 6 at the voltage regulator.
TEST FOR A SHORT CIRCUIT BETWEEN WINDINGS:
15. Connect one test lead to stator lead Wire 11 on the load
side of the main circuit breaker. Connect the other test
lead to stator lead Wire 33.
a. The meter should read INFINITY.
b. Any reading other than INFINITY indicates a
short circuit between windings.
16. Repeat Step 15 using stator lead Wire 11; Wire 6.
17. Repeat Step 15 using stator lead Wire 33; Wire 6.
18. Repeat Step 15 using Wire 11 at the voltage regulator;
Wire 6 at the voltage regulator.
TEST CONTROL PANEL WIRES FOR CONTINUITY:
19. Connect one test lead to Wire 11 at the voltage regulator
and the other test lead at stator lead Wire 11
should be measured.
. Continuity
20. Connect one test lead to Wire 22 at the voltage regulator
and the other test lead at stator lead Wire 22
should be measured.
RESULTS:
. Continuity
1. Stator winding resistance values is a test of winding continuity and resistance. If a very high resistance or INFINITY
is indicated, the winding is open or partially open.
2. Testing for a “grounded” condition: Any resistance
reading indicates the winding is grounded.
3. Testing for a “shorted” condition: Any
reading
indicates the winding is shorted.
resistance
4. If the stator tests good and wire continuity tests good,
perform “Insulation Resistance Test” in Section 1.5.
5. If any test of wire continuity failed in the control panel,
repair or replace the wire, terminal or pin connectors for
that associated wire as needed.
note: read Section 1.5, “testing, cleaning and
drying” carefully. if the winding tests good, perform an insulation resistance test. if the winding
fails the insulation resistance test, clean and dry
the stator as outlined in Section 1.5. then, repeat
the insulation resistance test. if the winding fails
the second resistance test (after cleaning and
drying), replace the stator assembly.
Figure 5. Stator Assembly Leads
teSt 8 – teSt BruShleSS Stator
DISCUSSION:
The brushless stator has three internal windings,
two main power windings and a DPE winding. This
test will ensure that there are no shorts between the
power windings or shorts to ground.
A VOM meter can be used to test the stator windings
for the following faults:
Page 45
sEctioN 2.4
DiaGNostic tEsts
Part 2
AC GENERATORS
• Anopencircuitcondition
• A“short-to-ground”condition
• Ashortcircuitbetweenwindings
note: the resistance of stator windings is very low.
Some meters will not read such a low resistance,
and will simply indicate continuity. recommended
is a high quality, digital type meter capable of reading very low resistances.
PROCEDURE, 8 kW:
1. Disconnect Stator Leads 11 and 44 from the main circuit
breaker.
2. Disconnect Stator Leads 22 and 33 from the neutral
connection separate the leads.
3. Make sure all of the disconnected leads are isolated
from each other and are not touching the frame during
the test.
4. Set a VOM to measure resistance.
5. Connect one test lead to Stator Lead 11. Connect the
other test lead to Stator Lead 22. Note the resistance
reading and compare to the specifications in the front of
this manual.
6. Connect one test lead to Stator Lead 33. Connect the
other test lead to Stator Lead 44. Note the resistance
reading and compare to the specifications in the front of
this manual.
PROCEDURE, 10 kW:
1. Isolate the generator from the transfer switch by disconnecting the load wires from the main breaker inside
the generator.
2. Disconnect Stator Leads 22 and 33 from the neutral
connection and separate the leads.
3. Make sure all of the disconnected leads are isolated
from each other and are not touching the frame during
the test.
note: Wire 11 and Wire 44 could be switched on
the main breaker. if an inFinity reading is indicated try putting the meter leads on the other
output terminal of the breaker. if inFinity is still
read then an actual fault may exist.
TEST WINDINGS FOR A SHORT TO GROUND:
7. Make sure all leads are isolated from each other and are
not touching the frame.
8. Connect one test lead to a clean frame ground. Connect
the other test lead to stator lead Wire 11.
a. The meter should read INFINITY.
b. Any reading other than INFINITY indicates a
“short to ground” condition.
9. Repeat Step 7 using stator lead 44
TEST FOR A SHORT CIRCUIT BETWEEN WINDINGS:
10. Connect one test lead to stator lead 11. Connect the
other test lead to stator lead 33.
a. The meter should read INFINITY.
b. Any reading other that INFINITY indicates a
short between windings.
11. Repeat Step 10 using Wire 44.
RESULTS:
1. Stator winding resistance values is a test of winding continuity and resistance. If a very high resistance or INFINITY
is indicated, the winding is open or partially open.
2. Testing for a “grounded” condition: Any resistance
reading indicated the winding is grounded.
3. Testing for a “shorted” condition: Any resistance reading
indicated the winding is shorted.
4. If stator tests good and wire continuity tests good, refer
back to flow chart.
teSt 9 – check capacitor
4. Turn the Main Breaker to the "ON" or CLOSED position.
5. Set a VOM to measure resistance.
6. See Figure 4 for proper testing points. Connect one
meter test lead to Wire 11 on the load side of the main
breaker. Connect the other meter test lead to Wire 22
(power winding). Note the resistance reading and compare to the specifications in the front of this manual.
7. Connect one test lead to Stator Lead 44 on the load
side of the main breaker. Connect the other test lead
to Stator Lead 33 (power winding). Note the resistance
reading and compare to the specifications in the front of
this manual.
Page 46
DISCUSSION:
The brushless rotor system relies on the charging and
discharging of a capacitor to induce voltage into the
rotor and also to regulate voltage once 240 VAC is
achieved. If the capacitor fails, only residual magnetism
of the rotor will be measured at the Main Breaker .
Danger: the capacitor may need to be discharged before testing. a capacitor can be
*
discharged by crossing the terminals with
a metal insulated screw driver.
Danger: use proper protective equipment
when dealing with a capacitor that has
*
exploded.
AC GENERATORS
SET TO READ
CAPACITANCE
CAPACITOR
+
+
-
-
59.0
µf
Part 2
sEctioN 2.4
DiaGNostic tEsts
PROCEDURE:
1. Consult the owner’s manual of the meter being used for
directions on measuring capacitance. Figure 7 shows a
typical meter and how to check capacitance.
2. Connect the meter leads directly across the terminals of
the capacitor. The rated µf (micro farad) of the capacitor
is marked on the side of the canister.
3. The meter should display the correct µf reading ± 5µf.
If anything other than the indicated rating is displayed,
replace the capacitor.
a. A capacitor that has gone bad can have a
tendency to explode. Use caution when dealing with an exploded capacitor, the gel from
inside a capacitor can cause skin irritation.
b. A capacitor is defective if the terminal connec-
tions are loose on the canister.
c. A capacitor is defective if it wobbles while sitting
on a flat surface.
d. If any of the above observations are observed,
replace the capacitor.
teSt 10 – teSt dpe WindinG on
BruShleSS unitS
DISCUSSION:
A DPE winding or Displaced Phase Excitation wind-
ing is used to charge a capacitor that discharges and
charges releasing a voltage that is induced into the
rotor. If the DPE winding fails, only residual magnetism
of the rotor will be measured at the Main Breaker .
note: the resistance of stator windings is very
low. Some meters will not read such a low resistance, and will simply indicate continuity.
recommended is a high quality, digital type meter
capable of reading very low resistances.
Figure 6. Capacitor
RESULTS:
Figure 7. Field Boost Test Points
1. Refer back to flow chart
2. C ommon ob ser vatio n s can be made by visu a lly
inspecting the capacitor.
Warning: the capacitor may need to be
discharged before testing. a capacitor can
*
be discharged by crossing the terminals
with a metal insulated screw driver.
PROCEDURE:
1. Disconnect Wire 2 and Wire 6 from the capacitor.
2. Set VOM to measure resistance.
3. Connect one meter lead to Wire 2 and connect the other
meter lead to Wire 6.
a. Refer to the specifications in the front of this
manual for the correct resistance reading.
4. Connect one meter lead to Wire 2 and connect the other
meter lead to a clean frame ground, INFINITY should be
measured.
5. Disconnect Wires 11 and 44 from the main line circuit
breaker.
6. Disconnect Wire 22 and Wire 33 from the neutral connection
note: isolate all main stator leads before proceeding.
7. Connect one meter lead to Wire 2 and connect the other
meter lead to Wire 11. INFINITY should be measured.
8. Repeat Step 7 using Wires 2 and 44.
RESULTS:
1. Stator winding resistance values is a test of winding continuity and resistance. If a very high resistance or INFINITY
is indicated, the winding is open or partially open.
Page 47
0
4
-
+
sEctioN 2.4
DiaGNostic tEsts
Part 2
AC GENERATORS
2. Testing for a “grounded” condition: Any resistance
reading indicated the winding is grounded.
3. Testing for a “shorted” condition: Any resistance reading
indicated the winding is shorted.
4. If stator tests good and wire continuity tests good, refer
back to flow chart.
teSt 11 – reSiStance check oF
rotor circuit (12-20 kW)
DISCUSSION:
To verify the zero current draw reading and measure
the rotor circuit.
PROCEDURE:
1. Disconnect Wire 4 and Wire 0 from the voltage regulator,
located third and fourth terminals from the top of the
voltage regulator.
2. Set VOM to measure resistance.
3. Connect one test lead to Wire 4. Connect the other test
lead to a clean frame ground. Note the resistance reading.
Compare to specifications in the front of this manual.
RESULTS:
1. If the resistance reading is correct, check the VOM meter
fuse and repeat Test 4.
2. If INFINITY or a high reading is measured on the VOM,
refer back to flow chart.
teSt 12 – check BruSheS and Slip
rinGS (12-20 kW)
DISCUSSION:
The function of the brushes and slip rings is to provide
for passage of excitation current from stationary components to the rotating rotor. Brushes are made of a special long lasting material and seldom wear out or fail.
However, slip rings can develop a tarnish or film that
can inhibit or offer a resistance to the flow of electricity. Such a non-conducting film usually develops during
non-operating per iods. Broken or disconnected wiring
can also cause loss of excitation current to the rotor.
PROCEDURE:
1. See Figure 8. Carefully inspect brush wires; make sure
they are properly and securely connected.
2. Wire 0 from the negative (-) brush terminal connects
to Wire 0 at the voltage regulator. Test this wire for an
open condition. Remove Wire 0 from the brush assembly. Connect one meter test lead to Wire 0. Connect
the other test lead to Wire 0 at the voltage regulator.
Page 48
CONTINUITY should be measured. If INFINITY is
measured repair or replace Wire 0 between the brush
assembly and the voltage regulator.
Figure 8. Checking Brushes and Slip Rings
3. Wire 4 from the positive (+) brush terminal connects to
Wire 4 at the voltage regulator. Test this wire for an open
condition. Remove Wire 4 from the brush assembly.
Connect one meter test lead to Wire 4. Connect the
other meter test lead to Wire 4 at the voltage regulator. CONTINUITY should be measured. If INFINITY is
measured repair or replace Wire 4 between the brush
assembly and the voltage regulator.
4. Connect one meter test lead to Wire 4 Connect the
other meter test lead to frame ground. INFINITY should
be measured. If CONTINUITY is measured a short
to ground exists on Wire 4 repair or replace Wire 4
between the brush assembly and the voltage regulator.
5. If CONTINUITY was measured in Steps 5 and 6 proceed
to Step 9.
6. Disconnect Wire 0 and Wire 4 from the brush assembly.
Remove the brush assembly from the bearing carrier.
Inspect the brushes for excessive wear, or damage.
7. Inspect the rotor slip rings. If they appear dull or tarnished,
they may be polished with fine sandpaper. DO NOT USE
METALLIC GRIT TO POLISH SLIP RINGS.
8. If brush assembly and slip rings look good proceed to
Test 13 (Test Rotor Assembly)
9. Wire 0 connects from the voltage regulator in the control
panel ground lug. Connect one meter test lead to Wire 0
at the voltage regulator. Connect the other meter test lead
to the ground terminal in the control panel. CONTINUITY
should be measured. If INFINITY is measured repair or
replace Wire 0 between the voltage regulator and the
ground terminal.
10. Remove Wire 4 from the voltage regulator.
AC GENERATORS
SLIP RINGS
BEARING
Part 2
sEctioN 2.4
DiaGNostic tEsts
RESULTS:
1. Repair, replace or reconnect wires as necessary.
2. Replace any damaged slip rings or brush holder.
3. Clean and polish slip rings as required.
teSt 13 – teSt rotor aSSemBly
(12-20 kW)
DISCUSSION:
A rotor having completely open windings will cause
loss of excitation current flow and, as a result,
generator AC output voltage will drop to “residual”
voltage. A “shorted” rotor winding can result in a
low voltage condition.
PROCEDURE:
I. Disconnect the brush wires or remove the brush holder,
to prevent interaction.
2. Set a VOM to measure resistance.
3. Connect the positive (+) VOM test lead to the positive (+) rotor slip ring (nearest the rotor bearing); and
the common (-) test lead to the negative (-) slip ring.
The meter should read rotor resistance. Compare to
“Specifications,” in the front of this manual.
4. Connect the positive (+) VOM test lead to the positive (+)
slip ring and the common (-) test lead to a clean frame
ground. The meter should indicate INFINITY.
RESULTS:
1. Replace rotor assembly if it is open or shorted.
2. If rotor tests good, perform “Insulation Resistance Test”
in Section 1.5.
rotor if it fails that test. Then, repeat the test. If the rotor
fails the second insulation resistance test, it should be
replaced.
teSt 14 – check ac output Frequency
DISCUSSION:
The generator AC frequency is proportional to the
operating speed of the rotor. The 2-pole rotor will supply a 60 Hertz AC frequency at 3600 rpm. The unit’s
AC output voltage is proportional to the AC frequency.
For example, a unit rated 240 volts (line-to-line) will
supply that rated voltage (plus or minus 2 percent)
at a frequency of 60 Hertz. If, for any reason, the
frequency should drop to 30 Hertz, the line-to-line
voltage will drop to a matching voltage of 120 volts
AC. Thus, if the AC voltage output is high or low and
the AC frequency is correspondingly high or low, the
engine speed governor may require adjustment.
PROCEDURE:
1. Connect an accurate AC frequency meter across the
Wires 11 and 44 terminals of the generator main line
circuit breaker (see Figure 1, Section 2.4).
2. Start the engine, let it stabilize and warm up at no-load.
3. When engine has stabilized, read the frequency meter.
The no-load frequency for single cylinder units should
be about 62-63 Her tz. For V-Twin units, the no-load
frequency should be about 60 Hertz.
RESULTS:
1. If the AC frequency is high or low, go on to Test 15 for
single cylinder units, or Test 16 for V-Twin units.
2. If frequency is good, but voltage is high or low, go to
Test 17.
3. If frequency and voltage are both good, tests may be
discontinued.
Figure 9. The Rotor Assembly
NOTE: Be sure to read Section 1.5, “Testing, Cleaning
and Drying”, carefully. If the rotor tests good, try performing an insulation resistance test. Clean and dry the
teSt 15 – check and adjuSt enGine
GoVernor (SinGle cylinder unitS)
DISCUSSION:
The generator AC frequency output is directly pro-
portional to the speed of the rotor. A two-pole rotor
(having a single north and a single south magnetic
pole) will produce an AC frequency of 60 hertz at
3600 RPM.
The generator is equipped with a “voltage over frequency” type AC voltage regulator. The units AC
output voltage is generally proportional to AC frequency. A low or high governor speed will result in a
correspondingly low or high AC frequency and voltage
output. The governed speed must be adjusted before
any attempt to adjust the voltage regulator is made.
Page 49
GOVERNOR
SHAFT
PRIMARY
ADJUST
SCREW
GOVERNOR
CLAMP
BOLT
SECONDARY
ADJUST SCREW
sEctioN 2.4
DiaGNostic tEsts
PROCEDURE
(8 kW UNITS WITH DUAL GOVERNOR SPRINGS):
1. Loosen the governor clamp bolt (Figure 10).
2. Hold the governor lever at its wide open throttle position,
3. Start the generator; let it stabilize and warm up at
4. Connect a frequency meter across the generators AC
5. Turn the primary adjust screw to obtain a frequency
6. When frequency is correct at no load, check the AC
RESULTS:
1. If, after adjusting the engine governor, frequency and
2. If frequency is now good, but voltage is high or low, refer
3. If engine was overspeeding, check linkage and throttle
4. If engine appears to run rough and results in low fre-
Page 50
Figure 10. Engine Governor Adjustment Single
Cylinder Engines
and rotate the governor shaft clockwise as far as it will
go. Then, tighten the governor lever clamp bolt to 70
inch-pounds (8 N-m).
no-load.
output leads.
reading of 61.5 Hz. Turn the secondary adjust screw to
obtain a frequency reading of 62.5 Hz.
voltage reading. If voltage is incorrect, the voltage
regulator may require adjustment.
voltage are good, tests may be discontinued.
back to flow chart.
for binding. If no governor response is indicated refer to
engine service manual.
quency, proceed to Problem 18, Section 4.3.
Part 2
AC GENERATORS
teSt 16 – check Stepper motor
control (V-tWin enGine unitS)
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
pulling the stepper motor arm towards the idle stop. See
Figures 11 and 12 (for 9/10 kW units) or Figure 13 (for
12-20 kW Units).
4. Place the AUTO-OFF-MANUAL switch to MANUAL 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.
5. If no movement is seen in Step 4 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.
6. If problem continues the remove six pin connector from
the printed circuit board. Set Volt meter to measure
ohms. Carefully measure from the end of the six pin
harness as follows:
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.
RESULTS:
1. If the stepper motor fails any part of Step 6 replace the
stepper motor.
2. If the stepper motor passes all steps replace the Printed
Circuit Board.
STEPPER MOTOR
PULL ARM THIS
DIRECTION TO
CLOSE THROTTLE
STEPPER MOTOR
STEPPER MOTOR ARM
PULL ARM THIS
DIRECTION TO
CLOSE THROTTLE
STEPPER MOTOR
STEPPER MOTOR ARM
PULL ARM THIS
DIRECTION TO
CLOSE THROTTLE
RED
EMPTY
YELLOW
BROWN
ORANGE
BLACK
AC GENERATORS
Part 2
Figure 11. Throttle Positions 9/10 kW Units
sEctioN 2.4
DiaGNostic tEsts
Figure 14. Six Pin Connector Wire Colors
teSt 17 – check and adjuSt VoltaGe
reGulator (12-20 kW)
DISCUSSION:
For additional information, refer to description and
components Section 2.1.
Figure 12. Throttle Positions 9/10 kW Units
PROCEDURE (V-TWIN ENGINE UNITS):
With the frequency at 60 Hertz, slowly turn the
slotted potentiometer (Figure 15) until line voltage
reads 247-249 volts.
note: the access panel on top of the control panel
must be removed to adjust the voltage regulator.
note: the voltage regulator is housed in the
back of the generator control panel. the regulator maintains a voltage in direct proportion to
frequency at a 2-to-1 ratio. For example, at 60
hertz, line-to-neutral voltage will be 120 volts.
Figure 13. Throttle Positions 12-20 kW Units
Figure 15. Voltage Adjustment Potentiometer
RESULTS:
1. If the frequency and voltage are now good, discontinue tests.
2. If frequency is now good but voltage is high or low, refer
back to flow chart.
Page 51
sEctioN 2.4
DiaGNostic tEsts
Part 2
AC GENERATORS
teSt 18 – check VoltaGe and
Frequency under load
DISCUSSION:
It is possible for the generator AC output frequency
and voltage to be good at no-load, but they may drop
excessively when electrical loads are applied. This
condition, in which voltage and frequency drop excessively when loads are applied, can be caused by (a)
overloading the generator, (b) loss of engine power, or
(c) a shorted condition in the stator windings or in one
or more connected loads.
PROCEDURE:
1. Connect an accurate AC frequency meter and an AC
voltmeter across the stator AC power winding leads.
2. Start the engine, let it stabilize and warm-up.
3. Apply electrical loads to the generator equal to the rated
capacity of the unit.
4. Check the AC frequency and voltage.
a. Single Cylinder Units: Frequency should not
drop below approximately 58 Hertz. Voltage
should not drop below about 230 volts.
b. V-Twin Engine Units: Frequency should not drop
below approximately 60 Hertz. Voltage should
not drop below about 240 volts.
RESULTS:
1. If frequency and voltage drop excessively under load,
refer back to flow chart.
2. If frequency and voltage under load are good, discontinue tests.
teSt 19 – check For oVerload
condition
DISCUSSION:
An “overload” condition is one in which the generator
rated wattage/amperage capacity has been exceeded. To test for an overload condition on an installed
unit, the best method is to use an ammeter. See
“Measuring Current” in Section 1.5.
PROCEDURE:
Use a clamp-on ammeter to measure load current draw, with
the generator running and all normal electrical loads turned on.
RESULTS:
1. If the unit is overloaded, reduce loads to the unit’s rated
capacity.
2. If unit is not overloaded, but rpm and frequency drop
excessively when loads are applied, go to Test 16.
teSt 20 – check enGine condition
DISCUSSION:
If engine speed and frequency drop excessively
under load, the engine may be under-powered. An
under-powered engine can be the result of a dirty air
cleaner, loss of engine compression, faulty fuel settings, incorrect ignition timing, etc.
PROCEDURE:
For engine testing, troubleshooting and repair
procedures refer to Problem 11 in Section 4.3.
For fur ther engine repair information refer to the
appropriate engine service manuals
.
teSt 21 – Field FlaSh alternator
(8-10 kW unitS)
DISCUSSION:
The alternator utilizes residual magnetism within the
windings to charge the capacitor. If the generator has
been sitting for a long period of time with no activity
the residual magnetism could be lost within the rotor.
Field flashing the rotor while connected in parallel with
the capacitor will force a charge of electricity through
the DPE winding. The voltage that is induced into the
rotor will return and charge the capacitor enough to
take over voltage regulation of the unit.
note: it is crucial that the generator exercise once
a week to help maintain this residual magnetism.
Warning:
performing this test.
*
PROCEDURE:
1. Construct an energizing cord that is similar to that shown
in Figure 17 and connect it as shown in Figure 18.
2. Set the AUTO-OFF-MANUAL switch to the OFF position.
Warning:
more than 1 second at a time.
*
3. Momentarily turn on the energizing cord (one second).
4. Disconnect the energizing cord from the capacitor.
5. If the field flash was successful, the generator should
now be producing approximately 240 VAC at the main
circuit breaker of the generator when the AUTO-OFFMANUAL is set to the MANUAL position.
Warning:
than two times in sequence. if the unit has
*
not produced power after two attempts, other
issues exist and need to be addressed.
RESULTS:
1. Refer back to flow chart.
Please keep safety in mind while
Do Not energize the capacitor for
Do not field flash alternator more
Page 52
GENERATOR
CAPACITOR
WIRES 2 & 6 TO
DPE WINDING
DEPRESS SWITCH FOR
ONE SECOND
PLUG ENERGIZING CORD
INTO AC OUTLET
CAPICITOR REMAINS CONNECTED
TO GENERATOR
Danger: The capacitor may need to be discharged before testing. A capacitor can be
discharged by crossing the terminals with a
metal insulated screw driver.
Danger: Use proper protective equipment
when dealing with a capacitor that has
exploded.
12 AWG
12 AWG
MOMENTARY PUSHBUTTON ON/OFF SWITCH
SINGLE POLE SWITCH ON LIVE SIDE
DO NOT SUBSTITUTE ANY OTHER DEVICE
4 ft.
CRIMP ON STANDARD FEMALE BLADE CONNECTORS
STANDARD MALE PLUG
AC GENERATORS
Part 2
sEctioN 2.4
DiaGNostic tEsts
Figure 17. Construction of Energizing Cord
Figure 18. Energizing Cord Connection
Page 53
NotEs
Page 54
Part 3
taBlE of coNtENts
ParttitlEPG#
3.1.Description and components50
3.2operational analysis54
3.3troubleshooting flow charts64
traNsfEr
sWitcH
air-cooled, automatic
standby Generators
3.1 Description and Components ...............................................56
Introduction To Troubleshooting ..........................................70
Problem 7 – In Automatic Mode,
No Transfer to Standby ..................................................70
Problem 8 – In Automatic Mode, Generator
Starts When Loss of Utility Occurs,
Generator Shuts Down When Utility
Returns But There Is No Retransfer To Utility Power / or
Generator Transfers to Standby During Exercise Or In
“Load Shed Transfer Switch” ...............................92
Test 50 – Check Battery Charger
Output Voltage
“Load Shed Transfer Switch” ...............................92
Test 51 – Check Wire 0 and Wire 15B
“Load Shed Transfer Switch” ...............................94
Page 55
31
17
26
ITEMS 32-37
38
18
27
3A
3B
13
8
14
12
39
20
15
19
26
26
2
3
5
11
6
4
9
7
10
24
23
16
21
22
22
9
16
23
29
1
30
sEctioN 3.1
DEscriPtioN & comPoNENts
Part 3
TRANSFER SWITCH
General
The “W/V-Type” transfer switch is rated 100 amps at
250 volts maximum. It is available in 2-pole configuration only and, for that reason, is usable with 1-phase
systems only.
Transfer switches do not have an intelligence system of their own. Instead, automatic operation of
these transfer switches is controlled by a circuit board
housed in the generator control panel.
The “W/V-Type” transfer switch enclosure is a NEMA
1 type (“NEMA” stands for “National Electrical
Manufacturer’s Association”). Based on NEMA
Standard 250, the NEMA 1 enclosure may be defined
as one that is intended for indoor use primarily to
provide a degree of protection against contact with
the enclosed equipment and where unusual service
conditions do not exist.
Page 56
Figure 1. Exploded View of W/V-Type Transfer Switch
TRANSFER SWITCH
STANDBY
LOAD
UTILITY
STANDBY
LOAD
UTILITY
UTILITY
CLOSING
COIL (C1)
STANDBY
CLOSING
COIL (C2)
BRIDGE
RECTIFIER
BRIDGE
RECTIFIER
MANUAL
TRANSFER
LEVER
LIMIT
SWITCH
(SW2)
N1
N2
E2
E1
T1
LIMIT
SWITCH
(SW3)
T2
N2A A
A
B
126
205
B
E2
Part 3
sEctioN 3.1
DEscriPtioN & comPoNENts
tranSFer mechaniSm
The 2-pole transfer mechanism consists of a pair
of moveable LOAD contacts, a pair of stationary
UTILITY contacts, and a pair of stationary STANDBY
contacts. The load contacts can be connected to
the utility contacts by a utility closing coil; or to the
standby contacts by a standby closing coil. In addition, the load contacts can be actuated to either the
UTILITY or STANDBY side by means of a manual
transfer handle. See Figures 2 and 3.
Figure 2. Load Connected to Utility Power Source
source side. Energizing the coil moves the load contacts to an overcenter position; limit switch action then
opens the circuit and spring force will complete the
transfer action to “Standby”. This coil’s bridge rectifier
is also sealed in the coil wrappings. Replace the coil
and bridge rectifier as a unit.
LIMIT SWITCHES SW2 AND SW3:
Switches are mechanically actuated by load contacts
movement. When the load contacts are connected to
the utility contacts, limit switch SW2 opens the utility
circuit to utility closing coil C1 and limit switch SW3
closes the standby circuit to standby closing coil C2.
The limit switches “ar m” the system for retransfer
back to UTILITY when the load contacts are connected to the STANDBY side. Conversely, when the
load contacts are connected to the UTILITY side, the
switches “arm” the system for transfer to STANDBY.
An open condition in limit switch SW2 will prevent
retransfer to “Utility”. An open switch SW3 will prevent
transfer to STANDBY.
Figure 3. Load Connected to Standby Power Source
UTILITY CLOSING COIL C1:
See Figure 4. This coil is energized by rectified util-
ity source power, to actuate the load contacts to the
UTILITY power source side. When energized, the coil
will move the main contacts to an “overcenter” position. A limit switch will then be actuated to open the
circuit and spring force will complete the retransfer to
STANDBY. A bridge rectifier, which changes the utility
source alternating current (AC) to direct current (DC),
is sealed in the coil wrappings. If coil or bridge rectifier
replacement becomes necessary, the entire coil and
bridge assembly should be replaced.
STANDBY CLOSING COIL C2:
Coil C2 is energized by rectified standby source
power, to actuate the load contacts to their “Standby”
Figure 4. The “W/V-Type” Transfer Mechanism
tranSFer relay
Transfer relay operation is controlled by a circuit
board. That circuit board is a part of a control panel
assembly, mounted on the standby generator set.
Figure 5 shows the transfer relay pictorially and
schematically. Relay operation may be briefly
described as follows:
1. Generator battery voltage (12 volts DC) is available to
the transfer relay coil from the generator circuit board,
via Wire 15B and Relay Terminal A.
a. The 12 volts DC circuit is completed through
the transfer relay coil and back to the generator
circuit board, via Wire 23.
b. Circuit board action normally holds the Wire
23 circuit open to ground and the relay is
de-energized.
Page 57
1
69
7
A
B
23
194
N1A
E1
126
205
015B23
sEctioN 3.1
DEscriPtioN & comPoNENts
Part 3
TRANSFER SWITCH
c. When de-energized, the relay’s normally open
contacts are open and its normally-closed
contacts are closed.
d. The normally-closed relay contacts will deliver
utility source power to the utility closing circuit
of the transfer mechanism.
e. The normally open relay contacts will deliver
standby source power to the transfer mechanism’s standby closing circuit.
neutral luG
The standby generator is equipped with an
UNGROUNDED neutral. The neutral lug in the transfer
switch is isolated from the switch enclosure .
manual tranSFer handle
The manual transfer handle is retained in the transfer
switch enclosure by means of a wing stud. Use the
handle to manually actuate the transfer mechanism
load contacts to either the UTILITY or STANDBY
source side.
Instructions on use of the manual transfer handle
may be found in Part 5, “Operational Tests and
Adjustments”.
terminal Block
During system installation, this 3-point terminal block
must be properly interconnected with an identically
labeled terminal block in the generator control panel
assembly.
Figure 5. Transfer Relay Schematic
2. During automatic system operation, when the generator circuit board “senses” that utility source voltage
has dropped out, the circuit board will initiate engine
cranking and startup.
3. When the circuit board “senses” that the engine has
started, an “engine warm-up timer” on the circuit board
starts timing.
4. When the “engine warm-up timer” has timed out,
circuit
board action completes the Wire 23 circuit to ground.
a. The transfer relay then energizes.
b. The relay’s normally-closed contacts open and
its normally open contacts close.
c. When the normally open contacts close, standby
source power is delivered to the standby closing
coil and transfer to “Standby” occurs.
5. When the generator circuit board “senses” that utility
source voltage has been restored above a preset level,
the board will open the Wire 23 circuit to ground.
a. The transfer relay will de-energize, its normally-
closed contacts will close and its normally open
contacts will open.
b. When the normally-closed relay contacts close,
utility source voltage is delivered to the utility
closing coil to energize that coil.
c. Retransfer back to UTILITY occurs.
Page 58
Figure 6. Transfer Switch Terminal Block
Terminals used on the terminal block are identified as
0, 15B and 23.
UTILITY N1 AND N2:
Interconnect with identically labeled terminals in the
generator control panel assembly. This is the utility
voltage signal to the circuit board. The signal is delivered to a step-down transformer in the control module
assembly and the resultant reduced voltage is then
delivered to the circuit board. Utility 1 and 2 power is
used by the circuit board as follows:
• If utility source voltage should drop below a preset level, circuit board action will initiate automatic
cranking and startup, followed by automatic transfer
to the standby source.
Figure 3 is a schematic representation of the transfer switch with utility source power available. The circuit
condition may be briefly described as follows:
If utility source voltage should drop below a preset value, the generator circuit board will sense the dropout. The
circuit board will then initiate generator cranking and startup after a time delay circuit times out.
Figure 4 is a schematic representation of the transfer switch with generator power available, waiting to transfer.
12 VDC is delivered to the transfer relay via Wire 15B and back to the circuit board via Wire 23. However, circuit
board action holds the Wire 23 circuit open and the transfer relay remains de-energized. On generator startup, an
“engine warm-up timer” on the generator circuit board starts timing. When that timer has timed out, circuit board
action completes the Wire 23 circuit to ground. The transfer relay then energizes, its normally open contacts
close, and standby source voltage is delivered to the standby closing coil via Wires E1 and E2, the transfer relay
(TR1) contacts, limit switch (SW3), Wire “B”, and a bridge rectifier. The standby closing coil energizes and the
main contacts actuate to their “Standby” side.
When the standby coil is energized it pulls the transfer switch mechanism to a overcenter position towards the
standby power source side, the transfer switch mechanically snaps to the standby position. On closure of the
main contacts to the standby power source side, limit switches SW2 and SW3 are mechanically actuated to “arm”
the circuit for re- transfer to utility power source side.
Generator power from E1 and E2 is now connected to the customer load through T1 and T2.
Utility voltage is restored and is available to Terminals N1 and N2. The utility voltage is sensed by the generators
circuit board. If it is above a preset value for a preset time interval a transfer back to utility power will occur.
Figure 7. Utility Restored, Generator Still Providing Output to Load.
After the preset time interval expires the circuit board will open the Wire 23 circuit to ground. The transfer relay
de-energizes, it’s normally closed contacts close, and utility source voltage is delivered to the utility closing coil
(C1), via Wires N1A and N2A, closed Transfer Relay Contacts 1 and 7, and Limit Switch SW2.
Part 3
utility reStored, tranSFer SWitch de-enerGized
Figure 8. Utility Restored, Transfer Relay De-energized.
As the utility coil pulls the transfer switch to an OVER CENTER position, the switch mechanically snaps to Utility.
On closure of the main contacts to the utility power source side, Limit Switches SW2 and SW3 are mechanically
actuated to “arm” the circuit for transfer to standby.
Page 68
Part 3
utility reStored, retranSFer Back to utility
Figure 9. Utility Restored, Retransfer Back to Utility.
When the transfer switch returns to the utility side, generator shutdown occurs after approximately one (1) minute.
Part 3
sEctioN 3.2
oPEratioNal aNalYsis
tranSFer SWitch in utility
Page 69
Figure 10. Transfer Switch in UTILITy.
BAD
BAD
REPAIR OR REPLACE AS NEEDED
REPLACE
GOOD
GOOD
GOOD
FIND CAUSE OF NO AC OUTPUT TO
TRANSFER SWITCH FROM GENERATOR
TEST 26 – CHECK
VOLTAGE AT
TERMINAL LUGS
E1 & E2
TEST 27 – CHECK
MANUAL TRANSFER
SWITCH OPERATION
TEST 28 – CHECK #23
AND #15B WIRING
CONNECTIONS
BAD
REPAIR AS NEEDED
TEST 30 – CHECK
STANDBY CONTROL
CIRCUIT
TEST 29 – TEST
TRANSFER
RELAY
BAD
BAD
GOOD
REPAIR OR REPLACE MECHANISM
Problem 7 – In Automatic Mode, No Transfer to Standby
sEctioN 3.3
Part 3
TRANSFER SWITCH
trouBlEsHootiNG floW cHarts
introduction to trouBleShootinG
The first step in troubleshooting is to correctly identify the problem. Once that is done, the cause of the an be
found by performing the tests in the appropriate flow chart.
Test numbers assigned in the flow charts are identical to test numbers in Section 3.4, “Diagnostic Tests.” Section
3.4 provides detailed instructions for performance of each test.
Page 70
TRANSFER SWITCH
Problem 8 – In Automatic Mode, Generator Starts When Loss of Utility Occurs, Generator
Shuts Down When Utility Returns But There Is No Retransfer To Utility Power
OR
Generator Transfers to Standby During Excercise or in Manual Mode
BAD
BAD
REPAIR OR REPLACE AS NEEDED
REPAIR OR REPLACE AS NEEDED
REPLACE
GOOD
GOOD
GOOD
TEST 27 – CHECK
MANUAL TRANSFER
SWITCH OPERATION
TEST 31 – CHECK
WIRE 23
BAD
TEST 32 – CHECK
UTILITY CONTROL
CIRCUIT
TEST 29 – TEST
TRANSFER
RELAY
BAD
REPAIR OR REPLACE MECHANISM
TEST 34 – CHECK
FUSE F1 & F2
TEST 35 – CHECK
N1 & N2 WIRING
GOOD
GOOD
BAD
BAD
REPAIR OR REPLACE
WIRING
INSPECT/REPLACE
PRINTED CIRCUIT BOARD
FINISH
Problem 9 – Blown F1 or F2 Fuse
Part 3
sEctioN 3.3
trouBlEsHootiNG floW cHarts
Page 71
REPLACE
CIRCUIT
BOARD
CORRECT
UTILITY
SOURCE
VOLTAGE
REPLACE
GO TO PROBLEM 7
REPAIR OR
REPLACE
WIRING
REPAIR OR REPLACE WIRE
N1A/N2A BETWEEN N1/N2
LUGS AND FUSE HOLDER
REPAIR N1/N2 OPEN WIRING
BETWEEN TRANSFER
SWITCH AND GENERATOR
Problem 10 – Unit Starts and Transfer Occurs When Utility Power Is On
8 kW: Green LED Flashes
10-20 kW: Status – Utility Lost
TEST 37 – CHECK
UTILITY SENSING
VOLTAGE AT
CIRCUIT BOARD
TEST 36 –
CHECK N1 & N2
VOLTAGE
TEST 38 – CHECK
UTILITY SENSE
VOLTAGE
TEST 39 –
CHECK VOLTAGE
AT TERMINAL
LUGS N1 & N2
TEST 34 –
CHECK FUSE
F1 & F2
GOOD
GOOD
GOOD
GOOD
GOOD
BAD
BAD
BAD
BAD
BAD
sEctioN 3.3
trouBlEsHootiNG floW cHarts
Part 3
TRANSFER SWITCH
Page 72
REPLACE PRINTED
CIRCUIT BOARD
REPAIR OR REPLACE
REPLACE CHARGER
Problem 11 – No Battery Charge
“Pre-Wire Load Center”
TEST 40 – CHECK
BATTERY CHARGER
SUPPLY VOLTAGE
TEST 41 – CHECK
BATTERY CHARGER
OUTPUT VOLTAGE
TEST 42 – CHECK
WIRE 0/15B
GOOD
GOOD
BAD
REPAIR OR
REPLACE
BAD
BAD
NO BATTERY
SUPPLY VOLTAGE
REPLACE PRINTED
CIRCUIT BOARD
REPAIR OR REPLACE
REPLACE CHARGER
Problem 12 – No Battery Charge
“RTSN & RTSE Transfer Switch”
TEST 43 – CHECK
BATTERY CHARGER
SUPPLY VOLTAGE
TEST 44 – CHECK
BATTERY CHARGER
OUTPUT VOLTAGE
TEST 45 – CHECK
WIRE 0/15B
GOOD
GOOD
BAD
REPAIR OR
REPLACE
BAD
BAD
NO BATTERY
SUPPLY VOLTAGE
REPLACE PRINTED
CIRCUIT BOARD
REPAIR OR REPLACE
REPLACE CHARGER
Problem 13 – No Battery Charge
“GenReady Load Center”
TEST 46 – CHECK
BATTERY CHARGER
SUPPLY VOLTAGE
TEST 47 – CHECK
BATTERY CHARGER
OUTPUT VOLTAGE
TEST 48 – CHECK
WIRE 0/15B
GOOD
GOOD
BAD
REPAIR OR
REPLACE
BAD
BAD
NO BATTERY
SUPPLY VOLTAGE
REPLACE PRINTED
CIRCUIT BOARD
REPAIR OR REPLACE
REPLACE CHARGER
Problem 14 – No Battery Charge
“Load Shed Transfer Switch”
TEST 49 – CHECK
BATTERY CHARGER
SUPPLY VOLTAGE
TEST 50 – CHECK
BATTERY CHARGER
OUTPUT VOLTAGE
TEST 51 – CHECK
WIRE 0/15B
GOOD
GOOD
BAD
REPAIR OR
REPLACE
BAD
BAD
NO BATTERY
SUPPLY VOLTAGE
TRANSFER SWITCH
Part 3
sEctioN 3.3
trouBlEsHootiNG floW cHarts
Page 73
UTILITY
CLOSING
COIL (C1)
STANDBY
CLOSING
COIL (C2)
BRIDGE
RECTIFIER
BRIDGE
RECTIFIER
MANUAL
TRANSFER
LEVER
LIMIT
SWITCH
(SW2)
N1
N2
E2
E1
T1
LIMIT
SWITCH
(SW3)
T2
N2AA
A
B
126
205
B
E2
sEctioN 3.4
DiaGNostic tEsts
Part 3
TRANSFER SWITCH
General
Test numbers in this section correspond to the
numbered tests in Section 3.3, “Troubleshooting
Flow Charts”. When troubleshooting, first identify
the problem. Then, perform the diagnostic tests in
the sequence given in the flow charts.
teSt 26 – check VoltaGe at terminal
luGS e1, e2
DISCUSSION:
In automatic mode, the standby closing coil (C2) must
be energized by standby generator output if transfer to
the “Standby” source is to occur. Transfer to “Standby”
cannot occur unless that power supply is available to
the transfer switch.
DaNGEr: BE carEful! HiGH aND
DaNGErous VoltaGEs arE PrEsENt
*
at tErmiNal luGs E1 aND E2 WHEN
tHE GENErator is ruNNiNG. aVoiD
coNtact WitH HiGH VoltaGE tErmiNals
or DaNGErous aND PossiBlY lEtHal
ElEctrical sHocK maY rEsult. Do
Not PErform tHis VoltaGE tEst WHilE
staNDiNG oN WEt or DamP GrouND,
WHilE BarEfoot, or WHilE HaNDs or
fEEt arE WEt.
PROCEDURE:
1. If the generator engine has started automatically (due to
a utility power source outage) and is running, check the
position of the generator main circuit breaker. The circuit
breaker must be set to its “On” or “Closed” position.
After confirming that the generator main circuit breaker
is set to ON (or closed), check the voltage at transfer
mechanism Terminal Lugs E1 and E2 with an accurate
AC voltmeter or with an accurate volt-ohm-milliammeter
(VOM). The generator line-to line voltage should be
indicated.
2. If the generator has been shut down, proceed as follows:
a. On the generator control panel, set the AUTO-
OFF-MANUAL switch to OFF.
b. Turn off all power voltage supplies to the trans-
fer switch. Both the utility and standby power
supplies must be positively turned off before
proceeding.
c. Check the position of the transfer mechanism
main contacts. The moveable LOAD contacts must
be connected to the stationary UTILITY source
contacts. If necessary, manually actuate the main
contacts to the “Utility” power source side.
d. Actuate the generator main line circuit breaker
to its “On” or “Closed” position. The utility power
supply to the transfer switch must be turned off.
Page 74
Figure 1. The Transfer Mechanism
TRANSFER SWITCH
MANUAL
TRANSFER
HANDLE
TRANSFER
SWITCH
OPERATING
LEVER
MANUAL
TRANSFER
HANDLE
TRANSFER
SWITCH
OPERATING
LEVER
LOAD CONNECTED TO
UTILITY POWER SOURCE
LOAD CONNECTED TO
STANDBY POWER SOURCE
Part 3
sEctioN 3.4
DiaGNostic tEsts
e. Set the generator AUTO-OFF-MANUAL switch
to AUTO.
(1) The generator should crank and start.
(2) When the generator starts, an “engine
warm-up timer” should start timing. After
about 15 seconds, the transfer relay should
energize and transfer to the “Standby”
source should occur.
f. If transfer to “Standby” does NOT occur, check
the voltage across transfer switch Terminal Lugs
E1 and E2. The generator line-to-line voltage
should be indicated.
RESULTS:
1. If normal transfer to “Standby” occurs, discontinue tests.
2. If transfer to “Standby” does NOT occur and no voltage
is indicated across Terminal Lugs E1/E2, determine why
generator AC output has failed.
3. If transfer to “Standby” does NOT occur and voltage
reading across Terminal Lugs E1/E2 is good, refer to
Flow Chart.
teSt 27 – check manual tranSFer
SWitch operation
DISCUSSION:
In automatic operating mode, when utility source volt-
age drops below a preset level, the engine should
crank and start. On engine startup, an “engine warm-up
timer” on the generator circuit board should start timing.
When that timer has timed out (about 15 seconds), the
transfer relay should energize to deliver utility source
power to the standby closing coil terminals. If normal
utility source voltage is available to the standby closing
coil terminals, but transfer to Standby does not occur,
the cause of the failure may be (a) a failed standby
closing coil and/or bridge rectifier, or (b) a seized or
sticking actuating coil or load contact. This test will help
you evaluate whether any sticking or binding is present
in the transfer mechanism.
PROCEDURE:
1. With the generator shut down, set the generator
AUTO-OFF-MANUAL switch to OFF.
2. Set the generator main circuit breaker to OFF or “Open”.
3. Turn off the utility power supply to the transfer switch,
using whatever means provided (such as a utility source
main line breaker).
DaNGEr: Do Not attEmPt maNual
*
traNsfEr sWitcH oPEratioN uNtil
all PoWEr VoltaGE suPPliEs to tHE
sWitcH HaVE BEEN PositiVElY turNED
off. failurE to turN off all PoWEr
VoltaGE suPPliEs maY rEsult iN
EXtrEmElY HaZarDous aND PossiBlY
lEtHal ElEctrical sHocK.
4. In the transfer switch enclosure, locate the manual
transfer handle. Handle is retained in the enclosure
with a wing nut. Remove the wing nut and handle.
5. See Figure 2. Insert the un-insulated end of the handle
over the transfer switch operating lever.
a. Move the transfer switch operating lever up to
actuate the load contacts to the Utility position,
i.e., load connected to the utility source.
Figure 2. Manual Transfer Switch Operation
Page 75
sEctioN 3.4
DiaGNostic tEsts
Part 3
TRANSFER SWITCH
b. Actuate the operating lever down to move the
load contacts against the standby contacts, i.e.,
load connected to the Standby source.
6. Repeat Step 5 several times. As the transfer switch
operating lever is moved slight force should be needed
until the lever reaches its center position. As the lever
moves past its center position, an over-center spring
should snap the moveable load contacts against the
stationary STANDBY or UTILITY contacts.
7. Finally, actuate the main contacts to their UTILITY power
source side, i.e., load contacts against the UTILITY contacts
(upward movement of the operating lever).
RESULTS:
1. If there is no evidence of binding, sticking, or excessive
force required, refer back to flow chart.
2. If evidence of sticking, binding, excessive force required
to move main contacts, find cause of binding or sticking
and repair or replace damaged part(s).
teSt 28 – check 23 and 15B WirinG/
connectionS
DISCUSSION:
An open circuit in the transfer switch control wir-
ing can prevent a transfer action from occurring.
Battery voltage +12 VDC is supplied on Wire 15B.
This DC voltage is supplied to the transfer relay (TR)
at Terminal Location “A”. The opposite side of the
transfer relay (TR) coil (Terminal B) is connected
to Wire 23. Positive 12 VDC is present on this also.
Circuit board action will allow current to flow through
the circuit and the (TR) is energized.
PROCEDURE/ RESULTS:
Refer to Figure 3.
1. Remove transfer relay mounting screws so that contact
movement can be visually observed.
2. Set the generator AUTO-OFF-MANUAL switch to the
AUTO position. Turn off utility power supply to the
transfer switch, simulating a utility failure. Visually
watch the transfer relay for contact movement. The
relay should be energized and contact movement seen
approximately 10 seconds after the generator starts.
a. If the transfer relay energizes, discontinue
testing. Refer to flow chart.
b. If the transfer relay does not energize, continue
to Step 3.
3. Set the generator AUTO-OFF-MANUAL switch to the
OFF position.
4. Remove the battery charger fuse (F3) from the transfer
switch to disable the battery charge circuit.
Page 76
caution: after removing the fuse fr om the battery charger, wait 5 minutes before proceeding.
*
5. Set VOM to measure DC voltage.
6. Connect the negative (-) test lead to Wire 0 at the terminal strip in the transfer switch. Connect the positive (+)
test lead to Wire 15B at the terminal strip in the transfer
switch.
a. If voltage is present, proceed to Step 7.
b. If voltage is not present proceed to Step 17.
7. Connect the positive (+) test lead to Wire 23 at the terminal strip in the transfer switch.
a. If voltage is present, proceed to Step 8.
b. If voltage is not present, set VOM to measure
resistance.
c. Remove Wire 23 and Wire 15B going to the
transfer relay from the transfer switch terminal
strip. Connect the meter test leads across Wire
23 and Wire 15B.
d. Transfer coil resistance of approximately 115
ohms should be measured.
e. If coil resistance is not measured, remove
Wire 23 and Wire 15B from the transfer relay.
Measure across Terminal A and Terminal B of
the transfer relay.
f. If coil resistance is measured repair or replace
Wire 23 or Wire 15B between the terminal strip
and the transfer relay.
g. If coil resistance is not measured replace trans-
fer relay and retest.
8. Connect the negative (-) test lead to the ground lug in
the generator control panel. Connect the positive (+)
test lead to Wire 23 in the generator control panel at the
terminal strip.
a. If voltage is present, proceed to Step 9.
b. If voltage is not present, repair wiring between
transfer switch and generator control panel.
9. Remove the J2 connector from the circuit board.
10. Set VOM to measure resistance.
11. Connect one meter test lead to Wire 23 Pin Location
J2-5. Connect the other meter test lead to Wire 15B
Pin Location J2-8. Approximately 115 ohms should be
measured. (see Figures 4 through 7, Section 4.1).
a. If approximately 115 ohms is measured proceed
to Step 12.
b. If infinity or an open is measured, repair Wire 23
between PCB Connector J2 and the generator
terminal strip.
c. If resistance is not within specification, go to
Test 29 – Test Transfer Relay.
12. Reconnect the J2 connector to the PCB.
TRANSFER SWITCH
15B
COIL NOMINAL RESISTANCE = 120 Ohms
N1A
126
205
E1
23
Part 3
sEctioN 3.4
DiaGNostic tEsts
13. Set VOM to measure DC voltage.
14. Connect the (-) negative meter test lead to Wire 0 at the
terminal strip in the generator. Connect the (+) positive
meter test lead to Wire 23 at the terminal strip in the
generator. 12 VDC should be measured.
15. Place generator AUTO-OFF-MANUAL switch to the
AUTO position. Turn off utility power supply to the
transfer switch, simulating a utility failure. After the
generator star ts 10 seconds should elapse before
transfer occurs. At that time the VOM DC voltage
should drop to zero. This indicates the PCB energized
the transfer relay.
a. If DC voltage drops to zero, refer to Flow Chart.
b. If DC voltage remains constant at 12 VDC, pro-
ceed to Step 16.
16. With the generator running and utility off, ground Wire 23
in the control panel at the terminal strip. If transfer relay
energizes and or transfer occurs, replace the PCB.
17. Set VOM to measure DC voltage.
18. Connect the negative (-) test lead to the ground lug in
the transfer switch. Connect the positive (+) test lead to
Wire 15B at the terminal strip in the transfer switch.
a. If voltage is present repair or replace Wire 0
between transfer switch and generator ground
lug.
b. If voltage is not present proceed to Step 19.
19. Connect the negative (-) test lead to the ground lug in
the generator control panel. Connect the positive (+) test
lead to Wire 15B at the terminal strip in the generator
control panel.
a. If voltage is present, repair Wire 15B between
generator ter minal strip and transfer switch
terminal strip.
b. If voltage is not present, proceed to Step 20.
20. Remove the J2 connector from the circuit board.
21. Set VOM to measure ohms. Connect one meter test lead
to Wire 15B at the control panel terminal strip. Connect
the other meter test lead to Wire 15B Pin Location J2-8.
Continuity should be measured.
a. If continuity is not measured, repair pin connection
b. If continuity is measured proceed to Step 22.
and or Wire 15B between the J2 connector and
terminal strip.
22. Remove the 7.5A fuse.
23. Reconnect J2 connector.
24. Install the 7.5A fuse.
25. Disconnect Wire 15B from the generator terminal strip.
26. Set VOM to measure DC voltage.
caution: after installing the 7.5a fuse and dis-
connecting Wire 15B from the generator termi-
*
nal strip, wait 5 minutes before proceeding.
27. Connect one meter test lead to Wire 15B. Connect the other
meter test lead to Wire 0. 12 VDC should be measured.
a. If 12 VDC is not measured, replace the printed
circuit board.
b. If 12 VDC is measured, a short exists on Wire
15B or the transfer relay is shorted. Repair or
replace as needed.
teSt 29 – teSt tranSFer relay tr
DISCUSSION:
In automatic operating mode, the transfer relay must
be energized by circuit board action or standby source
power will not be available to the standby closing coil.
Without standby source power, the closing coil will
remain de-energized and transfer to “Standby” will not
occur. This test will determine if the transfer relay is
functioning normally.
Figure 3. Transfer Relay Test Points
PROCEDURE:
1. See Figure 3. Disconnect all wires from the transfer
relay, to prevent interaction.
2. Set a VOM to its “R x 1” scale and zero the meter.
3. Connect the VOM test leads across Relay Terminals 6
and 9 with the relay de-energized. The VOM should read
INFINITY.
CONNECT VOM TEST
LEADS ACROSS
Terminals 6 and 9 Continuity Infinity
Terminals 1 and 7 Infinity Continuity
DESIRED METER READING
ENERGIZED DE-ENERGIZED
Page 77
sEctioN 3.4
DiaGNostic tEsts
Part 3
TRANSFER SWITCH
4. Using jumper wires, connect the positive (+) post of a
12 volt battery to relay Terminal “A” and the negative
(-) battery post to Relay Terminal “B”. The relay should
energize and the VOM should read CONTINUITY.
5. Now, connect the VOM test leads across Relay Terminals
1 and 7.
a. Energize the relay and the meter should
indicate INFINITY.
b. De-energize the relay and the VOM should read
CONTINUITY.
RESULTS:
1. Replace transfer relay if it is defective.
2. If transfer relay checks good go to Test 31.
teSt 30 – StandBy control circuit
DISCUSSION:
Refer to Figure 4. The standby coil (C2) requires 240
VAC to energize. When the transfer relay is energized,
240 VAC is applied to standby coil C2. Once energized,
the coil will pull the transfer switch down to the standby
position. Once in the standby position, limit switch SW3
will open, removing AC to standby coil C2.
PROCEDURE/ RESULTS:
1. Set VOM to measure AC voltage.
2. Verify the transfer switch is up in the utility position.
3. Remove Wire E2 from standby coil C2.
a. If 240 VAC is not measured, replace transfer
relay.
b. If 240 VAC is measured, proceed to Step 9.
9. Measure across points A and F. 240 VAC should be
measured.
a. If 240 VAC is not measured, repair or replace
Wire 205.
b. If 240 VAC is measured, proceed to Step 10.
10. Measure across points A and G. 240 VAC should be
measured.
a. If 240 VAC is not measured, verify limit switch
SW3 is wired correctly. Proceed to Test 33.
b. If 240 VAC is measured, proceed to Step 11.
11. Measure across points A and H. 240 VAC should be
measured.
a. If 240 VAC is not measured, repair or replace
Wire B.
b. If 240VAC is measured, replace standby coil C2.
23 to initiate a transfer to standby. When Wire 23 is
grounded the transfer relay (TR1) is energized. To
initiate a transfer back to utility the TR1 relay must be
de-energized. If Wire 23 is grounded, TR1 will always
be energized.
4. Set the generator AUTO-OFF-MANUAL switch in the
AUTO position. Turn off the utility power supply to the
transfer switch, simulating a utility failure. The generator
should start and the transfer relay should energize.
5. Measure across points A and B. 240 VAC should be
measured.
a. If 240 VAC is not measured go back to Test 26.
b. If 240 VAC is measured, proceed to Step 6.
6. Measure across points C (Wire E2 previously removed)
and B. 240 VAC should be measured.
a. If 240 VAC is not measured, repair or replace
Wire E2.
b. If 240 VAC is measured, proceed to Step 7.
7. Measure across points A and D. 240 VAC should be
measured.
a. If 240 VAC is not measured, repair or replace
Wire E1.
b. If 240 VAC is measured, proceed to Step 8.
8. Measure across points A and E. 240 VAC should be
measured.
Page 78
PROCEDURE/ RESULTS:
1. Set VOM to measure DC voltage.
2. Set the generator AUTO-OFF-MANUAL switch in the
OFF position.
3. Connect the positive (+) meter test lead to Wire 15B
at the terminal strip in the transfer switch. Connect the
negative (-) meter test lead to Wire 23 at the terminal
strip in the transfer switch.
a. If 0 VDC is measured, proceed to Step 4.
b. If 12 VDC is measured, proceed to Step 6.
4. Set the generator AUTO-OFF-MANUAL switch in the
AUTO position.
5. Connect the positive (+) meter test lead to Wire 15B
at the terminal strip in the transfer switch. Connect the
negative (-) meter test lead to Wire 23 at the terminal
strip in the transfer switch
a. If 12 VDC is measured, procced to Step b.
b. Navigate to the Digital Output Display Screen
(see Figure 5).
(1) Press “ESC” until the main menu is reached.
TRANSFER SWITCH
A B
7 9
4 6
1 3
TR1
SW1
205
C2
SW3
E1
SW2
C1
12
12
N1N2
E1E2
E2
T1T2
B
A
G
E
F
C
D
H
Part 3
sEctioN 3.4
DiaGNostic tEsts
Figure 4. Standby Control Circuit Test Points
Page 79
DEBUG
OUTPUTS
OUTPUT 8
OUTPUTS 1 - 8:
1 0 1 1 0 0 0 1
GENERATOR
TERMINAL STRIP
CUSTOMER SIDE
N1/N2
CONTROL BOARD
CONNECTION
0
N1
N2
15B
23
sEctioN 3.4
DiaGNostic tEsts
(2) Press the right arrow key until “Debug” is
flashing.
(3) Press “Enter”.
(4) Press the right arrow key until “Outputs” is
flashing.
(5) Press “Enter”.
(6) Digital Output 8 is Wire 23 output from the
board. Refer to Figure 5.
(7) If Output 8 shows a “1” then the control
board is grounding Wire 23. Replace the
printed circuit board.
c. If 0 VDC is measured, the Wire 23 circuit is
good. Refer to flow chart.
Part 3
TRANSFER SWITCH
Figure 5. The Home Page, Debug and Output Screens
6. Locate the terminal strip in the generator control panel.
Disconnect Wire 23 coming in from the transfer switch
(customer connection, side-see Figure 6).
7. Connect the positive (+) meter test lead to Wire 15B at
the terminal strip in the generator. Connect the negative (-) meter test lead to Wire 23 just removed from
the terminal strip.
a. If 0 VDC is measured, proceed to Step 8.
b. If 12 VDC is measured, a short to ground exists
on Wire 23 between the generator and transfer
switch. Repair or replace Wire 23 as needed
between generator control panel and transfer
switch relay (TR1).
8. Locate the terminal strip in the generator control panel.
Disconnect Wire 23 coming in from the transfer switch
(customer connection, side - see Figure 6).
Page 80
Figure 6. Transfer Relay Test Points
9. Disconnect the J2 connector from the printed circuit board.
10. Set VOM to measure resistance.
11. Connect one meter test lead to Wire 23 connected at
generator terminal strip. See Figure 6. Connect the other
meter test lead to control panel ground.
a. If INFINITY or open is measured, replace the
printed circuit board
b. If continuity measured, Wire 23 is shorted to
ground. Repair or replace Wire 23 between the
J2 connector and the generator terminal strip.
23 to initiate a transfer to standby. When Wire 23 is
grounded the transfer relay (TR1) is energized. To
initiate a transfer back to utility the TR1 relay must be
de-energized. If Wire 23 is grounded, TR1 will always
be energized.
PROCEDURE/ RESULTS:
Refer to Figure 7.
1. Turn off utility supply voltage to the transfer switch.
2. Set VOM to measure AC voltage.
3. Set the generator AUTO-OFF-MANUAL switch in the
OFF position. Remove Wire 15B from the transfer switch
terminal strip.
4. Verify the transfer switch is down in the standby position.
TRANSFER SWITCH
N1A
N1A
A B
7 9
4 6
1 3
TR1
SW1
B
C2
SW3
SW2
C1
A
N2A
N2A
F1F2F3
AAA
BBB
12
12
N1N2
E1E2
T1T2
126
A
B
I
G
C
D
E
F
H
Part 3
sEctioN 3.4
DiaGNostic tEsts
Figure 7. Utility Control Circuit Test Points
Page 81
sEctioN 3.4
DiaGNostic tEsts
Part 3
TRANSFER SWITCH
5. Remove Wire N2A from the utility coil C1.
6. Turn on utility power supply to the transfer switch.
a. If transfer to utility occurs, Wire 23 is grounded.
Proceed to Test 31.
b. If transfer to utility does not occur, proceed to
Step 7.
7. Measure across points A and B. 240 VAC should be
measured.
a. If 240 VAC is not measured, verify utility source.
b. If 240 VAC is measured, proceed to Step 8.
8. Measure across points C (Wire N2A previously removed)
and B. 240 VAC should be measured.
a. If 240 VAC is not measured, repair or replace
Wire N2A.
b. If 240 VAC is measured, proceed to Step 9.
9. Measure across points A and D. 240 VAC should be
measured.
a. If 240 VAC is not measured, repair or replace
Wire N1A.
b. If 240 VAC is measured, proceed to Step 10.
10. Measure across points A and E. 240 VAC should be
measured.
a. If 240 VAC is not measured, repair or replace
Wire N1A.
b. If 240 VAC is measured, proceed to Step 11.
11. Measure across points A and F. 240 VAC should be
measured.
a. If 240 VAC is not measured, replace transfer
relay.
b. If 240 VAC is measured, proceed to Step 12.
12. Measure across points A and G. 240 VAC should be
measured.
a. If 240 VAC is not measured, repair or replace
Wire 126.
b. If 240 VAC is measured, proceed to Step 13.
13. Measure across points A and H. 240 VAC should be
measured.
a. If 240 VAC is not measured, verify limit switch
SW2 is wired correctly. Proceed to Test 33.
b. If 240 VAC is measured, proceed to Step 14.
14. Measure across points A and I. 240 VAC should be
measured.
a. If 240 VAC is not measured, repair or replace
Wire A.
b. If 240 VAC is measured, replace utility coil C1.
Coil nominal resistance is 1-2 megohms.
teSt 33 – teSt limit SWitch SW2 and SW3
DISCUSSION:
The limit switches are wired to the normally closed
contacts. When the switches are activated the
contacts open.
PROCEDURE:
With the generator shut down, the generator main
circuit breaker turned OFF, and with the utility power
supply to the transfer switch turned OFF, test limit
switch SW2/SW3 as follows:
1. To prevent interaction, disconnect Wire 126 and Wire A
from limit switch SW2 terminals.
2. Set a VOM to its “R x 1” scale and zero the meter.
3. See Figure 1. Connec t the VOM meter test lea ds
across the two outer terminals from which the wires
were disconnected.
4. Manually actuate the main contacts to their Standby
position. The meter should read CONTINUITY.
5. Manua lly actuate the main contacts to their Utility
position. The meter should read INFINITY.
6. Repeat Steps 4 and 5 several times and verify the VOM
reading at each switch position.
7. To prevent interaction, disconnect Wire 205 and Wire B
from limit switch SW3 terminals.
8. See Figure 1. Connec t the VOM meter test lea ds
across the two outer terminals from which the wires
were disconnected.
9. Manually actuate the main contacts to their Standby
position. The meter should read INFINITY.
10. Manually actua te the main contacts to their Utility
position. The meter should read CONTINUITY.
11. Repeat Steps 4 and 5 several times and verify the VOM
reading at each switch position.
RESULTS:
1. If Limit Switch SW2 or SW3 fails the test, remove and
replace the switch or adjust switch until it is actuated
properly.
teSt 34 – check FuSeS F1 and F2
DISCUSSION:
Fuses F1 and F2 are connected in series with the N1
and N2 circuits, respectively. A blown fuse will open
the applicable circuit and will result in (a) generator
startup and transfer to “Standby”, or (b) failure to
retransfer back to the utility source.
Page 82
BLACK
T1
N1AN2A
N1
N2
F1
F3
F2
TRANSFER SWITCH
Part 3
sEctioN 3.4
DiaGNostic tEsts
PROCEDURE:
1. On the generator panel, set the AUTO-OFF-MANUAL
switch to OFF.
2. Turn off the utility power supply to the transfer switch,
using whatever means provided.
3. Remove fuses F1 and F2 from the fuse holder (see
Figure 8).
4. Inspect and test fuses for blown condition. With a VOM
set to measure resistance, CONTINUITY should be
measured across the fuse.
6. Connect the positive meter test lead to Wire N1 at the
terminal block in the control panel.
a. Connect the negative meter lead to the ground
lug. INFINITY should be measured.
b. Connect the negative meter lead to Wire
23 at the terminal strip. INFINITY should be
measured.
c. Connect the negative meter lead to Wire 15B at
the terminal strip. INFINITY should be measured.
d. Connect the negative meter lead to Wire 0 at the
terminal strip. INFINITY should be measured.
e. Connect the negative meter lead to Wire N2 at the
terminal block. INFINITY should be measured.
f. Connect the negative meter lead to the neutral
connection. INFINITY should be measured.
7. Connect the positive meter test lead to Wire N2 at the
terminal block in the control panel.
a. Connect the negative meter lead to the ground
lug. INFINITY should be measured.
b. Connect the negative meter lead to Wire 23 at
the terminal strip. INFINITY should be measured.
c. Connect the negative meter lead to Wire 15B at
the terminal strip. INFINITY should be measured.
d. Connect the negative meter lead to Wire
0 at the terminal strip. INFINITY should be
measured.
e. Connect the negative meter lead to the neutral
connection. INFINITY should be measured.
Figure 8. Fuse Holder and Fuses
RESULTS:
1. Replace blown fuse(s) as needed.
teSt 35 – check n1 and n2 WirinG
DISCUSSION:
A shorted Wire N1 or N2 to ground can cause fuse F1
or F2 to blow.
PROCEDURE:
1. On the generator panel, set the AUTO-OFF-MANUAL
switch to OFF.
2. Turn off the utility power supply to the transfer switch,
using whatever means provided.
3. Remove fuses F1, F2, and F3 from the fuse holder (see
Figure 7).
4. Remove the generator control panel cover. Disconnect
the N1/N2 connector that supplies the printed circuit
board located in the control panel (see Figure 6).
5. Set VOM to measure resistance.
RESULTS:
If a short is indicated in Step 6 or Step 7, repair wiring
and re-test.
teSt 36 – check n1 and n2 VoltaGe
DISCUSSION:
Loss of utility source voltage to the generator will initi-
ate a startup and transfer by the generator. Testing at
the control panel terminal block will divide the system
in two, thereby reducing troubleshooting time.
PROCEDURE:
1. Set the AUTO-OFF-MANUAL switch to OFF.
2. Set a VOM to measure AC voltage.
3. See Figure 9. Connect one test lead to Wire N1 at the
terminal block in the generator control panel. Connect
the other test lead to Wire N2. Utility line-to-line voltage
should be measured.
RESULTS:
Refer to Flow Chart
Page 83
240 VAC
N1
N2
TEST POINTS
N2
N1
N1A N2A
F1F2F3
AAA
BBB
T1
sEctioN 3.4
DiaGNostic tEsts
Figure 9. Terminal Block Test Points
teSt 37 – check utility SenSinG
VoltaGe at the circuit Board
Part 3
PROCEDURE:
With utility source voltage available to terminal lugs
N1 and N2, use a VOM to test for utility source lineto-line voltage across terminal locations N1 and N2
terminals. Normal line-to-line utility source voltage
should be indicated.
TRANSFER SWITCH
DISCUSSION:
If the generator starts and transfer to STANDBY
occurs in the automatic mode when acceptable
UTILITY source voltage is available at the terminal
block, the next step is to determine if sensing voltage
is reaching the printed circuit board.
note: the System ready led will flash in auto or
utility loSt will display on the panel.
PROCEDURE:
1. Set the AUTO-OFF-MANUAL switch to OFF.
2. Disconnect the N1/N2 connector in the control panel
(see Figure 6).
3. Set a VOM to measure AC voltage.
4. Connect one meter test lead to Wire N1. Connect the
other meter test lead to Wire N2. Approximately 240
VAC should be measured. See Figure 9.
RESULTS:
1. If voltage was measured in Step 4 and the pin connections are good, replace the circuit board.
2. If voltage was NOT measured in Step 4, repair or replace
Wire N1/N2 between connector and terminal block.
teSt 38 – check utility SenSe VoltaGe
The N1 and N2 terminals in the transfer switch deliver
utility voltage “sensing” to a circuit board. If voltage at
the terminals is zero or low, standby generator startup
and transfer to the “Standby” source will occur automatically as controlled by the circuit board. A zero
or low voltage at these terminals will also prevent
retransfer back to the “Utility” source.
Page 84
Figure 10. Transfer Switch Fuse Block
RESULTS:
1. If voltage reading across the N1 and N2 terminals is
zero or low, refer to Flow Chart.
2. If voltage reading is good, refer to Flow Chart.
teSt 39 – check VoltaGe at terminal
luGS n1, n2
DISCUSSION:
If source voltage is not available to N1/N2 terminals,
automatic startup and transfer to STANDBY will occur
when the generator AUTO-OFF-MANUAL switch is
set to AUTO. This test will prove that “Utility” voltage is
available to those terminals, or is not available.
DaNGEr: ProcEED WitH cautioN! HiGH
*
PROCEDURE:
1. Make sure that all main line circuit breakers in the utility
aND DaNGErous VoltaGEs arE PrEsENt
at tErmiNal luGs N1/N2. coNtact WitH
HiGH VoltaGE tErmiNals Will rEsult
iN DaNGErous aND PossiBlY lEtHal
ElEctrical sHocK. Do Not attEmPt
tHis tEst WHilE staNDiNG oN WEt or
DamP GrouND, WHilE BarEfoot, or
WHilE HaNDs or fEEt arE WEt.
Figure 11. Test 40, 41, and 42 “Pre-Wire Load Center” Test Points.
Page 85
sEctioN 3.4
DiaGNostic tEsts
Part 3
TRANSFER SWITCH
2. Test for utility source line-to-line voltage across Terminal
Lugs N1 and N2 (see Figure 1). Normal utility source
voltage should be indicated.
RESULTS:
1. If low or no voltage is indicated, find the cause of the
problem and correct.
2. If normal utility source voltage is indicated, refer to
Flow Chart.
teSt 40 – check Battery charGer
Supply VoltaGe
“pre-Wire load center”
DISCUSSION:
The battery charger is supplied with 120 VAC. The
output of the battery charger is 13.4 VDC / 2.5A.
PROCEDURE:
Refer to Figure 11.
1. Set VOM to measure AC voltage.
2. Measure across points A and B. 240 VAC should be
measured.
a. If 240 VAC is not measured, verify load source
voltage.
b. If 240 VAC is measured go to Step 3.
3. Measure across points A and C. 240 VAC should be
measured.
a. If 240 VAC is not measured, repair or replace
Wire T1.
b. If 240VAC is measured, proceed to Step 4.
4. Measure across points A and D. 240 VAC should be
measured.
a. If 240 VAC is not measured, replace fuse F3.
b. If 240VAC is measured, proceed to Step 5.
5. Remove Fuse F3. Measure across points D and C.
120 VAC should be measured.
a. If 120 VAC is not measured, verify neutral wire
is connected at point E. If good, replace battery
charger, then retest.
b. If 120VAC is measured, refer to Flow Chart.
teSt 41 – check Battery charGer
output VoltaGe
“pre-Wire load center”
DISCUSSION:
The battery charger is supplied with 120VAC. The out-
put of the battery charger is 13.4 VDC / 2.5A.
Page 86
PROCEDURE:
Refer to Figure 11.
1. Set VOM to measure DC voltage.
2. Remove Wire 0 and Wire 15B from transfer switch
terminal strip points F and G.
3. Measure across points H and I. Battery supply voltage
(12 VDC) should be measured.
a. If battery voltage is not measured, wait 5 minutes
and repeat Step 3.
b. If battery supply voltage is still not available,
refer to Flow Chart.
c. If battery voltage is measured, proceed to Step 4.
4. Reconnect Wire 0 and Wire 15B previously removed
in Step 2.
5. Measure across points H and I. 13.4 VDC should
be measured.
a. If 13.4 VDC is not measured, replace the
battery charger
b. If 13.4 VDC is measured, the charger is working.
*note: Battery charger voltage will be higher than
battery supply voltage.
teSt 42 – check Wire 0 and Wire15B
“pre-Wire load center”
DISCUSSION:
In order for the battery charger to function, battery supply
voltage must be available to the battery charger.
PROCEDURE:
Refer to Figure 11.
1. Set VOM to measure DC voltage.
2. Disconnect Wire 0 and Wire 15B from generator terminal
strips, locations J and K.
3. Wait five (5) minutes after removing wires.
4. Measure across points L and M on the terminal strip.
12 VDC should be measured.
a. If 12 VDC is measured, proceed to Step 6.
b. If 12 VDC is not measured, proceed to Step 5.
5. Measure across points M and N. 12 VDC should be
measured.
a. If 12 VDC is measured, repair or replace Wire
0 between the generator terminal strip and the
ground lug.
b. If 12 VDC is not measured, proceed to Step 8.
6. Set VOM to measure resistance.
7. Connect the meter test leads across the disconnected
Wire 0 and Wire 15B. Approximately 115 Ohms should
be measured.
TRANSFER SWITCH
Part 3
sEctioN 3.4
DiaGNostic tEsts
a. If 115 Ohms is measured, proceed to Step 10.
b. If zero resistance or CONTINUITY is measured,
connect the meter test leads across Terminals
A and B on the transfer relay (TR1)
c. If zero resistance is measured, a short exists.
Replace TR1.
d. If 115 Ohms is measured, repair or replace
Wire 15B between the generator and the
transfer switch.
8. Set VOM to measure resistance.
9. Disconnect the J2 connector from the printed circuit board.
10. Measure across point M and pin location J2-8 of the connector just removed. Continuity should be measured.
a. If continuity is not measured, repair or replace
Wire 15B between the J2 connector and the
terminal strip.
b. If continuity is measured and the pin connection
looks good, the internal fuse on the PCB has
failed. Replace printed circuit board.
teSt 43 – check Battery charGer
Supply VoltaGe
“rtSn & rtSe tranSFer SWitch”
DISCUSSION:
The battery charger is supplied with 120 VAC. The
output of the battery charger is 13.4 VDC/2.5A.
PROCEDURE:
Refer to Figure 12 or Figure 12A.
1. Set VOM to measure AC voltage.
2. Measure across points A and B. 240 VAC should be
measured.
a. If 240 VAC is not measured, verify load source
voltage.
b. If 240 VAC is measured, proceed to Step 3.
3. Measure across points A and C. 240 VAC should be
measured.
a. If 240 VAC is not measured, repair or replace
wire between fuse block and T1 terminal.
b. If 240VAC is measured, proceed to Step 4.
4. Measure across points A and D. 240 VAC should be
measured.
a. If 240 VAC is not measured, replace 5A fuse.
b. If 240 VAC is measured, proceed to Step 5.
5. Measure across points E and F. 120 VAC should be
measured.
a. If 120 VAC is not measured, repair or replace
supply wires BC line and BC 00.
b. If 120 VAC is measured, refer to flow chart.
teSt 44 – check Battery charGer
output VoltaGe
“rtSn & rtSe tranSFer SWitch”
DISCUSSION:
The battery charger is supplied with 120 VAC. The
output of the battery charger is 13.4 VDC/2.5A.
PROCEDURE:
Refer to Figure 12 or Figure 12A.
1. Set VOM to measure DC voltage.
2. Remove and isolate battery charger black and red leads
from generator terminal strip points G and H.
3. Measure across points G and H. Battery supply voltage
(12 VDC) should be measured.
a. If battery voltage is not measured, wait 5 minutes
and repeat Step 3. If battery supply voltage is still
not available, refer to Flow Chart.
b. If battery voltage is measured, proceed to Step 4.
4. Reconnect battery charger black and red lead wires
previously removed in Step 2.
5. Measure across points G and H. 13.4 VDC should be
measured.
a. If 13.4 VDC is not measured, replace the
battery charger
b. If 13.4 VDC is measured, the charger is working.
*note : Battery charger voltage will be higher
than battery supply voltage.
teSt 45 – check Wire 0/15B
“rtSn & rtSe tranSFer SWitch”
DISCUSSION:
In order for the battery charger to function, battery supply
voltage must be available to the battery charger.
PROCEDURE:
Refer to Figure 12 or Figure 12A.
1. Set VOM to measure DC voltage.
2. Remove and isolate battery charger black and red leads
from generator terminal strip points G and H.
3. Measure across points G and H on the terminal strip.
12VDC should be measured.
a. If 12 VDC is measured, the charger should be
functioning.
b. If 12 VDC is not measured, proceed to Step 4.
4. Remove Wire 0 and Wire 15B from generator terminal
strip locations G and H.
5. Wait five (5) minutes after removing wires.
Page 87
E2
WHITE
GREEN
23
15B
0
N1
DETAIL
DETAIL
N2
BC 00
BC LINE
E1
N2
N1
15B
23
N1
N2
23
194
UTILITY SUPPLY FROM
SERVICE DISCONNECT
E2
TO GROUNDING
ELECTRODE
NEUTRAL BLOCK
(DISTRIBUTION PANEL)
GROUND
BC LINE
BC 00
5 AMP
FUSE
T1T2
CUSTOMER LOAD
RTS TRANSFER SWITCH
T1T2
E1
(C2 & VR2)
STANDBY
E1E2
(C1 & VR1)
UTILITY
N1N2
N2
N1
C
D
E
A
B
H
G
F
23
15B
0
N1
N2
H
G
sEctioN 3.4
DiaGNostic tEsts
Part 3
TRANSFER SWITCH
Page 88
Figure 12. Test 43, 44, and 45 “RTSN Transfer Switch” Test Points.
TRANSFER SWITCH
WHITE
GREEN
0
N1
N2
15B
23
BC 00
BC LINE
TO GROUNDING
ELECTRODE
SERVICE DISCONNECT ATS
23
E1
E2
BC LINE
BC 00
FUSE
N2
N1
5 AMP
SOCKET
METER
UTILITY
PANELBOARD
15B
T1 T2
E1E2
N2N1
C
D
E
A
B
H
G
F
DETAIL
DETAIL
23
15B
0
N1
N2
H
G
Part 3
sEctioN 3.4
DiaGNostic tEsts
Figure 12A. Test 43, 44, and 45 “RTSE Transfer Switch” Test Points.
Page 89
sEctioN 3.4
DiaGNostic tEsts
Part 3
TRANSFER SWITCH
6. Measure across points G and H on the terminal strip.
12 VDC should be measured.
a. If 12 VDC is measured, proceed to Step 8.
b. If 12 VDC is not measured, proceed to Step 7.
7. Measure across point H and ground lug. 12 VDC should
be measured.
a. If 12 VDC is measured, repair or replace Wire
0 between the generator terminal strip and the
ground lug.
b. If 12 VDC is not measured, proceed to Step 8.
8. Set VOM to measure resistance.
9. Connect the meter test leads across the disconnected
Wire 0 and Wire 15B. Approximately 115 Ohms should
be measured.
a. If 115 Ohms is measured, proceed to Step 11.
b. If zero resistance or CONTINUITY is measured,
connect the meter test leads across Terminals
A and B on the transfer relay (TR1)
c. If zero resistance is measured, a short exists.
Replace TR1.
d. If 115 Ohms is measured, repair or replace
Wire 15B between the generator and the
transfer switch.
10. Disconnect the J2 connector from the printed circuit
board.
11. Measure across point M and pin location J2-8 of the connector just removed. CONTINUITY should be measured.
a. If CONTINUITY is not measured, repair or
replace Wire 15B between the J2 connector
and the terminal strip.
b. If CONTINUITY was measured and the pin con-
nection looks good, the internal fuse on the PCB
has failed. Replace the printed circuit board.
teSt 46 – check Battery charGer
Supply VoltaGe
“Genready load center”
b. If 120 VAC is measured, proceed to Step 3.
3. Measure across points C and D. 120 VAC
should be measured.
a. If 120 VAC is not measured, repair or replace
Wire BC LINE or BC 00 between the load center and the generator.
b. If 120 VAC is measured, refer to Flow Chart.
teSt 47 – check Battery charGer
output VoltaGe
“Genready load center”
DISCUSSION:
The battery charger is supplied with 120VAC. The
output of the battery charger is 13.4 VDC / 2.5A.
PROCEDURE:
Refer to Figure 13.
1. Set VOM to measure DC voltage.
2. Remove and isolate battery charger black and red leads
from generator terminal strip points E and F.
3. Measure across points E and F. Battery supply voltage
(12 VDC) should be measured.
a. If battery voltage is not measured, wait 5 min-
utes and repeat Step 3. If battery supply voltage
is still not available, refer to Flow Chart.
b. If battery voltage is measured, proceed to Step 4.
4. Reconnect battery charger black and red lead wires
previously removed in Step 2.
5. Measure across points E and F. 13.4 VDC should be
measured.
a. If 13.4 VDC is not measured, replace the
battery charger.
b. If 13.4 VDC is measured, the charger is working.
*note: Battery charger voltage will be higher than
battery supply voltage.
DISCUSSION:
The battery charger is supplied with 120VAC. The
output of the battery charger is 13.4 VDC / 2.5A.
PROCEDURE:
Refer to Figure 13.
1. Set VOM to measure AC voltage.
2. Measure across points A and B. 120 VAC should be
measured.
a. If 120 VAC is not measured, verify that load
source voltage is available, and that the duplex
circuit breaker in ON.
Page 90
teSt 48 – check Wire 0/15B
“Genready load center”
DISCUSSION:
In order for the battery charger to function, battery supply
voltage must be available to the battery charger.
PROCEDURE:
Refer to Figure 13.
1. Set VOM to measure DC voltage.
2. Remove and isolate battery charger black and red leads
from generator terminal strip points E and F.
TRANSFER SWITCH
CONNECTION PANEL
BC-LINE
GEN-READY
LOAD CENTER
DUPLEX BREAKER
BC-00
UTILITY
SOCKET
METER
ENGINE GENERATOR
N1
WHITE
GREEN
BC 00
N2
15B
23
0
E1
E2
BC LINE
C
D
E
A
B
F
DETAIL
DETAIL
DETAIL
DETAIL
BC 00
BC LINE
N1
N2
15B
23
0
E
F
C
D
Part 3
sEctioN 3.4
DiaGNostic tEsts
Figure 13. Test 46, 47, and 48 “GenReady Load Center” Test Points.
Page 91
sEctioN 3.4
DiaGNostic tEsts
Part 3
TRANSFER SWITCH
3. Measure across points G and H on the terminal strip.
12VDC should be measured.
a. If 12 VDC is measured, the charger should be
functioning.
b. If 12 VDC is not measured, proceed to Step 4.
4. Remove Wire 0 and Wire 15B from generator terminal
strip locations E and F.
5. Wait five (5) minutes after removing wires.
6. Measure across points E and F on the terminal strip.
12 VDC should be measured.
a. If 12 VDC is measured, proceed to Step 8.
b. If 12 VDC is not measured, proceed to Step 7.
7. Measure across point H and ground lug. 12 VDC should
be measured.
a. If 12 VDC is measured, repair or replace Wire
0 between the generator terminal strip and the
ground lug.
b. If 12 VDC is not measured, proceed to Step 8.
8. Set VOM to measure resistance.
9. Connect the meter test leads across the disconnected
Wire 0 and Wire 15B. Approximately 200 Ohms should
be measured.
a. If 200 Ohms is measured, proceed to Step 11.
b. If zero resistance or CONTINUITY is measured,
connect the meter test leads across BAT- and
XFER on the load center motor.
c. If zero resistance is measured, a short exists.
Replace the load center motor.
d. If 200 Ohms to INFINITY is measured, repair
or replace Wire 15B between the generator and
the load center.
10. Disconnect the J2 connector from the printed circuit board.
11. Measure across point M and pin location J2-8 of the
connector just removed. CONTINUITY should be
measured.
a. If CONTINUITY is not measured, repair or
replace Wire 15B between the J2 connector
and the terminal strip.
b. If CONTINUITY is measured and the pin con-
nection looks good, the internal fuse on the PCB
has failed. Replace the printed circuit board.
PROCEDURE:
Refer to Figure 14.
1. Set VOM to measure AC voltage.
2. Measure across points A and B. 240 VAC should be
measured.
a. If 240 VAC is not measured, verify load source
voltage at ATS.
b. If 240 VAC is measured, proceed to Step 3.
3. Measure across points A and C. 240 VAC should be
measured.
a. If 240 VAC is not measured, repair or replace
Wire T1 between LSS and J3 terminal of load
shed controller.
b. If 240VAC is measured, proceed to Step 4.
4. Measure across points C and D. 120 VAC should be
measured.
a. If 120 VAC is not measured, repair or replace
Wire 00 between J3 terminal and neutral block
(NB).
b. If 120 VAC is measured, proceed to Step 5.
5. Measure across points E and D. 120 VAC should be
measured.
a. If 120 VAC is not measured, replace fuse F3 on
load shed controller.
b. If 120 VAC is measured, proceed to Step 6.
6. Measure across points E and F. 120 VAC should be
measured.
a. If 120 VAC is not measured, replace load shed
controller.
b. If 120 VAC is measured, refer to Flow Chart.
teSt 50 – check Battery charGer
output VoltaGe
“load Shed tranSFer SWitch”
DISCUSSION:
The battery charger is supplied with 120 VAC. The
output of the battery charger is 13.4 VDC/2.5A.
PROCEDURE:
Refer to Figure 14.
1. Set VOM to measure DC voltage.
teSt 49 – check Battery charGer
Supply VoltaGe
“load Shed tranSFer SWitch”
DISCUSSION:
The battery charger is supplied with 120 VAC. The
output of the battery charger is 13.4 VDC/2.5A.
Page 92
2. Remove and isolate battery charger black and red leads
from generator terminal strip points G and H.
3. Measure across points G and H. Battery supply voltage
(12 VDC) should be measured.
a. If battery voltage is not measured, wait 5 min-
utes and repeat Step 3. If battery supply voltage
is still not available, refer to Flow Chart.
b. If battery voltage is measured, proceed to Step 4.
TRANSFER SWITCH
FUSE, 2AF3
GROUND LUG
LIMIT SWITCHES, ACTUATOR
RELAY, TRANSFER
UTILITY CIRCUIT BREAKER
NB - NEUTRAL BLOCK
LOAD SHED CONTROLLER
RELAY, LOAD SHED
LOAD SHED TRANSFER SWITCH CONTACTOR
XA1,XB1
TR
UCB
GNDLSLSC
LSS
NB
SOLENOID COIL (LSS-OFF)
SOLENOID COIL (LSS-ON)
FUSE, 5A
TRANSFER SWITCH CONTACTOR
SOLENOID COIL (UTILITY CLOSING)
SOLENOID COIL (STANDBY CLOSING)
BATTERY CHARGER
F1,F2
C1
C1A
C2A
C2
ATS
BC
LEGEND
(C2A)
T2T1
XB1
XA1
(C1A)
LSS
E2E1
N2N1
(C2)
T1T2
ATS
XB1
E1
(C1)
XA1
N1
E2
N2
NB
WHT
CONNECTION
CUSTOMER
0
15B
23
S1
321
J6
1 2
J5
LSC
OUTPUT
RED
BLK
BC
656544
TR
D2
87
A
9
B
D1
LS
7
A
98
B
213
1432
132
F3
J4
6 75
CONTROLLER
LOAD SHED
1
J1
J3
00
INPUT
WHT
BLK
BLK
NON-ESSENTIAL
LOAD CONNECTION
OUTPUT CONNECTION
GENERATOR
T1
T2
E1A
AA
BB
1 2 3546
C
D
E
A
B
H
G
I
K
J
F
Part 3
sEctioN 3.4
DiaGNostic tEsts
Figure 14. Test 49, 50, and 51 “Load Shed Transfer Switch” Test Points.
Page 93
sEctioN 3.4
DiaGNostic tEsts
Part 3
TRANSFER SWITCH
4. Reconnect battery charger black and red lead wires
previously removed in Step 2.
5. Measure across points G and H. 13.4 VDC should be
measured.
a. If 13.4 VDC is not measured, replace the
battery charger.
b. If 13.4 VDC is measured, the charger is working.
*note: Battery charger voltage will be higher than
battery supply voltage.
teSt 51 – check Wire 0 and Wire 15B
“load Shed tranSFer SWitch”
DISCUSSION:
In order for the battery charger to function, battery supply
voltage must be available to the battery charger.
PROCEDURE:
Refer to Figure 14.
1. Set VOM to measure DC voltage.
2. Remove and isolate battery charger black and red leads
from terminal strip points G and H.
3. Measure across points I and J on the terminal strip. 12
VDC should be measured.
a. If 12 VDC is measured, the charger should be
functioning.
b. If 12 VDC is not measured, proceed to Step 4.
4. Remove Wire 0 and Wire 15B from generator terminal
strip. Refer to Figure 6.
5. Wait five (5) minutes after removing wires.
6. Measure across points J and K on the terminal strip.
Refer to Figure 6. 12 VDC should be measured.
a. If 12 VDC is measured, proceed to Step 8.
b. If 12 VDC is not measured, proceed to Step 7.
7. In the generator control panel, measure across Wire 15B
and Wire 0 at the customer connection. 12 VDC should
be measured.
a. If 12 VDC is measured, repair or replace Wire
0 or Wire 15B between the generator terminal
strip and the ground lug.
b. If 12 VDC is not measured, proceed to Step 5.
8. Set VOM to measure resistance.
9. Connect the meter test leads across the disconnected
Wire 0 and Wire 15B. Approximately 115 Ohms should
be measured.
a. If 115 Ohms is measured, proceed to Step 11.
b. If zero resistance or CONTINUITY is measured,
connect the meter test leads across locations J
and k on the load shed controller, Figure 12.
c. If zero resistance is measured, a short exists.
Replace the transfer relay (TR).
d. If 200 115 is measured, repair or replace Wire
15B between the generator and the transfer
switch.
10. Disconnect the J2 connector from the printed circuit
board.
11. In the generator control panel, measure across Wire
15B at the customer connection and pin location J2-8
of the connector just removed. CONTINUITY should be
measured.
a. If CONTINUITY is not measured, repair or
replace Wire 15B between the J2 connector
and the terminal strip.
b. If CONTINUITY is measured, proceed to Step 12.
12. In the generator control panel, measure across Wire
0 at the customer connection and the ground lug.
CONTINUITY should be measured.
a. If CONTINUITY is not measured, repair or
replace Wire 0 between the customer connection
and the ground lug.
b. If CONTINUITY is measured and the pin con-
nection of J2 looks good, the internal fuse on the
PCB has failed. Replace the printed circuit board.
Page 94
Part 4
Dc coNtrol
air-cooled, automatic
standby Generators
taBlE of coNtENts
ParttitlEPaGE#
4.1.Description and components76
4.2operational analysis82
4.3troubleshooting flow charts96
4.4Diagnostic tests103
4.1 Description and Components ....................................96
General ...................................................................96
This section will familiarize the reader with the various
components that make up the DC control system.
Major DC control system components that will be
covered include the following:
• ATerminalStrip/InterconnectionTerminal
• ACircuitBoard.
• AnAUTO-OFF-MANUALSwitch.
• A7.5AmpFuse.
terminal Strip / interconnection
terminal
The terminals of this terminal strip are connected to
identically numbered terminals on a transfer switch
terminal board. The terminal board connects the
transfer switch to the circuit board.
The terminal board provides the following connection
points:
A. UTILITY 1 and UTILITY 2
1. Connect to identically marked terminals on a
transfer switch terminal board.
B. 23 and 15B
1. Connect to identically numbered terminals on
the terminal board of the transfer switch.
2. This circuit connects the circuit board to the
transfer relay coil in the transfer switch.
circuit Board
The circuit board controls all standby electric system
operations including (a) engine startup, (b) engine
running, (c) automatic transfer, (d) automatic retransfer, and (e) engine shutdown. In addition, the circuit
board performs the following functions:
low oil pressure, high oil temperature, overspeed,
no RPM sense, overcrank, or low battery.
An 18-pin and a 4-pin connector are used to interconnect the circuit board with the various circuits of
the DC systems. Connector pin numbers, associated
wires and circuit functions are listed in the CHART on
the next page.
If the Utility sensing voltage drops below a preset
value, circuit board action will initiate automatic
generator star tup and transfer to the “Standby”
source side.
The crank relay and fuel solenoid valve are energized
by circuit board action at the same time.
DIGITAL INPUT/OUTPUT FUNCTIONS:
PostionDigital inputsDigital outputs
1Low Oil PressureNot Used
2High TemperatureNot Used
3Internal UseNot Used
4Internal UseNot Used
5Internal UseFuel
6Not UsedStarter
7AutoIgnition
8ManualTransfer
Page 96
DaNGEr: tHE GENErator ENGiNE Will
craNK aND start WHEN tHE 7-DaY
*
EXErcisEr sWitcH is actuatED. tHE uNit
Will also craNK aND start EVErY 7
DaYs tHErEaftEr, oN tHE DaY aND at tHE
timE of DaY tHE sWitcH Was actuatED.
auto-oFF-manual SWitch
This 3-position switch permits the operator to (a)
select fully automatic operation, (b) start the generator
Figure 1. Terminal Strip
manually, or (c) stop the engine and prevent automatic
startup. Switch terminals are shown pictorially and
schematically in Figure 6, below.
DIVIDER PANEL
DIVIDER PANEL
TO ENGINE
TO ENGINE
6
7
9
8
3
5
4
1
2
10
1. CONTROL PANEL
2. 7.5 AMP FUSE
3. STARTER CONTACTOR RELAY
(10-20 KW)
4. 4 POSITION TERMINAL BLOCK
5. TERMINAL BLOCK
6. CIRCUIT BREAKER (8KW)
7. 15 AMP GFCI DUPLEX OUTLET
(17 & 20 KW)
8. CIRCUIT BREAKER (17 & 20 KW)
9. CIRCUIT BREAKER (10-20 KW)
10. LED DISPLAY
DC CONTROL
Part 4
7.5 amp FuSe
This fuse protects the circuit board against excessive
current. If the fuse has blown, engine cranking and
operation will not be possible. Should fuse replacement become necessary, use only an identical 7.5
amp replacement fuse.
sEctioN 4.1
DEscriPtioN aND comPoNENts
Figure 2. A Typical 7.5 Amp Fuse
Figure 3. Control Panel Component Identification
Page 97
J2J1
J2 CONNECTOR
(HARNESS END)
N1/N2 CONNECTOR
(HARNESS END)
N1/N2 CONNECTOR
(PCB END)
10 11 12 13 14 15 16 17 18
12
34
123456789
101112131415161718
12
34
123456789
101112131415161718
12
34
12
3456789
J1 CONNECTOR
(HARNESS END)
J2 CONNECTOR
(PCB END)
J1 CONNECTOR
(PCB END)
12
sEctioN 4.1
DEscriPtioN aND comPoNENts
Part 4
DC CONTROL
PiNWirEcircuit fuNctioN
J1-185High temperature shutdown:
J1-286Low oil pressure shutdown: Shutdown
J1-31312 VDC source voltage for the circuit
J1-418Ignition Shutdown: Circuit board
J2-10INTERNAL USE
J2-20INTERNAL USE
J2-31412 VDC output for engine run condi-
J2-523Switched to ground for transfer relay
J2-6NOT USED
Shutdown occurs when Wire 85 is
grounded by contact closure in HTO
occurs when Wire 86 is grounded by
loss of oil pressure to the LOP
Figure 4. 8 kW Printed Circuit Boards and J1 Connector
8 kW J1 connector Pin Descriptions
board
action grounds Wire 18 for ignition
shutdown.
tion. Used for fuel solenoid.
operation
PiNWirEcircuit fuNctioN
J2-7NOT USED
J2-815BProvides an electrical connection for
J2-9NOT USED
J2-100Common Ground
J2-115612 VDC output to starter contactor for
J2-15NOT USED
J2-16NOT USED
J2-17NOT USED
J2-18NOT USED
Wired Plug 1N1240 VAC sensing for control board.
Wired Plug 2N2240 VAC sensing for control board.
charge current to reach the battery
from the battery charger. Provides
12VDC to the Transfer Relay
single cylinder engines.
Page 98
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