AUTOMATIC HOME STANDBY GENERATORS
DIAGNOSTIC REPAIR MANUAL
AIR-COOLED
Models
Air-cooled, Prepackaged Automatic Standby Generators
DIAGNOSTIC REPAIR MANUAL
TABLE OF CONTENTS
Models 04389, 04758 6 kW NG, 7 kW LP
ELECTRICAL FORMULAS
STATOR WINDING RESISTANCE VALUES / ROTOR RESISTANCE
ENGINE
FUEL CONSUMPTION
SPECIFICATIONS
SPECIFICATIONS
MOUNTING DIMENSIONS
SPECIFICATIONS
MOUNTING DIMENSIONS
7 kW, Single Cylinder GH-410 Engine
MAJOR FEATURES
SPECIFICATIONS
12 kW and 15 kW, V-twin GT-990 Engine
Air-cooled, Prepackaged Automatic Standby Generators
TABLE OF CONTENTS
PART GENERAL INFORMATION
Models 04389, 04758 6 kW NG, 7 kW LP
PART
SECTION
GENERATOR IDENTIFICATION
INTRODUCTION
SELECTING A LOCATION
PREPACKAGED INSTALLATION BASICS
THE TRANSFER SWITCH / LOAD CENTER
GROUNDING THE GENERATOR
SECTION
PREPACKAGED INSTALLATION BASICS
Figure 1. Typical Prepackaged Installation
PART
PREPACKAGED INSTALLATION BASICS
POWER SOURCE AND LOAD LINES
SYSTEM CONTROL INTERCONNECTIONS
Figure 2. Proper Fuel Installation
FUEL REQUIREMENTS
PREPARATION BEFORE USE
GENERAL
SECTION
METERS
TESTING, CLEANING AND DRYING
VISUAL INSPECTION
THE VOM
MEASURING RESISTANCE
MEASURING AC FREQUENCY
MEASURING CURRENT
TESTING, CLEANING AND DRYING
TESTING, CLEANING AND DRYING
ELECTRICAL UNITS
OHMS LAW
SECTION
INSULATION RESISTANCE
TESTING, CLEANING AND DRYING
SECTION
THE MEGOHMMETER
3. Repeat Step 1 at Pin Location 7 Wire 6. and Stator Lead
TESTING, CLEANING AND DRYING
2. Repeat Step 1 at Pin Location 3 Wire 66A and Stator Lead
Figure 3. C2 Connector Pin Location Numbers Female Side
DRYING THE GENERATOR
CLEANING THE GENERATOR
ROTOR INSULATION RESISTANCE TEST
TESTING, CLEANING AND DRYING
SECTION
ENGINE-GENERATOR PROTECTIVE DEVICES
Figure 1. Engine Protective Switches on an Air-Cooled Engine
PART
SECTION
OPERATING INSTRUCTIONS
CONTROL PANEL
PART
MANUAL TRANSFER TO STANDBY AND MANUAL STARTUP
OPERATING INSTRUCTIONS
TO SELECT AUTOMATIC OPERATION
SECTION
OPERATING INSTRUCTIONS
MANUAL SHUTDOWN AND RETRANSFER BACK TO UTILITY
SECTION
PART
SECTION
AUTOMATIC OPERATING PARAMETERS
AUTOMATIC OPERATING SEQUENCES
PART
SECTION
AUTOMATIC OPERATING SEQUENCES CHART
AUTOMATIC OPERATING PARAMETERS
PART
2.3 Troubleshooting Flow Charts 2.4 Diagnostic Tests
PART AC GENERATORS
TABLE OF CONTENTS
Air-cooled, Prepackaged Automatic Standby Generators
THE AC GENERATOR
ROTOR ASSEMBLY
DESCRIPTION & COMPONENTS
ENGINE-GENERATOR DRIVE SYSTEM
BRUSH HOLDER AND BRUSHES
STATOR ASSEMBLY
DESCRIPTION & COMPONENTS
OTHER AC GENERATOR COMPONENTS
PART
SECTION
DESCRIPTION & COMPONENTS
Figure 5. Excitation Circuit Breaker
FIELD BOOST
OPERATIONAL ANALYSIS
ROTOR RESIDUAL MAGNETISM
Figure 2. Field Boost Circuit Schematic
OPERATIONAL ANALYSIS
OPERATION
SECTION
PART
SECTION
TROUBLESHOOTING FLOWCHARTS
Use the Flow Charts in conjunction with the detailed instructions in Section 2.4. Test numbers used in the flow charts correspond to the numbered tests in Section
PART
PART
TROUBLESHOOTING FLOWCHARTS
SECTION
AC GENERATORS
PART
TROUBLESHOOTING FLOWCHARTS
SECTION
AC GENERATORS
PART
TROUBLESHOOTING FLOWCHARTS
SECTION
AC GENERATORS
TEST 1- CHECK MAIN CIRCUIT BREAKER
DIAGNOSTIC TESTS
SAFETY
SECTION
DIAGNOSTIC TESTS
TEST 2- CHECK AC OUTPUT VOLTAGE
TEST 3- TEST EXCITATION CIRCUIT BREAKER
SECTION
SECTION
TEST 4- FIXED EXCITATION TEST ROTOR AMP DRAW TEST
DIAGNOSTIC TESTS
PART
DIAGNOSTIC TESTS
TEST 5 WIRE CONTINUITY
TEST 6 - CHECK FIELD BOOST
SECTION
SECTION
TEST 7 TESTING THE STATOR WITH A VOM
DIAGNOSTIC TESTS
PART
SECTION
TEST 8 - RESISTANCE CHECK OF ROTOR CIRCUIT
DIAGNOSTIC TESTS
PART
SECTION
TEST 9 - CHECK BRUSHES AND SLIP RINGS
DIAGNOSTIC TESTS
PART
TEST 11 - CHECK AC OUTPUT FREQUENCY
TEST 10 - TEST ROTOR ASSEMBLY
TEST 12 - CHECK AND ADJUST ENGINE GOVERNOR
DIAGNOSTIC TESTS
Figure 10. Engine Governor Adjustment V-twin Engines
DIAGNOSTIC TESTS
Figure 9. Engine Governor Adjustment Single Cylinder Engines
Figure 11. Full Load Speed Adjust ScrewV-twin Engines
TEST 14 - CHECK VOLTAGE AND FREQUENCY UNDER LOAD
TEST 13 - CHECK AND ADJUST VOLTAGE REGULATOR
TEST 15 - CHECK FOR OVERLOAD CONDITION
TEST 16 - CHECK ENGINE CONDITION
Air-cooled, Prepackaged Automatic Standby Generators
PART V-TYPE PREPACKAGED TRANSFER SWITCHES
TABLE OF CONTENTS
Models 04389, 04758 6 kW NG, 7 kW LP
DESCRIPTION & COMPONENTS
Figure 1. Exploded View of V-Type Prepackaged Transfer Switch
SECTION
PART
Figure 3. Load Connected to Standby Power Source
TRANSFER MECHANISM
Figure 2. Load Connected to Utility Power Source
SECTION
MANUAL TRANSFER HANDLE
TRANSFER RELAY
NEUTRAL LUG
TERMINAL BLOCK
SECTION
FUSE HOLDER
Figure 6. Transfer Switch Terminal Block
PART
V-TYPE PREPACKAGED TRANSFER SWITCHES
OPERATIONAL ANALYSIS
Figure 1. Wiring Diagram and Schematic
SECTION
SECTION
UTILITY SOURCE VOLTAGE AVAILABLE
Figure 2. Utility Source Power Available
PART
Figure 3. Generator Power Available, Waiting to Transfer
OPERATIONAL ANALYSIS
UTILITY SOURCE VOLTAGE FAILURE
SECTION
PART
TRANSFER TO STANDBY
SECTION
OPERATIONAL ANALYSIS
OPERATIONAL ANALYSIS
Figure 5. Generator Powering Load
SECTION
PART
V-TYPE PREPACKAGED TRANSFER SWITCHES
UTILITY RESTORED
Figure 6. Utility Restored, Generator Still Providing Output to Load
SECTION
SECTION
UTILITY RESTORED, TRANSFER SWITCH DE-ENERGIZED
Figure 7. Utility Restored, Transfer Relay De-energized
PART
SECTION
UTILITY RESTORED, RETRANSFER BACK TO UTILITY
Figure 8. Utility Restored, Retransfer Back to Utility
PART
V-TYPE PREPACKAGED TRANSFER SWITCHES
TRANSFER SWITCH IN UTILITY
Figure 9. Transfer Switch in UTILITY
SECTION
SECTION
TROUBLESHOOTING FLOW CHARTS
INTRODUCTION TO TROUBLESHOOTING
PART
SECTION
TROUBLESHOOTING FLOW CHARTS
V-TYPE PREPACKAGED TRANSFER SWITCHES
PART
SECTION
TEST 21- CHECK VOLTAGE AT TERMINAL LUGS E1, E2
DIAGNOSTIC TESTS
PART
SECTION
TEST 22 - CHECK VOLTAGE AT STANDBY CLOSING COIL C2
DIAGNOSTIC TESTS
PART
DIAGNOSTIC TESTS
TEST 24- CHECK MANUAL TRANSFER SWITCH OPERATION
TEST 23 - TEST TRANSFER RELAY TR
SECTION
SECTION
TEST 25- TEST LIMIT SWITCH XB1
DIAGNOSTIC TESTS
PART
DIAGNOSTIC TESTS
TEST 26 - CHECK 23 AND WIRING/CONNECTIONS
TEST 27- CHECK VOLTAGE AT TERMINAL LUGS N1, N2
SECTION
TEST 28 - CHECK VOLTAGE AT UTILITY 1 AND
UTILITY 2 TERMINALS
TEST 29- CHECK VOLTAGE AT UTILITY CLOSING COIL C1
DIAGNOSTIC TESTS
DIAGNOSTIC TESTS
TEST 31 - TEST LIMIT SWITCH XA1
TEST 30 - CHECK FUSES F1 AND F2
SECTION
TEST 32 - CONTINUITY TEST OF WIRING C1
TEST 33 - CONTINUITY TEST OF WIRING C2
TEST 34 - CHECK N1 AND N2 WIRING
DIAGNOSTIC TESTS
7. Disconnect wire N1 and wire N2 from transformer TX
TEST 35 - CHECK TRANSFORMER TX
DIAGNOSTIC TESTS
SECTION
PART
DIAGNOSTIC TESTS
SECTION
Figure 6. Transformer TX
Air-cooled, Prepackaged Automatic Standby Generators
PART DC CONTROL
TABLE OF CONTENTS
Models 04389, 04758 6 kW NG, 7 kW LP
TRANSFORMER TX
DESCRIPTION AND COMPONENTS
TERMINAL STRIP / INTERCONNECTION TERMINAL
CIRCUIT BOARD
SECTION
WIRE
WIRE
PART
5 AMP FUSE
AUTO-OFF-MANUAL SWITCH
15 AMP FUSE
Figure 5. 15 Amp Fuse Figure 4. The AUTO-OFF-MANUAL Switch
DESCRIPTION AND COMPONENTS
SECTION
PART
Figure 6. Control Panel Component Identification
PART
SECTION
OPERATIONAL ANALYSIS
INTRODUCTION
OPERATIONAL ANALYSIS
SECTION
PART
DC CONTROL
OPERATIONAL ANALYSIS
INITIAL DROPOUT OF UTILITY SOURCE VOLTAGE
SECTION
PART
OPERATIONAL ANALYSIS
SECTION
PART
Page
OPERATIONAL ANALYSIS
UTILITY VOLTAGE DROPOUT AND ENGINE CRANKING
SECTION
PART
OPERATIONAL ANALYSIS
SECTION
PART
DC CONTROL
OPERATIONAL ANALYSIS
ENGINE STARTUP AND RUNNING
SECTION
PART
OPERATIONAL ANALYSIS
SECTION
PART
DC CONTROL
OPERATIONAL ANALYSIS
INITIAL TRANSFER TO THE STANDBY SOURCE
SECTION
PART
OPERATIONAL ANALYSIS
SECTION
PART
DC CONTROL
SECTION
UTILITY VOLTAGE RESTORED / RE TRANSFER TO UTILITY
Figure 6. Circuit Condition - Utility Voltage Restored
OPERATIONAL ANALYSIS
OPERATIONAL ANALYSIS
SECTION
PART
DC CONTROL
OPERATIONAL ANALYSIS
ENGINE SHUTDOWN
SECTION
PART
OPERATIONAL ANALYSIS
SECTION
PART
DC CONTROL
PART
TROUBLESHOOTING FLOW CHARTS
SECTION
DC CONTROL
PART
TROUBLESHOOTING FLOW CHARTS
SECTION
DC CONTROL
PART
TROUBLESHOOTING FLOW CHARTS
SECTION
DC CONTROL
PART
TROUBLESHOOTING FLOW CHARTS
SECTION
DC CONTROL
PART
TROUBLESHOOTING FLOW CHARTS
SECTION
DC CONTROL
PART
TROUBLESHOOTING FLOW CHARTS
SECTION
DC CONTROL
PART
TROUBLESHOOTING FLOW CHARTS
SECTION
DC CONTROL
TEST 42 - TRY A MANUAL START
TEST 41 - CHECK POSITION OF AUTO-OFF MANUAL SWITCH
TEST 43- TEST AUTO-OFF-MANUAL SWITCH
DIAGNOSTIC TESTS
Figure 2. AUTO-OFF-MANUAL Switch Test Points
DIAGNOSTIC TESTS
TEST 44- CHECK WIRE 15/15A/17/239 VOLTAGE
SECTION
DIAGNOSTIC TESTS
TEST 46- CHECK BATTERY
TEST 45- CHECK 15 AMP FUSE
SECTION
DIAGNOSTIC TESTS
TEST 47 - CHECK WIRE 56 VOLTAGE
TEST 48- TEST STARTER CONTACTOR RELAY V-TWIN ONLY
Figure 4. The Wire 56 Circuit
SECTION
TEST 49- TEST STARTER CONTACTOR
DIAGNOSTIC TESTS
PART
SECTION
TEST 50- TEST STARTER MOTOR
DIAGNOSTIC TESTS
PART
PART
DIAGNOSTIC TESTS
SECTION
Figure 10. Check Pinion Gear Operation V-Twin
SECTION
DIAGNOSTIC TESTS
1. A fully charged 12 volt battery is required
PART
SECTION
TEST 51 - CHECK FUEL SUPPLY AND PRESSURE
DIAGNOSTIC TESTS
PART
DIAGNOSTIC TESTS
TEST 53 - CHECK CIRCUIT BOARD WIRE OUTPUT
TEST 52 - TEST FUEL SOLENOID
SECTION
DIAGNOSTIC TESTS
TEST 54 - CHECK FUEL SOLENOID
TEST 55 - CHECK FOR IGNITION SPARK
SECTION
DIAGNOSTIC TESTS
TEST 56 - CHECK SPARK PLUGS
TEST 57- CHECK ENGINE COMPRESSION
SECTION
DIAGNOSTIC TESTS
TEST 58 - CHECK SHUTDOWN WIRE
TEST 59 - CHECK AND ADJUST IGNITION MAGNETOS
SECTION
SECTION
DIAGNOSTIC TESTS
Figure 23. Setting Ignition Magneto Armature Air Gap
PART
Figure 27. Oil Pressure Switch
TEST 60- CHECK OIL PRESSURE SWITCH AND WIRE
DIAGNOSTIC TESTS
SECTION
Figure 28. Testing the Oil Temperature Switch
TEST 61- CHECK HIGH OIL TEMPERATURE SWITCH
DIAGNOSTIC TESTS
SECTION
DIAGNOSTIC TESTS
TEST 62 - CHECK AND ADJUST VALVES
TEST 63 - CHECK FUEL REGULATOR
5. When full load has been achieved, connect a frequency
SECTION
TEST 64 - CHECK BATTERY CHARGE OUTPUT
DIAGNOSTIC TESTS
PART
DIAGNOSTIC TESTS
TEST 66 - CHECK AC VOLTAGE AT BATTERY CHARGER
TEST 65 - CHECK TRANSFORMER TX VOLTAGE OUTPUT
SECTION
DIAGNOSTIC TESTS
TEST 68 - CHECK BATTERY CHARGE WINDING HARNESS
TEST 67 - CHECK BATTERY CHARGE RELAY
SECTION
DIAGNOSTIC TESTS
TEST 69 - CHECK BATTERY CHARGER WIRING
TEST 70 - CHECK ENGINE RUN WINDING
SECTION
AT THE CIRCUIT BOARD
TEST 73 - TEST SET EXERCISE SWITCH
TEST 71 - CHECK N1 AND N2 VOLTAGE
TEST 72 - CHECK UTILITY SENSING VOLTAGE
TEST 76 - CHECK CRANKING AND RUNNING CIRCUITS
TEST 74 - CHECK REMOTE START WIRING IF EQUIPPED
TEST 75 - CHECK BATTERY VOLTAGE CIRCUIT
DIAGNOSTIC TESTS
SECTION
TEST 77 - TEST EXERCISE FUNCTION
DIAGNOSTIC TESTS
PART
Air-cooled, Prepackaged Automatic Standby Generators
PART OPERATIONAL TESTS
TABLE OF CONTENTS
Models 04389, 04758 6 kW NG, 7 kW LP
ELECTRICAL CHECKS
MANUAL TRANSFER SWITCH OPERATION
SYSTEM FUNCTIONAL TESTS
Figure 1. Manual Operation “V-Type” Switch
DANGER
GENERATOR TESTS UNDER LOAD
SECTION
DANGER
SECTION
SETTING THE EXERCISE TIMER
CHECKING AUTOMATIC OPERATION
SYSTEM FUNCTIONAL TESTS
Air-cooled, Prepackaged Automatic Standby Generators
PART DISASSEMBLY
TABLE OF CONTENTS
Models 04389, 04758 6 kW NG, 7 kW LP
10.Remove Rotor Bolt Using a 9/16 socket, remove one rotor bolt
MAJOR DISASSEMBLY
MAJOR DISASSEMBLY
SECTION
PART
MAJOR DISASSEMBLY
SECTION
Figure 4. Engine Adapter Supported by 2”x4” Piece of Wood
16.Remove Engine Using a 13mm socket, remove the
FRONT ENGINE ACCESS
MAJOR DISASSEMBLY
Figure 9. C1 and C2 Connectors Located on the Engine Divider Panel
Air-cooled, Prepackaged Automatic Standby Generators
PART ELECTRICAL DATA
TABLE OF CONTENTS
Models 04389, 04758 6 kW NG, 7 kW LP
PART
WIRING DIAGRAM, 7 KW HOME STANDBY
MODEL
DRAWING #0D5700-C
PART
SCHEMATIC, 7 KW HOME STANDBY
MODEL
DRAWING #0D5701-C
PART
WIRING DIAGRAM, 12 & 15 KW HOME STANDBY
MODEL 4456-0
DRAWING #0C7830-C
PART
SCHEMATIC, 12 & 15 KW HOME STANDBY
MODEL 4456-0
DRAWING #0C7836-C
PART
WIRING DIAGRAM, 7 KW HOME STANDBY
MODEL
DRAWING #0D9013-C 1 OF
PART
WIRING DIAGRAM, 7 KW HOME STANDBY
MODEL
DRAWING #0D9013-C 2 OF
PART
SCHEMATIC, 7 KW HOME STANDBY
MODEL
DRAWING #0D9014-B 1 OF
PART
SCHEMATIC, 7 KW HOME STANDBY
MODEL
DRAWING #0D9014-B 2 OF
PART
MODEL 4456-1
WIRING DIAGRAM, 12 & 15 KW HOME STANDBY
DRAWING #0D8500-B 1 OF
PART
WIRING DIAGRAM, 12 & 15 KW HOME STANDBY
MODEL 4456-1
DRAWING #0D8500-B 2 OF
PART
SCHEMATIC, 12 & 15 KW HOME STANDBY
MODEL 4456-1
DRAWING #0D8501-B 1 OF
PART
SCHEMATIC, 12 & 15 KW HOME STANDBY
MODEL 4456-1
DRAWING #0D8501-B 2 OF
PART
Page
ELECTRICAL DATA
PART
ELECTRICAL DATA
PART
Page
ELECTRICAL DATA
Page
P/N OE3586/Printed in the USA/1.03/Rev
2. If no engine problems are found, go to Test
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1. Repair engine, or replace defective parts, or adjust as necessary
SECTION
PART
SECTION
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3.4 provides detailed instructions for performance of each test
SECTION
PART
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PART
SECTION
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