Generac Power Systems 7 kW NG, 8 kW LP, 10 kW, 13 kW, 14 kW Repair Manual

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Page 1

DIAGNOSTIC

REPAIR

MANUAL

Air-Cooled Product with Nexus Control

MODELS:

7 kW NG, 8 kW LP

9 kW NG, 10 kW LP

13 kW NG, 14 kW LP

15 kW NG, 15 kW LP

16 kW NG, 17 kW LP

18 kW NG, 20 kW LP

STANDBY GENERATORS

Page 2

Foreword

SAFETY

Throughout this publication, DANGER, WARNING, and CAUTION blocks are used to alert the mechanic to special instructions concerning a particular service or operation that might be hazardous if performed incorrectly or carelessly. Observe them carefully. Their definitions are as follows:

After this heading, read instructions that, if not strictly complied with, will result in serious personal injury, including death.

After this heading, read instructions that, if not strictly complied with, could result in serious personal injury, including death.

After this heading, read instructions that, if not strictly complied with, might result in minor or moderate injury.

Four commonly used safety symbols accompany the DANGER, WARNING and CAUTION blocks. The type of information each indicates follows:

This symbol points out important safety information that,



if not followed, could endanger personal safety and/or property of others.

This symbol points out potential explosion hazard.



This symbol points out potential fire hazard.



This symbol points out potential electrical shock hazard.



These “Safety Alerts” alone cannot eliminate the hazards that they signal. Strict compliance with these special instructions plus “common sense” are major accident prevention measures.

Some of the terminology used in this manual may appear differently for product manufactured by the factory and branded under another label.

Generac Name Honeywell Name

TruePower Technology PrecisionPower Technology

Generac OHVI engine Generac OHVI Engine

Rhinocoat Rhinocoat

QuietTest WhisperCheck

Nexus Controller Sync Controller

Nexus Smart Switches Sync Transfer Switches with Load

Nexus Wireless Remote Monitors

Nexus Smart Switches Sync Smar t Switches

Shedding Capability

Sync Wireless Remote Monitors

READ THIS MANUAL THOROUGHL Y

This SERVICE MANUAL has been written and published by Generac to aid our dealers' technicians and company service personnel when servicing the products described herein.

It is assumed that these personnel are familiar with the servicing procedures for these products, or like or similar products manufactured and marketed by Generac, and that they have been trained in the recommended servicing procedures for these products, including the use of common hand tools and any special Generac tools or tools from other suppliers.

Generac could not possibly know of and advise the service trade of all conceivable procedures by which a service might be performed and of the possible hazards and/or results of each method. We have not undertaken any such wide evaluation. Therefore, anyone who uses a procedure or tool not recommended by Generac must first satisfy themselves that neither his nor the products safety will be endangered by the service procedure selected.

All information, illustrations and specifications in this manual are based on the latest product information available at the time of publication.

When working on these products, remember that the electrical system and engine ignition system are capable of violent and damaging short circuits or severe electrical shocks. If you intend to perform work where electrical terminals could be grounded or touched, the battery cables should be disconnected at the battery.

Any time the intake or exhaust openings of the engine are exposed during service, they should be covered to prevent accidental entry of foreign material. Entry of such materials will result in extensive damage when the engine Is started.

During any maintenance procedure, replacement fasteners must have the same measurements and strength as the fasteners that were removed. Metric bolts and nuts have numbers that indicate their strength. Customary bolts use radial lines to indicate strength while most customary nuts do not have strength markings. Mismatched or incorrect fasteners can cause damage, malfunction and possible injury.

Note: Special Notes appear in bold type throughout this publication. While not pertaining to safety, they emphasize procedures, circumstances or specifications that require special attention.

REPLACEMENT PARTS

When servicing this equipment, it is extremely important that all components be properly installed and tightened. If improperly installed and tightened, sparks could ignite fuel vapors from fuel system leaks.

Page 3

Specifications ......................................................................4

Generator Engine

............................................................... 4

.................................................................... 5

Fuel Consumption ................................................... 5

Mounting Dimensions ............................................. 6

Major Features

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

PART 1 – General Information..............................................9

Section 1.1 – Generator Basics

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

Introduction .......................................................... 10

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

Parts Generator Identification

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

Section 1.2 – Installation Basics .......................................11

Introduction .......................................................... 11

Selecting a Location NFPA 37 Code Requirements

............................................. 11

................................ 11

Grounding the Generator ....................................... 11

The Fuel Supply .................................................... 11

Natural Gas Fuel Interconnections ......................... 14

Transfer Switch / Load Center ............................... 14

Power Source and Load Lines ...............................14

System Control Interconnections .......................... 15

Section 1.3 – Preparation Before Use ................................ 16

Introduction .......................................................... 16

Reconfiguring the fuel system ............................... 17

Section 1.4 – Measuring Electricity ...................................19

Meters .................................................................. 19

The VOM .............................................................. 19

Measuring AC Voltage ...........................................19

Measuring DC Voltage ...........................................19

Measuring AC Frequency ...................................... 19

Measuring Current ................................................ 20

Measuring Resistance ........................................... 20

Electrical Units ...................................................... 21

Ohm’s Law ........................................................... 21

Section 1.5 – Testing, Cleaning and Drying ........................ 22

Visual Inspection .................................................. 22

The Megohmmeter ............................................... 22

Cleaning the Generator .......................................... 23

Drying the Generator ............................................. 23

Section 1.6 – Operating Instructions ................................. 25

Control Panel ........................................................ 25

User Interface ....................................................... 25

To Select Automatic Operation .............................. 26

Manual Operation.................................................. 26

Section 1.7 – Automatic Operating Parameters .................. 27

Introduction .......................................................... 27

Utility Failure ......................................................... 27

Cranking ............................................................... 27

Cranking Conditions Load Transfer Parameters

.............................................. 27

..................................... 27

Utility Restored ..................................................... 28

Section 1.8 – General Maintenance ................................... 29

Introduction Maintenance Message

.......................................................... 29

.......................................... 29

Air Filter ................................................................ 29

Spark Plugs .......................................................... 29

Visual Inspection Corrosion Protection

.................................................. 29

............................................. 30

Valve Clearance .................................................... 30

Battery ................................................................. 30

Section 1.9 – Wireless Remote

......................................... 32

Wireless Monitor................................................... 32

Wireless Basic Troubleshooting.

............................ 32

Wireless Advanced Module ................................... 33

Wireless Advanced Features ................................. 33

Wireless Advanced Troubleshooting. ..................... 33

Section 1.10 – Control Panel Menu System Navigation ...... 35

Main Menu ........................................................... 35

Section 1.11 – General Troubleshooting Guidelines ........... 38

Introduction .......................................................... 38

Recommended Tools ............................................ 38

Troubleshooting Reminders and Tips ..................... 38

Important Note concerning connectors ................. 38

PART 2 – AC Generators ....................................................39

Section 2.1 – Description and Components ....................... 40

Introduction .......................................................... 40

Engine-Generator Drive System ............................. 40

Alternator Assembly ............................................. 40

Other AC Generator Components .......................... 40

Section 2.2 – Operational Analysis .................................... 42

Rotor Residual Magnetism .................................... 42

Field Boost ........................................................... 42

Operation .............................................................. 42

Section 2.3 – Troubleshooting Flowcharts ......................... 44

Introduction .......................................................... 44

Problem 1 – Generator Shuts Down

for Under-voltage .............................. 44

Problem 2 – Generator Shuts Down

for High Voltage ................................ 45

Problem 3 – Voltage and Frequency Drop Excessively When Loads Are Applied . 46

Problem 4 – Unstable Voltage or Incorrect Output Which is Not Triggering a Shutdown .. 46

Section 2.4 – Diagnostic Tests .......................................... 47

Introduction .......................................................... 47

Safety ................................................................... 47

Page 1

Page 4

AC Troubleshooting............................................... 47

Test 1 – Check AC Output Voltage Test 3 – Calibrate Voltage

...................................... 48

......................... 47

Test 4 – Fixed Excitation Test/

Rotor Amp Draw Test ............................... 48

Test 5 – Test Sensing CircuitWires 11 and 44 ........ 51

Test 6 – Test Excitation WindingCircuit 2 and 6 Test 7 – Test the Stator with a VOM

....................... 52

...... 52

Test 8 – Resistance Check of Rotor Circuit ............ 54

Test 9 – Check Brushes and Slip Rings ................. 54

Test 10 – Test Rotor Assembly Test 11 – Check AC Output Frequency

.............................. 55

................... 55

Test 12 – Check Stepper Motor Control ................. 56

Test 14 – Check Voltage and

Frequency under Load ........................... 57

Test 15 – Check for an Overload Condition Test 16 – Check Engine Condition

......................... 57

............ 57

PART 3 – Transfer Switch ..................................................59

Section 3.1 – Description and Components ....................... 60

Introduction .......................................................... 60

Enclosure ............................................................. 60

Transfer Switch Contactor ..................................... 61

Transfer Relay ....................................................... 61

Neutral Lug ........................................................... 62

Manual Transfer Handle ........................................ 62

Customer Connections ......................................... 62

Fuse Holder .......................................................... 63

Section 3.2 – Operational Analysis .................................... 64

Utility Source Voltage Available.............................. 64

Utility Source Voltage Failure ................................. 65

Transferring to Standby ......................................... 66

Transferred to Standby .......................................... 67

Utility Restored ..................................................... 68

Utility Restored, Transferring back to Utility ............ 69

Utility Restored, Transferred back to Utility ............ 70

Transferred back to Utility, Generator Shutdown ..... 71

Section 3.3 – Troubleshooting Flowcharts ......................... 73

Introduction .......................................................... 73

Problem 6 – In Automatic Mode,

No Transfer to Standby ...................... 73

Problem 7 – In Automatic Mode, Generator Starts When Loss of Utility Occurs, Generator Shuts Down When Utility Returns, but There Is No Retransfer to Utility or Generator Transfers to Standby During Exercise or in

Manual Mode With Utility Available ..... 74

Problem 8 – Unit Starts and Transfers When

Utility Power is Available ...................74

Problem 9 – Blown F1 or F2 Fuse ..........................74

Problem 10 – Blown T1 Fuse ................................ 74

Page 2

Section 3.4 – Diagnostic Tests .......................................... 76

Introduction Safety

.......................................................... 76

................................................................... 76

Transfer Switch Troubleshooting ..........................76

Test 20 – Check Voltage at

Terminal Lugs E1 and E2 ....................... 76

Test 21 – Check Manual Transfer Switch Operation

Test 22 – Check 23 and 194 Circuit

................................... 77

...................... 78

Test 23 – Test Transfer Relay ................................79

Test 24 – Test Standby Control Circuit ................... 79

Test 25 – Check Wire 23 Test 26 – Utility Control Circuit

....................................... 81

............................. 83

Test 27 – Test Limit Switches ................................ 83

Test 28 – Check Fuses F1 and F2 .......................... 84

Test 29 – Check Fuse F3 Test 30 – Check Main Circuit Breaker

...................................... 84

.................... 84

Test 32 – Check N1 and N2 Wiring ........................ 85

Test 33 – Check N1 and N2 Voltage ...................... 85

Test 34 – Check Utility Sensing Voltage

at the Circuit Board ................................ 86

Test 35 – Check Utility SENSE Voltage ................... 86

Test 36 – Check T1 Wiring .................................... 86

PART 4 – Engine/DC Control ..............................................89

Section 4.1 – Description and Components ....................... 90

Introduction .......................................................... 90

Customer Connection ........................................... 90

Controller ............................................................. 90

LED Display .......................................................... 90

Battery Charger .................................................... 90

7.5 Amp Fuse ....................................................... 91

Starter Contactor Relay/Solenoid .......................... 91

Common Alarm Relay .......................................... 92

Connector Pin Descriptions ................................... 92

Menu System Navigation ...................................... 93

Section 4.2 – Engine Protective Devices ............................ 94

Introduction .......................................................... 94

Low Battery Warning ............................................ 94

Low Oil Pressure .................................................. 94

High Temperature Switch ...................................... 94

Overspeed ............................................................ 94

RPM Sensor Failure .............................................. 94

Overcrank ............................................................. 94

Under-frequency ................................................... 95

Clearing an Alarm ................................................. 95

Section 4.3 – Operational Analysis .................................... 96

Introduction .......................................................... 96

Utility Source Voltage Available.............................. 96

Page 5

Initial Dropout of Utility Source Voltage .................. 98

Utility Voltage Failure and Engine Cranking Engine Startup and Running

................................ 102

........... 100

Transfer to Standby ............................................. 104

Utility Voltage Restored and Re-transfer to Utility . 106 Engine Shutdown

Section 4.4 – Troubleshooting Flowcharts

................................................ 108

....................... 110

Problem 14 – Engine Will Not Crank

When Utility Voltage Fails ..............110

Problem 15 – Engine Will Not Crank When AUTO-OFF-MANUAL Switch

is Set To MANUAL ........................ 110

Problem 16 – Engine Cranks But Will Not Start

.... 111

Problem 17 – Engine Starts Hard And Runs Rough / Lacks Power / Backfires

... 112

Problem 18 – Shutdown Alarm/Fault Occurred .... 113

Problem 19 – 7.5 Amp Fuse (F1) Blown .............. 114

Problem 20 – Generator Will Not Exercise ........... 114

Problem 21 – No Low Speed Exercise ................. 114

Problem 22 – Battery is Dead ............................. 114

Section 4.5 – Diagnostic Tests ........................................ 115

Introduction ........................................................ 115

Safety ................................................................. 115

Engine/DC Troubleshooting ................................ 115

Test 40 – Check position of

AUTO-OFF-MANUAL Switch ................. 115

Test 41 – Try a Manual Start ............................... 116

Test 42 – Test the AUTO-OFF-MANUAL Switch .... 116

Test 43 – Test Auto Operations of Controller ........ 116

Test 44 – Check 7.5 Amp Fuse............................ 117

Test 45 – Check Battery ...................................... 117

Test 46 – Check Wire 56 Voltage ......................... 118

Test 47 – Test Starter Contactor Relay

(V-Twin Only) ....................................... 119

Test 48 – Test Starter Contactor .......................... 119

Test 49 – Test Starter Motor ................................ 120

Test 50 – Check Fuel Supply and Pressure .......... 122

Test 51 – Check Controller Wire 14 Outputs ........ 123

Test 52 – Check Fuel Solenoid ............................ 124

Test 53 – Check Choke Solenoid ......................... 125

Test 55 – Check for Ignition Spark ....................... 127

Test 57 – Check Condition of Spark Plugs ........... 128

Test 58 – Check Engine / Cylinder Leak

Down Test / Compression Test ............ 129

Test 59 – Check Shutdown Wire ......................... 130

Test 60 – Check and Adjust Ignition Magnetos .... 131

Test 61 – Check Oil Pressure Switch And Wire 86 . 133

Test 62 – Check High Oil Temperature Switch ...... 134

Test 63 – Check and Adjust Valves ...................... 135

Test 64 – Check Wire 18 Continuity ..................... 135

Test 65 – Test Exercise Function ......................... 136

Test 66 – Test Cranking and Running Circuits Test 67 – Test Run Circuit

................................... 137

...... 137

Test 68 – Test Crank Circuit ................................ 138

Test 69 – Test TRANSFER RELAY Circuit ............. 139

Test 70 – Check to see if Low Speed Function is enabled

Test 71 – Check operation of the Choke Solenoid

.............................. 139

139

Test 75 – Test 120 Volt Input (T1) ....................... 140

Test 76 – Verify DC Voltage Output

of the Controller ................................... 140

Test 77 – Check Wire 13 and Wire 0 Test 78 – Test DC Charge Current to the Battery

................... 140

.. 140

Test 79 – Check T1 Voltage at

Customer Connections ......................... 141

Test 80 – Check T1 Voltage at J5 Connector ........ 141

Test 81 – Check T1 Voltage in Transfer Switch Test 82 – Test F3 Fuse Circuit

............................. 142

.... 141

PART 5 – Operational Tests ..............................................143

Section 5.1 – System Functional Tests ............................ 144

Introduction ........................................................ 144

Manual Transfer Switch Operation ....................... 144

Electrical Checks ................................................ 144

Generator Tests Under Load ................................ 145

Checking Automatic Operation ............................ 146

Section 5.2 – Setup Procedures ...................................... 147

Setting the Exercise Time .................................... 147

Activation Process .............................................. 147

PART 6 – Disassembly .....................................................149

Section 6.1 – Major Disassembly .................................... 150

Front Engine Access ........................................... 150

Major Disassembly ............................................. 154

Torque Requirements .......................................... 160

PART 7 – Electrical Data ..................................................175

Wiring Diagram, 8 kW Home Standby .............................176

Electrical Schematic, 8 kW Home Standby ...................... 178

Wiring Diagram, 10-14 kW Home Standby ...................... 179

Electrical Schematic, 10-14 kW Home Standby ............... 180

Electrical Schematic, 17 kW Home Standby .................... 182

Wiring Diagram, 17 kW Home Standby ...........................184

Electrical Schematic, 20 kW Home Standby .................... 186

Electrical Schematic, Home Standby Transfer Switch....... 188

Wiring Diagram, Home Standby Transfer Switch .............. 190

Electrical Formulas .........................................................192

Appendix A Supplemental Worksheets.............................193

Appendix B Index of Figures and Tables ..........................203

Index of Figures .............................................................. 204

Index of Tables ................................................................205

Page 3

Page 6

Specifications

GENERATOR

Unit

Rated Max. Continuous Power Capacity

(Watts*)

Rated Voltage 240

Rated Voltage at No-Load (NG)

Older controller P/N 0H6680A

Newer controller P/N 0H6680B

Rated Max. Continuous Load Current

(Amps)

240 Volts (LP/NG) 33.3/29.2 41.6/37.5 54.2/54.2 58.3/54.2 62.5/62.5 66.6/66.6 70.8/66.6 83.3/75.0

Main Line Circuit Breaker

Circuits*** 50A, 240V - - 1 - 1 1 1 -

40A, 240V - 1 1 1 1 1 1 -

30A, 240V 1 1 - - - - - -

20A, 240V 1 - 1 1 1 1 1 -

20A, 120V 3 3 4 6 5 5 5 -

15A, 120V 3 5 4 4 5 5 5 -

Phase 1

Number of Rotor Poles 2

Rated AC Frequency 60 Hz

Power Factor 1

Battery Requirement Group 26R, 12 Volts and 525 CCA Minimum

Weight (unit only in lbs.)

Enclosure Steel Steel/Aluminum Steel Steel

Normal Operating Range This unit is tested in accordance to UL 2200 standards with an operating temperature of 20° F (-29° C) to 122°F. (50° C). For

* 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.

8 kW 10 kW 13 kW 14 kW 15 kW 16 kW 17 kW 20 kW

7,000 NG

8,000 LP

35 Amp 45 Amp 55 Amp 60 Amp 65 Amp 65 Amp 65 Amp 100 Amp

340 387/353 439 439 455/421 439 455/421 450

areas where temperatures fall below 32° F (0° C), a cold weather kit is highly recommended. When operated above 77° F (25° C) there may be a decrease in engine power. (Please reference the engine specifications section).

9,000 NG

10,000 LP

13,000 NG

13,000 LP

13,000 NG

14,000 LP

15,000 NG

15,000 LP

250-254 240-244

Steel/Aluminum Steel Steel/Aluminum Aluminum

16,000 NG

16,000 LP

16,000 NG

17,000 LP

18,000 NG

20,000 LP

STATOR WINDING RESISTANCE VALUES / ROTOR RESISTANCE*

8 kW 10 kW 13 kW 14 kW 15 k W 16 kW 17 kW 20 kW

Power Winding: Across 11 & 22 0.1660-

0.1930

Power Winding: Across 33 & 44 0.1660-

0.1930

Sensing Winding: Across 11 & 44 0.378-.4392 0.425-0.4938 0.2484-

Excitation Winding: Across 2 & 6 1.0318-

0.1930

Rotor Resistance 6.30-7.32 6.30-7.32 7.58-8.80 7.58-8.81 8.37-9.72 8.37-9.72 8.37-9.72 9.54-11.10

* Resistance values shown are based on new windings at 20° C. Actual readings may vary based on type of meter used and any other components or

connections included in the circuit being tested.

Page 4

0.1895-

0.2203

0.1895-

0.2203

1.0935-

1.2708

0.1003-

0.1165

0.1003-

0.1166

0.2887

0.876-1.017 0.876-1.018 0.780-0.906 0.780-0.906 0.780-0.906 0.7318-

0.1003-

0.1165

0.1003-

0.1166

0.2484-

0.2888

0.0746-

0.0866

0.0746-

0.0866

0.197-0.229 0.197-0.229 0.197-0.229 0.137-0.1594

0.0746-

0.0866

0.0746-

0.0866

0.0746-

0.0866

0.0746-

0.0866

0.0415-

0.0483

0.0415-

0.0483

0.8504

Page 7

ENGINE

Specifications

Model

Type of Engine GH-410 GT-530 GT-990 GT-999

Number of Cylinders 1 2 2 2

Rated Horsepower @ 3,600 rpm 14.8 18 32 36

Displacement 407cc 530cc 992cc 999cc

Cylinder Block Aluminum w/Cast Iron Sleeve

Valve Arrangement Overhead Valves

Ignition System Solid-state w/Magneto

Recommended Spark Plug RC14YC BPR6HS RC14YC RC12YC

Spark Plug Gap 0.76 mm (0.030 inch) 0.76 mm (0.030 inch) 1.02 mm (0.040 inch) 0.76 mm (0.030 inch)

Compression Ratio 8.6:1 9.5:1 9.5:1 9.5:1

Starter 12 VDC

Oil Capacity Including Filter Approx. 1.5 Qts Approx. 1.7 Qts Approx. 1.9 Qts Approx. 1.9 Qts

8 kW 10 kW 13/14/15/16/17 kW 20 kW

Recommended Oil Filter Part # 070185F

Recommended Air Filter Part # 0G3332 Part # 0E9581 Part # 0C8127 Part # 0G5894

Operating RPM 3,600

FUEL CONSUMPTION

Model # Natural Gas* LP Vapor**

1/2 Load Full Load 1/2 Load Full Load

7/8 kW 77 140 0.94/34 1.68/62

9/10 kW 102 156 1.25/46 1.93/70

13/13 kW 156 220 1.55/57 2.18/80

13/14 kW 156 220 1.56/58 2.30/84

15/15k W 171 244 1.49 / 54 2.35/85

16/16 kW 183 261 1.59/58 2.51/91

16/17 kW 183 261 1.61/59 2.57/94

18/20 kW 206 294 1.89/69 2.90/106

* Natural gas is in cubic f eet per hour .

**LP is in gallons per hour/cubic feet per hour.

Values given are approximate.

Page 5

Page 8

Specifications

MOUNTING DIMENSIONS

Page 6

Figure 1.

Page 9

MOUNTING DIMENSIONS

Specifications

Page 7

Page 10

Specifications

MAJOR FEATURES

Oil

Dipstick

Exhaust

Enclosure

Composite Base Oil Filter Battery Compartment

Data Label

(see sample)

Figure 2. 8kW, Single Cylinder, GH-410 Engine

(door removed)

Control

Panel

Circuit

Breaker

Air Filter

Fuel Inlet

(back)

Fuel

Regulator

Exhaust

Enclosure

Oil

Dipstick

Composite Base Oil Filter Battery Compartment

Data Label

(see sample)

Control

Panel

Figure 3. 10kW, V-twin, GT-530 Engine

(door removed)

Circuit

Breaker

Air

Filter

Fuel Inlet

(back)

Fuel

Regulator

Page 8

Exhaust

Enclosure

Data Label

Oil

Dipstick

(see sample)

Air Filter

Control

Panel

Breakers

Fuel Inlet

Composite Base Oil Filter Battery Compartment

Figure 4. 13, 14, 15, 16, 17 and 20kW, V-twin,

GT-990/GT-999 Engine (door removed)

Circuit

(back)

Fuel

Regulator

Page 11

PART 1

GENERAL

INFORMATION

Air-cooled, Automatic

Standby Generators

Section 1.1 – Generator Basics ................................................................10

Introduction .............................................................................. 10

Parts ......................................................................................... 10

Generator Identification ............................................................. 10

Section 1.2 – Installation Basics ...............................................................11

Introduction .............................................................................. 11

Selecting a Location .................................................................. 11

NFPA 37 Code Requirements ..................................................... 11

Grounding the Generator ........................................................... 11

The Fuel Supply.........................................................................11

Natural Gas Fuel Interconnections .............................................. 14

Transfer Switch / Load Center ....................................................14

Power Source and Load Lines ................................................... 14

System Control Interconnections .............................................. 15

Section 1.3 – Preparation Before Use .......................................................16

Introduction .............................................................................. 16

Reconfiguring the fuel system ...................................................17

Section 1.4 – Measuring Electricity ...........................................................19

Meters ...................................................................................... 19

The VOM ................................................................................... 19

Measuring AC Voltage ............................................................... 19

Measuring DC Voltage ............................................................... 19

Measuring AC Frequency ...........................................................19

Measuring Current .................................................................... 20

Measuring Resistance ............................................................... 20

Electrical Units .......................................................................... 21

Ohm’s Law ............................................................................... 21

Section 1.5 – Testing, Cleaning and Drying ...............................................22

Visual Inspection ....................................................................... 22

The Megohmmeter .................................................................... 22

Cleaning the Generator .............................................................. 23

Drying the Generator ................................................................. 23

TABLE OF CONTENTS

SECTION TITLE PAGE

1.1 Generator Basics 10

1.2 Installation Basics 11

1.3 Preparation Before Use 16

1.4 Measuring Electricity 19

1.5 Testing, Cleaning and Drying 22

1.6 Operating Instructions 25

1.7 Automatic Operating Parameters 27

1.8 General Maintenance 29

1.9 Wireless Remote 32 Control Panel Menu System

1.10 Navigation

General T roubleshooting

1.11 Guidelines

Section 1.6 – Operating Instructions ......................................................... 25

Control Panel ............................................................................25

User Interface ........................................................................... 25

To Select Automatic Operation ................................................... 26

Manual Operation ...................................................................... 26

Section 1.7 – Automatic Operating Parameters .........................................27

Introduction .............................................................................. 27

Utility Failure .............................................................................27

Cranking ................................................................................... 27

Cranking Conditions .................................................................. 27

Load Transfer Parameters .......................................................... 27

Utility Restored ..........................................................................28

Section 1.8 – General Maintenance ..........................................................29

Introduction .............................................................................. 29

Maintenance Message............................................................... 29

Air Filter .................................................................................... 29

Spark Plugs .............................................................................. 29

Visual Inspection ....................................................................... 29

Corrosion Protection ................................................................. 30

Valve Clearance ......................................................................... 30

Battery ...................................................................................... 30

Section 1.9 – Wireless Remote .................................................................32

Wireless Monitor ....................................................................... 32

Wireless Basic Troubleshooting. ................................................32

Wireless Advanced Module ....................................................... 33

Wireless Advanced Features ...................................................... 33

Wireless Advanced Troubleshooting. .........................................33

Section 1.10 – Control Panel Menu System Navigation .............................35

Main Menu ................................................................................ 35

Section 1.11 – General Troubleshooting Guidelines ...................................38

Introduction .............................................................................. 38

Recommended Tools ................................................................. 38

Troubleshooting Reminders and Tips ......................................... 38

Important Note concerning connectors ...................................... 38

Page 9

Page 12

Section 1.1

Generator Basics

PART 1

GENERAL INFORMATION

INTRODUCTION

This diagnostic repair manual has been prepared especially for familiarizing service personnel with the testing, troubleshooting and repair of the air-cooled product that utilizes the Nexus controller. Every effor t has been expended to ensure that the information and instructions in the manual are both accurate and current. However, the manufacture reserves the right to change, alter or otherwise improve the product at any time without prior notification.

The manual has been divided into several PARTS. Each PART has been divided into SUBSECTIONS and each subsection consists of several sub headings.

It is not the manufactures intent to provide detailed disassembly and reassembly of the entire Residential product line. It is the manufactures 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.

PARTS

Part 1 – Provides the basic understanding of the generator as well as basic installation information and operating instructions.

Part 2 – Provides the basics of the AC alternator design and the AC troubleshooting portion of the manual.

Part 3 – Provides the troubleshooting and diagnostic testing procedure for the pre-packaged 10,12,14,16 circuit EZ Switch™ transfer switches.

Part 4 – Provides the troubleshooting and diagnostic testing procedure for engine related problems and the Nexus™ Controller.

Part 5 – Provides the basic operational and system function testing to ensure proper operation of the unit.

Part 6 – Provides detailed step-by-step instructions for the replacement of the rotor/stator and engine.

Part 7 – Illustrates all of the electrical and wiring diagrams for the various kW ranges and transfer switches.

Item # 0055555

Serial

Volts

Amps

Watts 1 PH, 60 HZ, RPM 3600

RAINPROOF ENCLOSURE FITTED

MAX OPERATING AMBIENT

NEUTRAL FLOATING

MAX LOAD UNBALANCED - 50%

1234567

120/240 AC

108.3/108.3 13000

CLASS H INSULATION

TEMP -

FOR STANDBY SERVICE

25°C

MODEL

SERIAL

VOLTS

AMPS CONTROLLER

1 PH, 60 Hz, RPM 3600

RAINPROOF ENCLOSURE FITTED

RATED AMBIENT TEMP - 25°C

FOR STANDBY SERVICE

NEUTRAL FLOATING

MAX LOAD UNBALANCE-50%

0055555 1234567

120/240 AC

108.3/108.3

P/N

CLASS H INSULATION

GENERAC POWER SYSTEMS

0H6680B

WHITEWA TER, WI

53190 U.S.A.

Data Plate

The data plate that is affixed to the generator contains important information pertaining to the unit, including its model number, serial number, amperage rating, and voltage rating. The information from this data plate may be required when requesting information, ordering parts, etc.

Item Number

Many home standby generators manufactured are 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.

GENERATOR IDENTIFICATION

The air-cooled product utilizes four different engines over various kW ranges. It is important to know the size of the engine before attempting a repair because some testing procedures will be different from engine to engine.

410cc Engine 8kW

•Overhead Valve

•Single Cylinder

•Nexus™ Controller

530cc Engine 10kW

•Overhead Valve

•Twin Cylinders

•Nexus™ Controller

990cc Engine 12-17kW

•Overhead Valve

•Twin Cylinders

•Nexus™ Controller

999cc Engine 20kW

•Overhead Valve

•Twin Cylinders

•Nexus™ Controller

MODEL # SERIAL #

Model Number -Serial Number -

0055555 1234567 120/240 AC

1PH, 60Hz, 3600 RPM, CLASS F INSULATION

RAINPROOF ENCLOSURE FITTED

RATED AMBIENT TEMP - 40°C

FOR STANDBY SERVICE, NEUTRAL FLOATING

WATTS VOLTS AMPS

13000

108.3/108.3

Page 10

Figure 5. Typical Data Plates

Page 13

GENERAL INFORMATION

PART 1

Section 1.2

Installation Basics

INTRODUCTION

Information is provided in this section to ensure the service technician will have a basic knowledge of installation requirements for home standby systems. Installation problems that arise often relate to poor or unauthorized installation practices.

A typical home standby electric system is shown in Figure 7. Installation of a system includes the following:

•Selecting a location

•Grounding the Generator

•Providing the fuel supply

•Mounting the load center

•Connecting power source and load lines

•Connecting system control wiring

•Post installation tests and adjustments

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 consists of N1, N2, T1, 194, and 23. In addition, a Wire 0 must be connected for use with Nexus Smart Switches. Control system interconnection leads must be run in a conduit that is separate from the AC power leads. Recommended wire gauge size depends on length of the wire:

Annex A — Explanatory Material

A4.1.4 (2) Means of demonstrating compliance are by means of full-scale fire test or by calculation procedures.

Generator exhaust contains DEADLY carbon monoxide



gas. This dangerous gas can cause unconsciousness or death. Do not place the unit near windows, doors, fresh air intakes (furnaces, etc) or any openings in the building or structure, including windows and doors of an attached garage.

The air-cooled product line has under gone the required testing, which meets the requirements of exception 2. The criteria for the testing were to determine the worst-case fire scenario within the Generator and to determine the ignitability of items outside the engine enclosure at various distances. The enclosure is constructed of non-combustible materials. The results and conclusion from the independent testing lab indicated that any fire within the Generator enclosure would not pose any ignition risk to nearby combustibles or structures, with or without fire service personnel response.

Based on the required testing, the requirement of NFPA 37, Sect 4.1.4, the guidelines for the 8, 10, 12, 13, 14, 15, 16, 17 and 20kW units changed to 18 inches (457mm) from the back side of the Generator to a stationary wall or building. For adequate maintenance and airflow clearance, the area above the Generator should be at least three (3) feet with a minimum of three (3) feet at the front and ends of the enclosure. This includes, but not limited to trees, shrubs, and vegetation that could obstruct airflow. See Figures 1 and 6 for further details.

Max. Cable Length Recommended Wire Size

35 feet (10.67m) No. 16 AWG.

60 feet (I8.29m) No. 14 AWG.

90 feet (27.43m) No. 12 AWG.

NFPA 37 CODE REQUIREMENTS

The National Fire Protection Association (NFPA) has established standards for the installation and use of stationary combustion engines. This code limits the spacing of an enclosed Generator set from a structure or wall. NFPA 37 states:

NFPA 37, Section 4.1.4, Engines Located Outdoors. Engines, and their weatherproof housings if provided, that are installed outdoors shall be located at least 5 feet from openings in walls and at least 5 feet from structures having combustible walls. A minimum separation shall not be required where the following conditions exist:

1. The adjacent wall of the structure has a fire resistance rating of at least 1 hour.

2. The weatherproof enclosure is constructed of noncombustible materials and it has been demonstrated that a fire within the enclosure will not ignite combustible materials outside the enclosure.

GROUNDING THE GENERA TOR

The National Electric Code requires that the frame and external electrically conductive parts of the Generator be properly 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. Consult with local electrician for grounding requirements in the area.

THE FUEL SUPPLY

Natural gas is the primary fuel source utilized for the operating, testing and adjusting of units with air-cooled engine. When it is necessary, it is possible to convert units with air-cooled engines to use liquid propane vapor (LPV). See Section 1.4 “Reconfiguring the Fuel System” for the conversion procedure.

LPV gas is usually supplied as a liquid in high-pressure tanks. The air-cooled product requires a “vapor withdrawal” type of fuel supply system when Liquid Propane (LP) 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 is delivered to the Generator may

Page 11

Page 14

Section 1.2

Installation Basics

No windows or openings in the wall permitted

within 5 feet from any point of the generator.

PART 1

GENERAL INFORMATION

60 inches 60 inches

36 inches

These guidelines are based upon fire testing of the generator enclosure and the manufacturer’s requirement for air flow for proper operation. Local codes may be different and more restrictive than what is described here.

Existing Wall

18 inches

Minimum Distance

Top of Generator

36 inches

Clearance from windows,

36 inches

Clearance from the ends and front of the generator should be 36 inches. This would include shrubs, trees and any kind of vegetation. Clearance at the top should be a minimum of 48 inches from any structure, overhang or projections from the wall. The generator should not be placed under a deck or other structure that is closed in and would limit or contain air flow.

doors, any openings in the wall, shrubs or vegetation over 12” in height

60” Minimum

60” Recommended

Minimum From Ends

Generator

18 inches

Minimum

This drawing supersedes installation instructions in all Generac air-cooled installation and owner’s manuals dated previous to May 26, 2007.

Figure 6. NFPA 37 Code Requirements

Page 12

Page 15

GENERAL INFORMATION

PART 1

Section 1.2

Installation Basics

Figure 7. A Typical Home Standby Electric System

Page 13

Page 16

Section 1.2

Installation Basics

PART 1

GENERAL INFORMATION

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.

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: To maintain proper fuel pressure a primary regulator is required.

LP and Natural Gas are both highly explosive. Gaseous



fuel lines must be properly purged and tested for leaks before this equipment is placed into service and periodically thereafter. Procedures used in gaseous fuel leakage tests must comply strictly with applicable fuel gas codes. Do not use flame or any source of heat to test for gas leaks. No gas leakage is permitted. LP gas is heavier than air and tends to settle in low areas. Natural gas is lighter than air and tends to settle in high places. Even the slightest spark can ignite these fuels and cause an explosion.

Use a flexible length of hose between the Generator fuel 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 lines is nine (9) inches. Exceeding the bend radius can cause the fittings to crack.

TRANSFER SWITCH / LOAD CENTER

Electrical code requires the use of a transfer switch, to prevent electrical feedback between the Utility and Standby power sources, and to transfer electrical loads from one power supply to another safely. See Section 3.1 for further information.

POWER SOURCE AND LOAD LINES

The Utility supply lines, the Standby supply lines, and electrical Load lines must all be connected to the proper terminal lugs in the transfer switch. In single phase systems only with a 2-pole CONTACTOR the following installation procedure applies. Connect the two Utility source (hot) lines to the CONTACTOR terminal lugs labeled N1 and N2. Connect the Standby source (hot) lines to the CONTACTOR terminal lugs labeled E1 and E2. Connect the Load lines to the CONTACTOR terminal lugs labeled T1 and T2. Connect the Utility, Standby, and Load Neutral lines to the NEUTRAL block in the transfer switch.

NATURAL GAS FUEL INTERCONNECTIONS

5-7” WC REGULA T OR TO HOUSEHOLD

GAS METER CAPABLE OF PROVIDING NATURAL GAS

SAFETY

SHUT OFF

VALVE

TRAP

0000001

Figure 8. Proper Fuel Installation

FUEL FLOW OF:

140,000 (7 kW) 156,000 (9 kW) 215,000 (12 kW) 220,000 (13 kW) 245,000 (15kW) 261,000 (16 kW) 294,000 (18 kW)

+HOUSEHOLD APPLIANCES

BTU/HOUR

(BASED ON 1000 BTU/CU FT)

GAS MAIN

2-5 PSI

Page 14

Page 17

GENERAL INFORMATION

PART 1

SYSTEM CONTROL INTERCONNECTIONS

The system control wiring when properly connected monitors Utility source voltage for drop out below a preset value. When voltage drops below a preset level, the Generator will start in automatic and transfer electrical Loads to the “Standby” position. On restoration of Utility source voltage above a preset value, retransfer of electrical loads from the “Standby” position to the “Utility” position will occur and the Generator will shutdown.

The transfer switch and the Generator will both have a terminal strip labeled “Customer Connections.” The connections are as follows:

Table 1. Typical Control Wiring Connections

Wire # Purpose

194 Provides 12VDC to the transfer relay

23 Switched to ground for transfer relay operation

N1 240VAC sensing for the controller

N2 240VAC sensing for the controller

T1 Provides 120VAC from Load side of the

CONTACTOR for battery charging

209 Connects to 210 for an alarm

210 Connects to 209 for an alarm

0 Provides a DC common for Nexus Smart

Switches

Section 1.2

Installation Basics

Page 15

Page 18

Section 1.3

Preparation Before Use

PART 1

GENERAL INFORMATION

INTRODUCTION

It is the responsibility of the installer to ensure that the Generator installation was performed properly. A careful inspection must be performed when the installation is complete. 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 as well.

Prior to initial startup of the unit, the installer must ensure that the Generator has been properly prepared for use. This includes the following:

•An adequate supply of the correct fuel must be available for Generator operation.

•The engine must be properly serviced with the recommended oil.

•With liquid propane (LP), 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 specification of the 1997 California Air Resources Board for tamper-proof dual fuel systems. The unit will run on natural gas or LP, but it has been factory set and tested to run on natural gas. When the change from natural gas to LP is needed, the fuel system needs to be re-configured. See Section

1.4 “Reconfiguring the Fuel System” for further information.

Recommended fuels should have a British Thermal Unit (BTU) content of at least 1,000 BTU’s per cubic feet for natural gas; or at least 2,520 BTU’s per cubic feet for LP. Ask the fuel supplier for the BTU content of the fuel.

Recommended fuel pressures for natural gas and liquid propane vapor (LPV) are as follows:

LPV NG

Minimum Water Column 10 inches 5 inches

Maximum Water Column 12 inches 7 inches

Note: All pipe sizing, construction and layout must comply with NFPA 54 for natural gas applications and NFPA 58 for liquid propane applications. After installation, verify that the fuel pressure NEVER drops below five (5) inches water column for natural gas or ten (10) inches water column for LPV.

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 fittings.

Table 2. Fuel Pipe Sizing

Natural Gas

Table values are maximum pipe run in feet

KW 0.75" 1" 1.25" 1.5" 2" 2.5" 3"

7-8 55 200 820

10 20 85 370 800

13-14 10 50 245 545

15-17 40 190 425

20 20 130 305 945

Liquid Propane Vapor

Table values are maximum pipe run in feet

KW 0.75" 1" 1.25" 1.5" 2" 2.5" 3"

7-8 165 570

10 70 255 1000

13-14 45 170 690

15-17 25 130 540

20 15 115 480

Notes:

•Pipe sizing is based on 0.5” H20 pressure drop

•Sizing includes a nominal number of elbows and tees

•Please verify adequate service and meter sizing

Gaseous fuels such as natural gas and LPV are highly



explosive. Even 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: Code requires a minimum of one approved manual shutoff valve installed in the gaseous fuel supply line. The valve must be easily accessible. Local codes determine the proper location.

Fuel Consumption

The fuel consumption rate for individual kW ranges are listed in the Specifications section at the front of this manual. Table 3 shows standard fuel consumption rates based on 4 different kW ranges.

Table 3. Standard Fuel Consumption Rates

Load (kW) BTU / Hr LP Gal

/ Hr

5 110,000 1.2 110 1.1

10 176,400 2 156 1.6

15 231,800 2.5 220 2.2

20 267,100 2.8 262 2.6

NG FT3 / Hr NG Therms

/ Hr

Page 16

Note: Typical fuel consumption based on a Generator 100% loaded.

Page 19

GENERAL INFORMATION

FUEL SELECTION LEVER -

“OUT” POSITION FOR LIQUID PROPANE (VAPOR) FUEL

PART 1

Section 1.3

Preparation Before Use

RECONFIGURING THE FUEL SYSTEM

8kW, 410cc Engine

To reconfigure the fuel system from NG to LP, follow these steps (Figure 9):

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. Take 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 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.

10, 13, 14, 15, 16, 17 and 20kw, V-twin Engines

To reconfigure the fuel system from NG to LP, follow these steps:

1. Open the roof.

2. For 10kW units: Loosen clamp and slide back the air inlet hose.

•Slide fuel selector on carburetor out towards the back of the

enclosure (Figures 10 and 11).

•Return the inlet hose and tighten clamp securely.

For 13, 14, 15, 16, 17 and 20kW units: remove the air

cleaner cover.

•Slide the selector lever towards the back of the enclosure

(Figures 12 and 13).

•Re-install the air cleaner cover and tighten the two thumb

screws.

FUEL SELECTION LEVER -

“IN” POSITION FOR NATURAL GAS

Note: Use an approved pipe sealant or joint compound on all threaded fittings to reduce the possibility of leakage.

Figure 10. 10kW, GT-530 (Inlet Hose Slid Back)

Figure 9. Fuel Selector

Figure 11. 10kW, GT-530 (Inlet Hose Slid Back)

Page 17

Page 20

Section 1.3

Preparation Before Use

3. Close the roof.

4. Reverse the procedure to convert back to natural gas.

FUEL SELECTION LEVER -

“IN” POSITION FOR NATURAL GAS

Figure 12. 13, 14, 15, 16, 17, & 20kW,

GT-990/GT-999 (Airbox Cover Removed)

PART 1

GENERAL INFORMATION

FUEL SELECTION LEVER -

“OUT” POSITION FOR LIQUID PROPANE (VAPOR) FUEL

Figure 13. 13, 14, 15, 16, 17, & 20kW,

GT-990/GT-999 (Airbox Cover Removed)

Page 18

Page 21

GENERAL INFORMATION

PART 1

Section 1.4

Measuring Electricity

METERS

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

•To measure AC voltage, use an AC voltmeter.

•To measure DC voltage, use a DC voltmeter.

•Use a frequency meter to measure AC frequency In “Her tz”

or “cycles per second”.

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

THE VOM

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

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

“Digital” VOM’s (Figure 14) 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 V OL T A GE

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

1. Always read the generator’s AC output voltage at the unit’s rated operating speed and AC frequency.

2. The generator’s rated AC output voltage is 250 to 254 VAC and is not adjustable.

3. Only an AC voltmeter may be used to measure AC voltage. DO NOT USE A DC VOLTMETER FOR THIS PURPOSE.

Generators produce high and dangerous voltages.



Contact with high voltage terminals will result in dangerous and possibly lethal electrical shock.

MEASURING DC VOL T A GE

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.

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 (-).

Figure 14. Digital VOM

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 Rotors must run at 1800 rpm to deliver a 60 Hertz output.

Page 19

Page 22

Section 1.4

Measuring Electricity

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 17 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.

1.00 A

BATTERY

RELAY

Figure 15. Clamp-On Ammeter

Figure 16. 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.

Figure 17. A VOM as an In-line Amp 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, or checking a wire for an open or grounded condition.

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

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

•A “shor t-to-ground” condition in any Stator or Rotor winding, or a short to ground on a specific control wire.

•Shorting together of any two parallel Stator windings.

•Shorting together of any two isolated Stator windings.

•An open condition in any Stator or Rotor winding, or an open

in a control wire.

Page 20

Page 23

GENERAL INFORMATION

PART 1

Section 1.4

Measuring Electricity

Component testing may require a specific resistance value or a test for INFINITY or CONTINUITY. Infinity is an OPEN condition between two electrical points, which would read as no resistance, or OL (Open Line) on a VOM. Continuity is a closed condition between two electrical points, which would be indicated as very low resistance (000.000) 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 6.241x1018 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 Electromotive Force (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 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.

VOLTS

(E)

AMPS

(I)

OHMS

(R)

Conductor of a Circuit

OHM - Unit measuring resistance

or opposition to flow

AMPERE - Unit measuring rate of

current flow (number of electrons past a given point)

VOLT - Unit measuring force or

difference in potential causing current flow

Figure 18. Electrical Units

Figure 19. 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

Page 21

Page 24

Section 1.5

Testing, Cleaning and Drying

PART 1

GENERAL INFORMATION

VISUAL INSPECTION

When it becomes necessary to test or troubleshoot an alternator, 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:

•Burned or broken wires, broken wire connectors, damaged mounting brackets, etc.

•Look for loose or frayed wiring insulation, loose or dir ty connections.

•Check that all wiring is well clear of rotating par ts.

•Verify that the Generators voltage output matches Utility

voltage.

•Look for foreign objects, loose nuts, bolts and other fasteners.

•Clean the area around the Generator. Clear away paper, leaves, snow, and other objects that might blow against the Generator and obstruct its air openings.

•Insulation Resistance

The insulation resistances of stator and rotor windings are a measurement of the integrity of the insulating material that separates the electrical windings from the Generator steel core. This resistance can degrade over time or due to such contaminates as dust, dirt, oil, grease and especially moisture. In most cases, failures of stator and rotor windings are due to a break down in the insulation. In many cases, a low insulation resistance is caused by moisture that collects while the Generator is shut down. When problems are caused by moisture buildup on the windings, this can usually be corrected by drying the windings. Cleaning and drying the windings can usually eliminate dirt and moisture that has built up in the Generator windings.

THE MEGOHMMETER

Introduction

A Megohmmeter often called a “megger”, consists of a meter calibrated in megohms and a power supply. Set the “megger” to a voltage setting of 500 volts when testing stators and rotors.

•DO NOT EXCEED 500 VOLTS

•DO NOT APPLY VOLTAGE LONGER THAN 1 SECOND

•FOLLOW THE “MEGGER” MANUFACTURERS INSTRUCTIONS

CAREFULLY

Testing Stator Insulation

CONFIGURATION A

PIN #

CLOSEST TO

BEARING

STATOR

2 6

TO C1 SEE TABLE FOR PINOUT

33 44

44 11

6 2

4 0

44 11

6 2

4 0

CONFIGURATION B

44 11

6 2

4 0

PIN #

5 6

4 0

Figure 20. Stator Output Leads

Isolate all stator leads (Figure 20) and connect all the stator leads together.

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

To calculate the MINIMUM acceptable megger readings use the following formula:

MINIMUM INSULATION RESISTANCE = (in “Megohms”)

GENERA T OR RA TED V OLTS

__________________________

1000

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

120

+ 1 = 1.12 megohms

1000

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 in “Stator Insulation Tests.”

Testing Rotor Insulation

Apply a voltage of 500 volts across the rotor positive slip ring (nearest the rotor bearing), and a clean frame ground (i.e. the rotor shaft).

Warning: Megger HIGH voltages could cause damage



to other components on the Generator. Take the proper precautions before testing.

Page 22

•DO NOT EXCEED 500 VOLTS

•DO NOT APPLY VOLTAGE LONGER THAN 1 SECOND

•FOLLOW THE “MEGGER” MANUFACTURERS INSTRUCTIONS

CAREFULLY

ROTOR MINIMUM INSULATION RESISTANCE:

1.5 megohms

Page 25

GENERAL INFORMATION

PART 1

CLEANING THE GENERAT OR

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).

Do not use sprayed water to clean the Generator. Some



of the water will remain on the Generator windings and terminals and may cause very serious problems.

DRYING THE GENERAT OR

The procedure for drying an alternator is as follows:

1. Open the Generator main circuit breaker.

Generator should have no electrical loads applied while



drying.

Section 1.5

Testing, Cleaning and Drying

2. Disconnect all wires in a manner that allows the alternator to be completed disconnected.

3. Provide an external source to blow warm, dry air through the Generator interior (around the rotor and stator windings.

Do not exceed 185º F (85ºC).



4. Re-connect stator lead.

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

6. Shutdown the Generator and repeat the insulation resistance tests.

Page 23

Page 26

NOTES

PART 1

GENERAL INFORMATION

Page 24

Page 27

GENERAL INFORMATION

PART 1

Section 1.6

Operating Instructions

CONTROL PANEL

Figure 21. Nexus Controller Panel

With the switch set to AUTO, the engine may crank



AUTO-OFF-MANUAL Switch

AUTO Position – Selecting this switch activates fully automatic system operation. It also allows the unit to automatically start and exercise the engine every seven days with the setting of the exercise timer (see Section 5.2 “Setting the Exercise Timer”).

OFF Position – This switch position shuts down the engine. This position also prevents automatic operation.

MANUAL Position – Set the switch to MANUAL to crank and start the engine. Transfer to standby power will not occur unless there is a Utility failure.

7.5 Amp Fuse

This fuse protects the controller as well as the DC components against overload. If the fuse element has melted open due to an overload, engine cranking or running will not be possible. Should a fuse replacement become necessary, use only an identical 7.5 amp replacement fuse.

and start at any time without warning. Such automatic starting occurs when Utility power source voltage droops below a preset level or during the normal exercise cycle. To prevent possible injury that might be caused by such sudden starts, always set the switch to OFF and remove the fuse before working on or around the Generator or transfer switch. Then, place a “DO NOT OPERATE” tag on the Generator panel and on the transfer switch.

USER INTERFACE

Exercise Time

The Generator is equipped with an internal exercise timer. Once set, the Generator will start and exercise every seven days, on the day of the week and 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 is lost. See Section 5.2 for information on setting the exercise time.

Note: The exerciser will only work with the AUTO-OFFMANUAL switch in the AUTO position.

Activation Wizard

When battery power is applied to the Generator during the installation process, the controller will light up. However, if the Generator is not activated it will NOT automatically run in the event of a power outage. Activating the Generator is a simple one-time process that is guided by the controller screen prompts. Once the product is activated, the controller will not prompt you again, even if the battery is disconnected. See Section 5.2 for the activation wizard procedure.

Installation Wizard

During the initial setup of the controller, an interconnection selftest will load on the screen.

Upon power up, this controller will go through a system self test which will check for the presence of Utility voltage on the DC circuits. If the installer mistakenly connects the AC Utility sense wires onto the DC terminal block the controller may be rendered inoperable. If the self-test failed and detected Utility voltage on the DC circuits, the controller will display a warning message and lock out the Generator, preventing damage to the controller. Power to the controller must be cycled for this warning message to clear. Utility voltage on N1 and N2 must be present inside the Generator control panel for the self-test to begin. Each time power to the controller is cycled the self-test will check for correct wiring.

Damage caused by improper wiring of the control wires



is not warrantable!

Time and Date

After the successful completion of the installation wizard, the controller will prompt the user to set the minimum settings to operate. The prompts are as follows: current date, current time, exercise time, and exercise day. These settings may be changed at any time utilizing the “EDIT” menu. See Section 4.1 for “Menu Navigation”

Note: Maintenance interval initialization will take place when the exercise time is set.

If the 12-volt battery or fuse is removed, the Installation Wizard will operate when power has been restored. The only prompts that will follow are the current time and date.

Note: To test the Generator prior to installation, press the

Page 25

Page 28

Section 1.6

Operating Instructions

PART 1

GENERAL INFORMATION

“ENTER” key to avoid setting up the exercise time. This will ensure that when the customer powers up the unit, the controller will prompt the consumer to enter the exercise time.

Low Speed Exercise

On the 17 and 20kW Generators this feature, when enabled, allows the Generator to exercise at 2,400 rpm. Low speed exercise can be disabled from the “EDIT” menu. See Section

4.1 “Menu Navigation”.

Display Interface Menus

The LCD display is as detailed below

•The “Home” page is the default page and will display if no keys are pressed for 30 seconds. This page normally shows the current status and the current time and date. It will also display the highest priority active Alarm and/or Warning along with the backlight flashing when one of these events occurs. In the case of multiple Alarms or Warnings, the controller will only display the first message. To clear an Alarm or Warning, see Section 4.2 “Protection Systems.”

•The display backlight is normally off. If the user presses any key, the backlight will come on automatically and remain on for 30 seconds after the last key is pressed.

•The “Main Menu” page will allow the user to navigate to all other pages or sub-menus by using the Left/Right and Enter keys. Each press of the Escape key takes you back to the previous menu until the main menu is reached. This page displays the following options: HISTORY, STATUS, EDIT, and DEBUG. See Section 4.1 - “Menu System.”

MANUAL OPERATION

Transfer to “Standby” and Manual Startup

To transfer electrical loads to the Generator and to start the Generator manually, the procedure is as follows:

1. On the Generator, set the AUTO-OFF-MANUAL switch to the OFF position.

2. On the Generator, set the main line circuit breaker (MLCB) to the “Open” Position.

3. Locate a means of Utility disconnect and set it to the OFF position.

4. Manually actuate the CONTACTOR to the “Standby” position. See Section 5.1 for specific instructions.

5. On the Generator, set the AUTO-OFF-MANUAL switch to the MANUAL position.

Engine will crank and start!



6. Let the engine warm up and stabilize for a minute or two at no-load. Set the Generators MLCB to the “Closed” position. Generator voltage is available to the transferred electrical loads.

TO SELECT AUTOMATIC OPERATION

The following procedure applies only to those installations which utilize an air-cooled Generator in conjunction with a transfer switch. Residential transfer switches do not have intelligent circuits of their own. PCB logic in the controller controls the automatic operation of the transfer switch and the Generator.

To select automatic operation when a transfer switch is installed along with a home standby Generator, the procedure is as follows.

1. Ensure the CONTACTOR in the transfer switch is in the “Utility” position. If needed, manually actuate the switch contacts to the “Utility” position. See Section 5.1 for specific instructions.

2. Ensure Utility voltage is available to the UTILITY terminals N1 and N2.

3. Actuate the Generator main line circuit breaker (MLCB) to its “Closed” position.

4. Set the Generator AUTO-OFF-MANUAL switch to the AUTO position.

Following the procedure of Steps 1 through 4, a dropout in Utility voltage below a preset level will result in automatic Generator cranking and start-up. Following startup, the transfer switch will actuate to the “Standby” position.

Retransfer Back to “Utility” and Manual Shutdown

To shutdown the Generator and retransfer electrical loads back to the “Utility” position, the procedure is as follows:

1. Set the Generators MLCB to its “Open” position.

2. Allow the Generator to run at no-load for several minutes to cool.

3. Set the Generators AUTO-OFF-MANUAL switch to the OFF position.

4. Locate a means of Utility disconnect and set it to the OFF position.

5. Manually actuate the CONTACTOR to the “Utility” position.

6. Restore Utility voltage to the transfer switch, by the means that was utilized in Step 4.

7. Set the Generator AUTO-OFF-MANUAL switch to AUTO.

With the Generator in AUTO, a dropout in Utility voltage below a preset level will result in automatic Generator cranking and start-up. Following startup, the transfer switch will actuate to the “Standby” position.

Page 26

Page 29

GENERAL INFORMATION

PART 1

Section 1.7

Automatic Operating Parameters

INTRODUCTION

When the Generator is installed in conjunction with a transfer switch, either manual or automatic operation is possible. See Section 5.1 for the manual transfer and engine startup, manual shutdown and re-transfer, and full automatic operation procedure.

UTILITY FAILURE

Initial Conditions

The Generator is in AUTO, ready to run, and the CONTACTOR is in the “Utility” position. When Utility fails (below 65% of nominal), a 10-second line interrupt delay time is star ted. If the Utility is still not present when the timer expires, the engine will crank and start. Once started a five (5) second engine warm-up timer will start.

When the warm-up timer expires the controller will transfer load to the Generator. If Utility voltage is restored (above 75% of nominal) at any time between the initiation of the engine start and when the Generator is ready to accept load, (five 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 CONTACTOR will remain in the “Utility” position.

CRANKING CONDITIONS

The following notes apply during the crank cycle.

1. Starter motor will not engage within 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 energizes, the controller will begin looking for engine rotation. If it does not see an RPM signal within 3 seconds it will shut down and latch out on “RPM Sensor loss”

5. Once the controller sees an RPM signal it will energize the fuel solenoid, drive the throttle open, and continue the crank sequence. The fuel solenoid does not activated earlier because if the engine does not crank, this would potentially fill the engine/exhaust up with fuel. It takes at least 3 seconds to detect cranking on the engine with a magneto RPM measurement. This would result in 3 seconds of fuel being delivered, increasing the chances of a backfire.

6. The starter motor will disengage when speed reaches starter dropout

CRANKING

The controller will cyclic crank the engine 5 times as follows: 16 second crank, 7 second rest, 16 second crank, 7 second rest followed by 3 additional cycles of 7 second cranks followed by 7 second rests.

Choke Operation

•The 990/999cc engines have an electric choke in the air box that is controlled automatically via the controller.

•The 530cc engines have an electric choke on the divider panel air inlet hose, control is done automatically via the controller

•The 410cc engines have a choke behind the air box. Control is done automatically via the controller.

Failure to Start

Failure to start is defined as any of the following occurrences during cranking.

1. Not reaching starter dropout within the specified crank

cycle.

Note: Starter dropout is defined as 4 cycles at 1,000RPM

2. Reaching starter dropout, but then not reaching 2200 rpm

within 15 seconds. After which the controller will go into a rest cycle for 7 seconds, then continue the rest of the crank cycle.

Note: During a rest cycle the start and fuel outputs are deenergized and the magneto output is shorted to ground.

7. If the Generator does not reach 2200 rpm within 15 seconds, re-crank cycle will occur.

8. If the engine stops turning between starter dropout and 2200 RPM the board will go into a rest cycle for 7 seconds then re-crank (if additional crank cycles exist.)

9. Once star ted the Generator will wait for a hold off period before starting to monitor oil pressure and oil temperature. See Section 4.2 “Engine Protective Devices”

10. During a manual crank attempt, if the AUTO-OFF-MANUAL is switched from MANUAL position to OFF, the crank attempt will abort.

11. During automatic crank attempt, if the Utility returns, the cranking cycle does NOT abort, but continues until complete. Once the engine starts, it will run for one minute then shut down.

LOAD TRANSFER PARAMETERS

The transfer of load when the Generator is running is dependent upon the operating mode as follows:

Manual

•No transfer to Standby when Utility is present.

•Transfer to Standby will occur if Utility fails (below 65% of

nominal) for 10 consecutive seconds.

•Transfer back to Utility when Utility returns for 15 consecu-

tive seconds. The engine will continue to run until removed from the Manual mode.

Page 27

Page 30

Section 1.7

Automatic Operating Parameters

Auto

•Transfer to standby will occur if Utility fails (below 65% of nominal) for 10 consecutive seconds.

•A five (5) second engine warm-up timer will initialize.

•Transfer back to the “Utility” position if Utility subsequently

returns.

•Transfer to the “Standby” position if Utility is still not present.

•Transfer back to Utility once Utility returns (above 75% of

nominal) for 15 seconds.

•Transfer back to Utility, if present, if the Generator is shut down for any reason (such as the switch turned to the OFF position or a shutdown alarm 0.

•After transferring back to Utility the engine will shut down, after a one (1) minute cool-down timer expires.

Exercise

•Exercise will not function if the Generator is already running in either Auto or Manual mode.

•During exercise, the controller will only transfer if Utility fails during exercise for 10 seconds, and will follow the steps outlined above for Auto operation.

PART 1

GENERAL INFORMATION

UTILITY RESTORED

The Generator is running, CONTACTOR in “Standby”, running in Utility failure. 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 28

Page 31

GENERAL INFORMATION

PART 1

Section 1.8

General Maintenance

INTRODUCTION

Performing proper maintenance on a Generator will ensure proper function during a Utility failure. Once a Generator has failed, it is already too late. Ensuring the proper oil changes and inspections have been completed at the specified times will help keep the Generator reliable.

MAINTENANCE MESSAGE

When a maintenance period expires, a warning message will be displayed. Pressing the Enter key will cause the alert to reset and will prompt the user to confirm the action. Resetting will clear the alert and reset the maintenance counters for all warnings annunciated. The history log will record the aler t. The maintenance counter will not accumulate without battery voltage. Once restored, a prompt will appear for the user to set the time and date. The new date and time will adjust the maintenance counters accordingly.

Only one alert will appear on the display at any one time. With the acknowledgement of the first alert, the next active alert will be displayed

Message Interval

Table 4. Message Intervals

“Inspect Battery” 1 Year

“Change Oil & Filter” 200 hours or 2 years, 100 hours or

2 years on 20kW models

“Inspect Air Filter” 200 Hours or 2 years

“Change Air Filter” 200 Hours Or 2 years

“Inspect Spark Plugs” 200 Hours or 2 years

“Change spark Plugs” 400 hours or 10 years

Resetting Maintenance Intervals

When a complete maintenance inspection has been completed before a specific alert was generated, it is possible to reset the intervals to prevent future alerts from occurring for maintenance that was just performed. To reset the intervals proceed to Section 4.1 “Menu Navigation” for further information

With the resetting of the intervals, all maintenance counters will start from the current time and date of the Generator.

•SAE 30  Above 32º F

•10W-30  Between 40ºF and -10ºF

•Synthetic 5W-30  10ºF and below

Table 6.

SAE 30

10W-30

Synthetic 5W-30

Any attempt to crank or start the engine without the



recommended oil may result in an engine failure.

AIR FILTER

Air is necessary for successful combustion in the engine. Clean air (almost 100% pure) is critical to engine survival and vital to its performance. There are operational signs when an air filter has become completely plugged. The engine begins to lose power, and fuel consumption increases. Black smoke may blow from the exhaust. Continued operation with a plugged air filter may cause severe damage to the engine.

SPARK PLUGS

Good spark is essential to properly maintaining the engine. Although replacement may not be required, inspection of the plugs during routing maintenance is critical. Always verify that spark plugs are gapped according to the specifications. Improperly gaped spark plugs will effect the operation of the engine.

See Test 57 for diagnosing spark plug related problems.

See “Specifications” for specific spark plug gaps.

Engine Oil

Modern oils play vital functions in protecting the engine. Lubricating oil acts to reduce friction and wear, cool engine parts, seal combustion chambers, clean engine components, and inhibit corrosion. See Table 7 “Service Schedule” for specific inspection items and interval

Engine Oil Recommendations

All oil should meet minimum American Petroleum Institute (API) Service Class SJ, SL or better. Do not use special additives. Select the oil’s viscosity grade according to the expected operating temperature. Refer to Table 6.

VISUAL INSPECTION

During all service intervals, a proper visual inspection must be conducted to ensure proper function, airflow, and to prevent fire hazards.

Air inlet and outlet openings in the Generator compartment must be open and unobstructed for continued proper operation. This includes such obstructions as high grass, weeds, brush, leaves, and snow.

Page 29

Page 32

Section 1.8

General Maintenance

The exhaust from this product gets extremely hot and



remains hot after shutdown. High grass, weeds, brush and leaves must remain clear of the exhaust. Such materials may ignite and burn from the heat of the exhaust system.

Figure 22. Cooling Vent Locations

CORROSION PROTECTION

Periodically wash and wax the enclosure using automotive type products. Frequent washing is recommended in salt water/ coastal areas. Spray engine linkages with a light oil such as WD-40.

PART 1

GENERAL INFORMATION

VALVE CLEARANCE

Proper valve clearance is vital to ensuring longevity of the engine. After the first 6 months of operation, check the engine valve clearance and adjust as necessary. Checking of the engine valve clearance thereafter periodically will increase reliability of the Generator. Refer to Test 63 for Specification

and adjustment procedure.

Some symptoms of an engine with valves in need of adjustment are:

•Hard star ting

•Smoke out of the exhaust

•Rough running

•Lack of horse power

BATTERY

Performing proper battery maintenance at the required intervals will allow for proper starting of the Generator during a power outage. Some common things to look for and check during maintenance are:

•Inspect the battery posts and cables for tightness and corrosion. Tighten and clean as necessary.

•Check the battery fluid level of unsealed batteries and, if necessary, fill with Distilled Water only. Do not use tap water in batteries.

•Have the state of charge and conditions checked. This should be done with an automotive-type battery hydrometer.

Note: See Test 45 for further testing the state of a battery.

Page 30

Page 33

GENERAL INFORMATION

PART 1

General Maintenance

Section 1.8

Table 7. Service Schedule

SYSTEM/COMPONENT PROCEDURE FREQUENCY

X = Action

R = Replace as Necessary

* = Notify Dealer if Repair is

Inspect Change Clean

W = Weekly

M = Monthly

Y = Yearly

Needed.

FUEL

Fuel lines and connections*

X M

LUBRICATION

Oil level

X M or 24 hours of

continuous operation.

Oil

X 2Y or 200 hours

of operation.**

Oil filter

X 2Y or 200 hours

of operation.**

COOLING

Enclosure louvers

X X W

BATTERY

Remove corrosion, ensure dryness

Clean and tighten battery terminals

Check charge state

Electrolyte level

X X M

X R EVERY 6 M

ENGINE AND MOUNTING

Air cleaner

Spark plug(s)

X R 2Y or 200 hours

GENERAL CONDITION

Vibration, Noise, Leakage, Temperature*

X M

COMPLETE TUNE-UP* TO BE COMPLETED BY A DEALER 2Y or 200 hours

* Contact the nearest dealer for assistance if necessary.

** Change oil and filter after first eight (8) hours of operation and then every 200 hours thereafter, or 2 years, whichever occurs first.

Change sooner when operating under a heavy load or in a dusty or dirty environment or in high ambient temperatures.

Page 31

Page 34

Section 1.9

Wireless Remote

PART 1

GENERAL INFORMATION

WIRELESS MONITOR

A small wireless device (about the size of a credit card) provides a basic approach to wireless monitoring; however, the device only provides three basic alerts.

Figure 23. Nexus™ Wireless Monitor

The green LED (Generator OK) indicates that either:

•The Auto/Off/Manual switch on the generator is set to the Auto position, no alarms are present, and the generator is ready to start and run or is running.

Or:

•The Auto/Off/Manual switch on the generator is set to the Manual position, the engine is running and no alarms are active.

When active, the green LED will flash once every 10 seconds.

The yellow LED (Maintenance Needed) indicates that either a GENERATOR WARNING is present or generator maintenance is required. The generator will not be prevented from running when the yellow LED is on. When active, the yellow LED will flash once every two (2) seconds.

The red LED (Contact Dealer) indicates any one of the following conditions:

•The Auto/Off/Manual switch on the generator is in the Off position.

•The generator has not been registered

•A generator alarm is present.

•The controller has been powered up, but the star t up wizard

procedure has not been completed.

If a generator alarm is present the generator will not start and run in the event of a utility loss, or will be automatically shut down if the engine is already running. When active, the red LED will flash once every second.

The internal buzzer will sound once every 30 seconds when the red LED is on. The buzzer can be silenced by briefly pressing and releasing the Pair/Reset button; the buzzer will pulse twice to indicate it has been silenced. The buzzer will not reactivate until a new alarm has been detected.

The wireless monitor display unit updates the status of its LED's every 30 to 60 seconds. To conserve power and extend battery life, the LED's are not lit continuously: instead they are briefly flashed as indicated above.

WIRELESS BASIC TROUBLESHOOTING.

Pairing the Generator Transceiver with the Display Unit

1. See figure 11 for the location of the “Pair/Reset” button on the display unit.

Place the display unit against the generator transceiver as

shown in figure 10, then immediately press and hold the “Pair/Reset” button on the display unit

2. Once the yellow LED begins flashing (after about three seconds), indicating the modules are in pairing mode, release the “Pair/Reset” button on the display unit and move the display unit away from the generator transceiver.

3. The Yellow LED will continue to flash during the pairing process.

4. Once the two modules have successfully paired up the yellow LED will stop flashing and the green LED will begin flashing.

5. Press and release the Pair/Reset button to complete the pairing process. At this time the green LED will stop flashing and the display unit will enter its normal mode of operation.

Note: If the Auto/Off/Manual switch is still in the off mode the red LED will begin to flash to indicate the generator is in alarm mode. Do not confuse this flashing red LED with the “failure to pair” described below.

Figure 24. Place the Display Unit Against the Generator

Transceiver

NOTE: The magnets in the display unit activate a magnetic reed switch in the generator transceiver in step 21. The relative positioning of the two units needs to be as shown in Figure 10 to activate the magnetic reed switch.

Page 32

Page 35

GENERAL INFORMATION

Figure 25. Location of Pair/Reset Button

6. Proceed with the “Re-Assemble the Generator” section

7. If the two modules fail to pair up within 30 seconds, the yellow LED will stop flashing and the red LED will begin to flash. If this happens proceed as follows:

•Press and release the Pair/Reset button to stop the red LED

from flashing.

•Check that good non-rechargeable AAA 1.5V batteries are

installed.

•Check the wiring to make sure all the plugs are fully inser t-

ed.

•Repeat the pairing process from step 21A.

Results

1. If the link is established, discontinue troubleshooting.

2. If the link continues to fail, replace the wireless remote and transmitter.

PART 1

WIRELESS ADVANCED MODULE

Section 1.9

Wireless Remote

feet but this will be reduced if the signal has to go through walls, floors, etc.

NOTE: Some building materials may completely block the passage of the signal. For example: steel beams, metal siding, foil radiant barrier insulation.

The display is intended to show the status of the generator and warn you if the system is in an alarm state. It also provides the following additional functions:

•An independent (of the generator Alarm Log) time/date stamped history of Generator events such as starting and stopping.

•Allows remote star ting and stopping of the generator.

•Facility to set an exercise time and day from the display.

•A separate battery backed clock (with date) which is

synchronized to the generator clock. If power is removed from the generator, the time and date will automatically be restored from this clock.

•Ability to add extra displays.

•Graphing capability.

WIRELESS ADVANCED FEATURES

One of the most commonly used features on the device is the ability to test the functions of the generator. The “TEST” menu provides the option to remotely start, start and transfer, and stop the generator. This feature only works when the AUTO-OFF-MANUAL switch is set to AUTO and Utility voltage is available.

Note: The remote cannot disable or prevent the Generator from running; the only method to disable the generator is by cycling the AUTO-OFF-MANUAL switch to the OFF position.

Some operational rules apply when using the “TEST” feature and are not due to product failure:

•The Generator can only be shutdown if it was star ted via the remote. It will not respond to the command if running in a Utility failure.

•When the command has been given for a star t and transfer to occur the Generator will stay running until the “STOP” command has been given. The generator will then run for a 1 minute cool down period.

Figure 26. Wireless Advanced Module

The wireless display system consists of two identical radio transceivers, one mounted near the Generator and the other (the one with the display), should be in a convenient viewing location. The system has a “line of sight” range of about 300

WIRELESS ADV ANCED TROUBLESHOOTING.

Resynchronizing the Radio After Battery Disconnection or In the Event of Loss of Communication

If the battery is ever disconnected from the generator, the radio system will stop working and WILL NOT AUTOMATICALLY resynchronize. To resynchronize the system, follow the steps (similar to installation) shown below:

1. Ensure the display unit has working batteries fitted into it.

2. Take the display unit to the generator and turn the display

unit off using the slide switch on the side of the unit.

3. Open the generator lid and turn the generator Auto/Off/

Manual switch to the “Off” position.

Page 33

Page 36

Section 1.9

Wireless Remote

4. Remove the large enclosure panel from the front of the enclosure.

5. Locate the radio connector under the generator display panel. It is the closest one to you as you are facing the generator; it has a white connector with gray cable going to it. It has a locking tab that needs to be squeezed to remove it. Remove the connector by squeezing the tab and pulling the connector down. As the locking mechanism is a tight fit, you may need pliers to help release it.

6. Turn on the display unit and go to the RADIO menu.

7. Select “RESET RADIO” and IMMEDIATELY (within 5 seconds) put the connector back into the controller (that you removed in step 5E).

8. The display unit will start searching for the generator. Up to one minute will pass while the remote unit and generator synchronize. Once the generator is found, the radio link has been re-established and the settings will be remembered.

9. Re-fit the front enclosure panel and close the lid.

PART 1

GENERAL INFORMATION

10. Turn the Auto/Off/Manual switch to the Auto position.

11. Return the display unit to its original location and re-connect it to the wall transformer. Turn it off and back on again (this is just to get it out of sleep mode which it may have entered on battery power).

Results

1. If the link is established, discontinue troubleshooting.

2. If the link fails to establish, repeat Steps 5-8 using a different channel.

3. If the link continues to fail, replace the wireless remote and transmitter.

Page 34

Page 37

GENERAL INFORMATION

To get to the Main Menu from any other display, press the “Esc” key one or more times. The Main Menu is shown in Figure 27. There are four sub-menus, each with its own set of sub-menus. The menu system diagram is shown in Figure 37.

There are four selection and navigation keys below the display. The “Escape” key will cause the display to move back toward the main menu. The “Enter” key is used to activate a menu or accept a value when it is changed. The UP and DOWN triangle keys perform a number of different functions depending on which screen of a menu you are in: with them you can move the flashing curser to the next choice (the menu to be selected will flash on and off); they will act as the left and right arrows to move between the various Edit menus; In an Edit menu they will increase or decrease a value or change the choice (i.e. from Yes to No). See Figure 37 for the Basic Menu System Diagram.

PART 1

Section 1.10

Nexus Control Panel Menu System Navigation

History

Alarm Log

Figure 29. History Menu

Run Log

1 09/15/10 04:55:22

Under Voltage

Figure 30. Alarm Log Display.

Use the up and down keys to move from the most recent Alarm (1) to the oldest (50).

1 09/15/10 04:55:22

Figure 27. Nexus Display and Navigation Buttons

MAIN MENU

There are 4 selections in the Main Menu: History, Status, Edit, and Debug.

Figure 28. Nexus Display Main Menu

History

The History Menu will display two history logs: Alarm Log and Run Log.

•Alarm Log: displays the last 50 alarm conditions. They are in date time order, numbered from 1 to 50; 1 is the most recent. Use the (up triangle image) and the (down triangle image) to move from alarm to alarm. Each alarm lists the Date, Time of trigger, and the description of the alarm.

•The Run Log will display the last 50 Run events. It will display the date and time as well as a brief description of the event; for instance Running – Utility Lost; Stopped – Auto.

Stopped

Figure 31. Run Log Display.

Use the up and down keys to move from the most recent Run event (1) to the oldest (50).

Status

The Status Menu will display four choices: State, Display, Command, and Versions. Use the up and down triangle keys to move the

•State will display the current state of the panel along with the current date, time and day. See Figure 37 for the complete list of possible Status messages which will be displayed.

•Command will display the current command. See Figure 37 for the list of possible commands which will be displayed.

•Versions will display the version of Software and Hardware of the panel.

•Display will provide up to five generator parameters: Run Hours, RPM, Hz, Battery, and Hours Under Load (if enabled).

- Run Hours will display the total number of hours the generator has run (in 0.0 Hours format)

- RPM will display the Engine Speed (in RPM)

- Hz will display the generator output frequency (in 0.0 Hz format)

- Battery will display the battery voltage (i.e. 12.9)

- Hours Under Load will provide the total number of hours the unit has actually provided power.

Page 35

Page 38

Section 1.10

Nexus Control Panel Menu System Navigation

STATUS: State Display

Command Versions

Figure 32. Status Menu

Display: Run Hours

RPM Hz Battery

Figure 33. Display Menu

PART 1

•TEST Output provides a way to see the status or the output relays the control panel uses to make things happen (like crank and run and transfer). See Table 8 for the list of output channels. Each channel represents a relay with a character of either 0 or 1. The 0 character represents a relay that is de-energized (OFF); a 1 represents a relay that is energized (ON). The outputs screen is a handy way to tell if the control is telling the generator to start, or transfer, etc.

•Display provides two flashing bars that test the display LEDs. As the bars flash on and off you can readily tell if the display has a bad area; if an area does not turn on it means those LEDs are not working. The control panel would require replacement to correct a bad display.

•QT-Test is only available on the 17-20kW units. It provides a way to test the Quiet Test mode of the generator. When tested the generator will run at a lower RPM during the test. Note that for the unit to perform an actual weekly Quiet Test Exercise, it must be enabled in the Exercise Time editing menu.

GENERAL INFORMATION

Edit

Provides the means to edit five of the operating parameters of the unit: Exercise Time, Current Time, Frequency, Language, Startup Delay, and Reset Maintenance. To access the editing screens go to the Edit menu and press the “Enter” button. One of the above menus will appear. Use the UP and DOWN triangle buttons to move from menu to menu. When you are in the menu you want to change press the “Enter” button. Then use the UP and DOWN triangle buttons to change the value. When you have reached the value you want press the “Enter” button. If you want to get out of a choice without changing it simply press the “Esc” button.

•Exercise Time will go through 4 selections: Quiet Test Mode (Yes/No), Select Hour, Select Minute, and Select Day. When you are through the unit will be programmed to perform a weekly exercise.

•Current Time will go through 5 selections: Select Hour, Select Minute, Select Month, Select Date, Select Year. The current time must be set to enable the exercise and maintenance functions of the panel.

•Frequency is not enabled at this time.

•Language provides three choices; English, Francais, and

Espanol.

•Star tup Delay provides a way to change the time delay between when Utility fails and when the Generator starts and transfers. It is adjustable from 10 to 30 seconds.

•Reset Maintenance will reset the Maintenance warning clock.

Debug

Provides four test tools integral to the control panel: Inputs, Outputs, Display, and QT-Test.

•TEST Inputs provides a way to see the status of the 8 input channels that the control panel monitors. See Table 8 for the list of inputs the control panel monitors. Each input represents an open or closed set of contacts, and will display either a 0 or 1 character. The 0 character represents an open contact; a 1 character represents a closed contact. The Inputs screen is a handy way to tell if the control is seeing a valid input from a particular source.

TEST: Inputs Outputs

Display QT-Test

Figure 34. Debug Menu

INPUTS: Utility 240

0 1 0 0 0 0 1 0

Figure 35. Test Inputs Display

Inputs are numbered from left to right (1-8)

0 indicates an Input is OFF

1 indicates an Input is ON

For instance, in Figure 35 Inputs 2 and 7 are ON (Low Oil Pressure and the Auto switch).

This indicates the unit is shut down and in Automatic.

OUTPUTS: Gen 0

0 0 0 0 0 0 0 0

Figure 36. Test Outputs Display

Outputs are numbered from left to right (1-8)

0 indicates the Output is OFF

1 indicates the Output is ON

For instance, in Figure 36 there are no Outputs ON which indicates the unit is shut down.

Page 36

Page 39

GENERAL INFORMATION

PART 1

Table 8. Digital Inputs and Outputs

Position Digital Inputs Digital Outputs

1 Not Used Not Used

2 Low Oil Pressure Not Used

3 High Temperature Not Used

4 Low Fuel Pressure Battery Charger Relay

5 Wiring Error Detect Ignition

6 Not Used Starter

7 Auto Fuel

8 Manual Transfer

Section 1.10

Nexus Control Panel Menu System Navigation

“ESC, UP, UP ESC, DOWN, UP, ESC, UP, UP, ENTER”

HISTORY STATUS

RUN LOGALARM LOG

Press the “ESCAPE” key

ESC

to jump back up through the menu levels.

Use the “+/-” key

+ / -

to navigate through the menu.

Use the “ENTER” key

ENTER

to select items or enter data.

The possible Status messages of the display are as follows:

• Switched Off/Time & Date

• Ready to Run/Time & Date

• Utility Loss Delay/Pausing for X Seconds

• Cranking/Attempt # X

• Running in Exercise/Time & Date

• Running/Cooling Down

• Running - Warning/Warning Message

• Running - Alarm/Alarm Message

• Stopped - Alarm/Alarm Message

• Stopped - Warning/Warning Message

• Cranking/Pausing for X Seconds

• Running/Time & Date

• Running/Warming Up

• Cranking - Warning/Warning Message

• Cranking - Alarm/Alarm Message

PASSWORD

ESC

Password is entered on this page.

COMMANDSTAT E VERSIONSDISPLAY

ESC

ENGINE

HOURS

ENGINE

RPM

GENERATOR FREQUENCY

BATTERY VOLTA GE

The possible commands on Line 2 of the display are as follows:

• Switched Off

• Running Manually

• Stopped in Auto Mode

• Running - Utility Lost

• Running in Exercise

• Running from Radio

NOTE: SOME VERSIONS MAY HAVE SLIGHTLY DIFFERENT PARAMETERS.

ESC

MAIN MENU

SOFTWARE HARDWARE

IF APPLICABLE

ESC

EDIT

RESET

MAINTENANCE

EXERCISE

TIME

CURRENT

TIME

FREQUENCY

LANGUAGE

START-UP

DELAY

ESC

INPUTS OUTPUTS DISPLAYS

EDIT WITH

PASSWORD

START-UP

DELAY

LANGUAGE

FREQUENCY

CURRENT

TIME

EXERCISE

TIME

ESC

MAINTENANCE

CALIBRATE

RESET

REMOTE

START

VOLTS

DEBUG

ESC

QT TEST

If so equipped

Figure 37. Menu System Diagram

Page 37

Page 40

Section 1.11

General Troubleshooting Guidelines

PART 1

GENERAL INFORMATION

INTRODUCTION

This section familiarizes the service technician with the manufacturer recommended procedures for the testing and evaluation of various problems that can occur on the standby generators with air-cooled engines. It is highly recommended that you read these introductory tips before you attempt to troubleshoot any of the three main generator components: AC Generator, Air Cooled Engine, Transfer Switch. The Troubleshooting Flow Charts provide the simplest, quickest, systematic means to troubleshoot the typical problems that might occur during the lifetime of the unit. If you use the flow charts and perform the indicated tests, you will be able to identify the faulty component, which can then be repaired or replaced as necessary.

The test procedures in each section do require a basic knowledge of electricity and electrical safety, hand tool skills, and use of Volt-Ohm-Meters.

RECOMMENDED TOOLS

In addition to the normal hand tools required, some test procedures may require the use of specialized test equipment. At a minimum you must have a meter that measures AC voltage and frequency, DC voltage and current, and has the ability to record Minimum / Maximum values (digital multi meters [DMM] are recommended); standard meter test leads, a set of piercing probe leads , and a set of pin probe leads for the AMP connector pins. The manufacturer carries a set of acceptable piercing probes (PN 0G7172), or other suppliers piercing probes may be used. Fluke provides a high quality piercing probe, PN AC89, which is highly recommended. The manufacturer also carries a set of flexible pin leads for use with the AMP connector plugs (PN 0J09460SRV).

For engine troubleshooting you will need a good manometer which measures low pressure in Inches of Water Column (IN W.C or IN H20). An ignition spark tester is also a handy tool to have when working with air-cooled engines.

Testing and troubleshooting methods covered in each section are not exhaustive. No attempt has been made to discuss, evaluate and advise the home standby service trade of all conceivable ways in which service and trouble diagnosis must be performed. 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 products safety, and will not cause damage to any connectors or components.

TROUBLESHOOTING REMINDERS AND TIPS

The most important step in troubleshooting is identifying the actual problem. Use the History capability of the Nexus panel to help you identify what the panel is seeing. Use the Alarm Log to view the faults that caused the Warning or Alarm Shutdown. The date-time stamp provides the date and time (to the second) that the alarm event occurred. If there are several alarms that all have the same date-time stamps, go to the first in the series of alarms for that time. Some failures can cause a cascading series of faults to occur, one right after the other. Compare the Alarm Log and the Run Log to each other to see the operational sequence of events.

For instance: If the unit shut down on ALARM - Low Oil Pressure, look to see what time it started. If it star ted at 8/20/10 14:27:30 (2:27 pm), and shut down on low oil pressure on 8/30/10 10:15:22 (10:15 am), then the most likely cause of the loss of oil pressure was low oil level. The unit ran, providing power, for 10 days straight (approximately 234 hours). This would be validated by simply checking the oil level of the unit. These are air-cooled 4 cycle engines and will use oil while running. If run for extended periods of time (several weeks for instance) they will require periodic shut-down to check oil level and do a general inspection. Just think of leaving your lawn mower running at full RPM for several weeks; what would it do?

The next step is to determine the applicable flow chart to use to help diagnose the problem. Use the flow chart index for the part of the generator you are working with. If it is problem with voltage, use Section 2 – AC Generators; for engine problems use Section 4 – Engine/DC Control; for a problem with the transfer switch, use Section 3 – Transfer Switch. The index for each will help you clarify the problem and the flow chart to use. In each flow chart start at the top and use the test indicated to verify whether a component or control item is working properly or not. At the end of each test follow the “good” or “bad” arrows and perform the next test.

It is always good practice to continue to ask questions during the troubleshooting process. When evaluating a problem, these questions may help identify the problem quicker.

•What is it doing? (low voltage; not cranking; not transferring; etc)

•What should it do? (run and start; transfer; shutdown; etc)

•Does the same thing happen each time?

•When is it happening?

•What could or would cause this?

•What type of test will either prove or disprove the cause of

the fault?

IMPORTANT NOTE CONCERNING

CONNECTORS

A number of the tests require the use of a volt-meter and a set of wire piercing probes. When using the piercing probes make sure you use some liquid tape or silicone to coat the insulation where you pierced it; this will keep moisture out and prevent long term corrosion.

It is very easy to damage the female pins in the connectors on the control panel (AMP connectors) and the C1 connector (Molex connector) which goes to the alternator can.

DO NOT ATTEMPT TO PUSH PROBE TIPS INTO THE FEMALE PINS OF ANY AMP or MOLEX CONNECTORS; doing so will damage the female pin which will create another problem. Use the piercing probes on the correct wire to check for the appropriate voltages ; or use the flexible pin leads, available from the manufacturer (PN 0J09460SRV) to work with the AMP connector plugs.

Page 38

Page 41

PART 2

AC GENERATORS

Air-cooled, Automatic

Standby Generators

TABLE OF CONTENTS

SECTION TITLE PAGE

2.1 Description and Components 40

2.2 Operational Analysis 42

2.3 Troubleshooting Flow Charts 44

2.4 Diagnostic Tests 47

Section 2.1 – Description and Components

Introduction .......................................................... 40

Engine-Generator Drive System ............................. 40

Alternator Assembly ............................................. 40

Other AC Generator Components .......................... 40

Section 2.2 – Operational Analysis .................................... 42

Rotor Residual Magnetism .................................... 42

Field Boost ........................................................... 42

Operation .............................................................. 42

Section 2.3 – Troubleshooting Flowcharts ......................... 44

Introduction .......................................................... 44

Problem 1 – Generator Shuts Down

for Under-voltage .............................. 44

Problem 2 – Generator Shuts Down

for High Voltage ................................ 45

Problem 3 – Voltage and Frequency Drop Excessively When Loads Are Applied . 46

....................... 40

Section 2.4 – Diagnostic Tests .......................................... 47

Introduction .......................................................... 47

Safety ................................................................... 47

AC Troubleshooting............................................... 47

Test 1 – Check AC Output Voltage ......................... 47

Test 3 – Calibrate Voltage ...................................... 48

Test 4 – Fixed Excitation Test/

Rotor Amp Draw Test ............................... 48

Test 5 – Test Sensing CircuitWires 11 and 44 ........ 51

Test 6 – Test Excitation WindingCircuit 2 and 6 ...... 52

Test 7 – Test the Stator with a VOM ....................... 52

Test 8 – Resistance Check of Rotor Circuit ............ 54

Test 9 – Check Brushes and Slip Rings ................. 54

Test 10 – Test Rotor Assembly .............................. 55

Test 11 – Check AC Output Frequency ................... 55

Test 12 – Check Stepper Motor Control ................. 56

Test 14 – Check Voltage and

Frequency under Load ........................... 57

Test 15 – Check for an Overload Condition ............ 57

Test 16 – Check Engine Condition ......................... 57

Page 39

Page 42

Section 2.1

SLIP RINGS

BEARING

Description and Components

PART 2

AC GENERATORS

INTRODUCTION

The alternator contained within the Generator is a revolving field (rotor) type with a stationary armature (stator), and excitation to the field provided through brushes and slip rings (direct excitation). The Generator may be used to supply electrical power for the operation of 120 and/or 240 VAC, 1-phase, 60 Hz, AC loads.

ENGINE-GENERATOR DRIVE SYSTEM

The air-cooled engine is directly coupled to the rotor internally. Both the engine and the rotor operate at 3600 rpm to provide a 60 HZ AC output.

ALTERNATOR ASSEMBLY

The standard alternator consists of three basic components; a rotor, stator, and brush assembly. The rotor assembly provides the magnetic field which will induce a voltage into the stator assembly. The brush assembly provides the electrical connection to the rotor, which allows for excitation voltage and current to create the needed magnetic field.

Rotor

Operating the 2-pole rotor at 3600 rpm will supply a 60 HZ AC frequency. The term “2-pole” means the rotor has a single north magnetic pole and a single south magnetic pole. Held in place with a single through bolt, the tapered rotor shaft mounts to the tapered crankshaft of the engine. As the rotor rotates its lines of magnetic flux cut across the stator assembly windings and induces a voltage into the stator windings. The rotor shaft has a positive and negative slip ring, with the positive slip ring nearest the rear-bearing carrier. The bearing is pressed onto the end of the rotor shaft.

CONFIGURATION A

PIN #

CLOSEST TO

BEARING

STATOR

2 6

TO C1 SEE TABLE FOR PINOUT

33 44

44 11

6 2

4 0

44 11

6 2

4 0

CONFIGURATION B

44 11

6 2

4 0

PIN #

5 6

4 0

Figure 39. Stator Output Leads

Brush Holder and Brushes

Attached to the rear-bearing carrier, the brush holder and brushes allow for the electrical connection to the rotor. Positive and negative brushes 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 also connects to the frame ground. The rotor windings receive rectified and regulated excitation current (DC) through Wire 4, as well as current from a field boost circuit. The current flow creates a magnetic field around the rotor having a flux concentration that is proportional to the amount of current flow.

Figure 38. Rotor

Stator

The stator houses a dual power winding and an excitation winding. Coming from the stator there are Eight (8) stator leads as shown in Figure 39.

An adapter molded into the engine block and a rear-bearing carrier support the stator can. Four stator bolts connect the rear bearing carrier and the stator can to the engine.

Page 40

Figure 40. Brush Holder and Brushes

OTHER AC GENERATOR COMPONENTS

Located within the Generator control panel enclosure are the Nexus controller, connection points, SCR, and Main Line Circuit Breaker (MLCB).

Page 43

AC GENERATORS

PART 2

Section 2.1

Description and Components

Voltage Regulator

The Automatic Voltage Regulator (AVR) is an integral component of the main controller. The AVR receives unregulated AC output voltage from the stator excitation winding (DPE) through Wires 2 and 6. The AVR rectifies the AC voltage, and regulates it based on the sensed voltage output of the stator. The regulated DC excitation voltage (current) is then delivered to the rotor windings through Wires 0 and 4, the brushes and slip rings. The voltage regulator senses the AC output voltage of the alternator through Wires 11 and 44.

The control panel provides both Under-voltage and Overvoltage fault protection. During an over or under-voltage fault condition the control panel will shut the unit down and display the applicable Alarm.

•Under-voltage (0H6680A Controller) – If the Generator voltage falls below 60% of rated (144V for a 240V unit) for more than 5 seconds, the generator will shut down and an ALARM will display.

•Under-voltage (0H6680B Controller through Rev B) – If the Generator voltage falls below 85% of rated (204V for a 240V unit) for more than 10 seconds, the generator will shut down and an ALARM will display.

•Under-voltage (0H6680B Controller rev C and greater) – Manual: Cranking – If the starter disengages before a voltage

has developed in the stator, the controller will initiate a shutdown alarm for “under-voltage.”

Running – If the Generator is running and voltage

output has been gone for 10 seconds, the controller

will initiate a shutdown alarm for “under-voltage.” Auto: Cranking – If the starter disengages before a

voltage has developed in the stator, the controller

will shutdown, pause for 15 seconds (countdown

displayed), and re-crank 3 additional times. If after

three crank attempts and the no voltage output

continues, the controller will initiate a shutdown alarm

for “under-voltage.” Running – If the Generator is running and voltage

output has been gone for 10 seconds, the controller

will initiate a shutdown, pause 10 seconds, and

re-crank 3 times additional times. If after three crank

attempts and the no voltage output continues, the

controller will initiate a shutdown for “under-voltage.”

Note: The 3 crank attempts are cumulative. For example, if the unit took two under-voltage re-cranks at startup, it would only allow one additional re-crank for under-voltage.

Main Line Circuit Breaker

The main line circuit breaker protects the Generator against electrical overload. See the “Specifications” section for specific amperage ratings.

11 44

LINE SIDE

E1 E2

Figure 41. Main Line Circuit Breaker

LOAD SIDE

•Over-voltage – If the Generator voltage rises above 110% of rated (264V on a 240V unit) for greater than 3 seconds, or if the Generator voltage rises above 130% of rated (312V on a 240V unit) for greater than 0.2 seconds, the generator will shutdown and an ALARM will display.

Page 41

Page 44

Section 2.2

Operational Analysis

PART 2

AC GENERATORS

ROTOR RESIDUAL MAGNETISM

The Generators revolving field (rotor) provides the magnetic flux required to induce voltage into the stator and excitation windings (DPE). Some “residual” magnetism is always present in the rotor. Although residual magnetism is present it is only sufficient to induce a very low AC output, typically 0 to 6 VAC, and not enough to make the excitation winding (DPE) produce enough voltage for the AVR to operate. In order to make the DPE winding produce enough voltage to turn on and allow the AVR to operate, a Field Boost (flash) circuit is used during cranking.

FIELD BOOST

During the engines crank cycle, the control panel provides battery voltage (12 VDC) on Wire 56 to energize the starter contactor relay (SCR). Wire 56 also connects to Wire 4 (positive field voltage) through a field boost diode.

The field boost system is shown schematically in Figure 42. When the controller cranks the engine, battery voltage is applied through Wire 56 and the boost diode to Wire 4. This provides the current necessary to energize the field winding. The diode PREVENTS excitation voltage from feeding into wire 56 while the unit is running during normal operation.

Note: Field boost voltage is available only while the crank relay is energized (i.e. during the engines crank cycle).

CONTROLLER

BRIDGE

RECTIFIER

J5-12

ROTOR

J5-13

TO LOAD

MLB

MLB = MAIN LINE CIRCUIT BREAKER

SENSING

ENGINE DIRECT DRIVE

STATOR POWER

WINDING

MAGNETIC

FIELD

ROTOR

MAGNETIC

FIELD

STATOR POWER

WINDING

FIELD BOOST FROM

STATOR

EXCITATION

WINDING

CRANK CIRCUIT

VOLTAGE

REGULATOR

Figure 43. Operating Diagram

Field Excitation

The AC voltage from the DPE winding provides power to the AVR. The AVR rectifies and regulates the AC voltage to DC voltage, and provides the DC voltage to the rotor through Wires 4 and 0. When the starter disengages (cranking stopped), the AVR continues to provide excitation voltage to the rotor.

The AVR senses the AC output voltage through Sensing Wires 11 and 44, which are connected to the main power leads (11 and 44) in the stator can. The AVR will continue to increase excitation voltage to the rotor until the desired AC output voltage is reached. It will continue to “regulate” excitation voltage as necessary to provide a constant AC output voltage to the load.

CRANK RELAY

+12 VDC

FIELD BOOST DIODE +12 VDC

TO STARTER

STARTER CONTACTOR

Figure 42. Field Boost Circuit

OPERATION

Engine Cranking

When the engine is cranking, field boost voltage causes the rotor to magnetize. The rotor magnetic field induces a voltage into the stator AC power windings, and the stator excitation (DPE) windings. During cranking, field boost magnetism is capable of creating approximately one-half the unit’s rated voltage.

Page 42

100 V AC

STATOR

ROTOR

MAGNETIC FIELD

Figure 44. Low Excitation voltage = Low Magnetic lines of

Flux = Low AC Output.

Page 45

AC GENERATORS

STATOR

MAGNETIC FIELD

PART 2

200 V AC

ROTOR

Figure 45. Increased Excitation Voltage = Increased Magnetic

Lines of Flux = Increased AC Output Voltage.

The regulated excitation from the regulator is delivered to the rotor windings through Wire 4 and the positive brush and slip ring. This results in current flowing through the field windings to the negative slip ring and brush, and then to ground.

The greater the current flow through the windings the more concentrated the lines of flux around the rotor become. The more concentrated the lines of flux around the rotor, which cut across the stationary stator windings, the greater the voltage induced into the stator. Refer to Figures 44 and 45

Initially, the AC power windings output voltage “sensed” by the AVR is low. The AVR reacts by increasing the excitation voltage (and hence current flow) to the rotor until AC output voltage increases to a preset level. The AVR then maintains the voltage at this level. For example, if voltage exceeds the desired level, the AVR will decrease excitation. Conversely, if voltage drops below the desired level, the AVR responds by increasing excitation.

Section 2.2

Operational Analysis

AC Power Winding Output

When electrical loads are connected across the AC power windings to complete the circuit, current flows through the circuit powering the loads.

As load changes this will result in a corresponding change in voltage; as load demand increases the voltage will tend to drop; as load demand decreases the voltage will tend to increase. The AVR changes excitation to provide a constant output voltage with minimal increase or decrease during load changes. Frequency is also affected during load changes. However, frequency is a function of rotor speed (engine RPM); the engine electronic governor (integral to the control panel) will respond to any engine speed changes to maintain a stable, isochronous, frequency output of 60Hz.

The Automatic Voltage Regulator and the Electronic Governor work together to provide output voltage regulation of +/- 1% voltage regulation and +/- 0.25% steady state, isochronous, frequency (speed) regulation.

Page 43

Page 46

Section 2.3

Problem 1 – Generator Shuts Down for Under Voltage

Troubleshooting Flow Charts

PART 2

AC GENERATORS

INTRODUCTION

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 2.4. The first step in using the flow charts is to identify the correct problem on the following pages. For best results, perform all tests in the exact sequence shown in the flow charts.

RE-TEST

TEST 4 – PERFORM FIXED EXCITATION /

REPLACE

CONTROLLER

ROTOR AMP DRAW

REPAIR

OR REPLACE

FUSES

CHECK

VOM

FUSES

BAD

REPAIR

REPLACE

BAD

REPLACE

STATOR

ONLY

TEST 5 – TEST

SENSING CIRCUIT

WIRES 11 AND 44

GOOD

PERFORM STATOR

INSULATION

RESIST ANCE TEST

SECTION 1.5

GOOD

TEST 7 – TEST

STATOR

BAD

TEST 10 –

TEST ROTOR

ASSEMBLY

TEST 6 – TEST

EXCITATION

WINDING CIRCUIT

2 AND 6

GOOD

BAD

REPAIR

REPLACE

TEST 8 –

RESISTANCE

CHECK OF

ROTOR CIRCUIT

FIELD BOOST

CIRCUIT FAILURE

REPLACE HARNESS

BAD

GOOD

TEST 7 – TEST

STATOR

BAD

GOOD

ROTOR CIRCUIT

FAILURE

TEST 9 –

CHECK

BRUSHES &

SLIP RINGS

GOOD

TEST 10 –

TEST ROTOR

ASSEMBLY

GOOD

Page 44

BAD

REPLACE

ROTOR AND

STATOR

REPLACE

ROTOR ONLY

BAD

REPLACE

ROTOR AND

STATOR

PERFORM ROTOR

INSULATION

RESIST ANCE TEST

SECTION 1.5

Page 47

AC GENERATORS

Problem 1 – Generator Shuts Down for Under Voltage (Continued)

PART 2

Section 2.3

Troubleshooting Flow Charts

TEST 10 –

TEST ROTOR

ASSEMBLY

GOOD

PERFORM ROTOR

INSULATION

RESIST ANCE TEST

SECTION 1.5

GOOD

RE-TEST

TEST 4

BAD

TEST STATOR

GOOD

REPLACE

ROTOR

ONLY

TEST 4 – PERFORM FIXED EXCITATION /

ROTOR AMP DRAW

–

TEST 7

BAD

REPLACE

ROTOR

AND

STATOR

TEST 7 –

TEST STATOR

GOOD

PERFORM STATOR

INSULATION

RESIST ANCE TEST

SECTION 1.5

BAD

REPLACE

ROTOR

AND

STATOR

Problem 2 – Generator Produces High Voltage

BAD

TEST 10 –

TEST ROTOR

ASSEMBLY

GOOD

REPLACE

STATOR

ONLY

TEST 2 - CHECK

AC OUTPUT

VOLTAGE

REFER TO

PROBLEM 1

TEST 3 -

CALIBRATE

VOLTAGE

HIGH HIGH

VOLTAGE OUTPUT AT

BREAKER IS BELOW

220 OR ABOVE 270

TEST 11 - CHECK

AC OUTPUT

FREQUENCY

VOLTS AC

FREQUENCY O.K.,

BUT VOLTA GE

INCORRECT

VOLTAGE OUTPUT

AT BREAKER IS

BETWEEN

220-270 VA C

TEST 12 - CHECK

STEPPER MOTOR

CONTROL

FREQUENCY AND

VOLTAGE O.K.

STOP

TESTS

Page 45

Page 48

Section 2.3

Troubleshooting Flow Charts

PART 2

Problem 3 – Voltage and Frequency Drop Excessively When Loads Are Applied

AC GENERATORS

TEST 14 - CHECK

VOLTAGE AND

FREQUENCY

UNDER LOAD

GOOD

DISCONTINUE

TESTING

BOTH

LOW

TEST 15 - CHECK

FOR OVERLOAD

CONDITION

OVERLOADED

REDUCE LOADS TO UNIT’S

RATED CAPACITY

NOT

OVERLOADED

TEST 12 - CHECK

STEPPER MOTOR

CONTROL

REPAIR OR REPLACE

IF RECONFIGURED TO LP GAS, VERIFY THA T PROPER PROCEDURE WAS FOLLOWED (REFER TO SECTION 1.3)

GOOD

BAD

TEST 16 - CHECK

ENGINE CONDITION

GOOD

GO TO “PROBLEM 18 -

LOOK FOR A SHORTED CONDITION IN A CONNECTED LOAD OR IN ONE

OF THE LOAD CIRCUITS

REPAIR OR REPLACE

GOOD

TEST 7 - CHECK

STATOR AC

POWER WINDINGS

BAD

ENGINE

CONDITION

GOOD

ENGINE STARTS HARD

AND RUNS

ROUGH/LACKS POWER”

SECTION 4.3

Problem 4 – Unstable Voltage or Incorrect Output Which is Not Triggering a Shutdown

TEST 1 – CHECK

AC OUTPUT

VOLTAGE

HIGH

LOW

TEST 3 -

CALIBRATE

VOLTAGE

ERRATIC

PROCEED TO PROBLEM 1

Page 46

Page 49

AC GENERATORS

PART 2

Section 2.4

Diagnostic Tests

INTRODUCTION

This section familiarizes the service technician with acceptable procedure for the testing and evaluation of various problems that can occur on the standby generators with air-cooled engines. Use this section in conjunction with Section 2.3, “Troubleshooting Flow Charts.” The numbered tests in this section correspond with those of Section 2.3.

Some test procedures in this section may require the use of specialized test equipment, meters or tools. Most tests can be performed with an inexpensive Volt-Ohm-Milliammeter (VOM). An AC frequency meter is required where frequency readings must be taken. To measure AC loads it is acceptable to use a clamp-on ammeter.

Testing and troubleshooting methods covered in this section are not exhaustive. No attempt has been made to discuss, evaluate and advise the home standby service trade of all conceivable ways in which service and trouble diagnosis must be performed. 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 products safety.

SAFETY

Service personnel who work on this equipment should be 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 ignite 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 do not understand a component, device or system, do not work on it.

TEST 1 – CHECK AC OUTPUT VOLTAGE

Discussion

Use a Volt-Ohm-Milliammeter (VOM) to check the Generators output voltage. Test output voltages at the unit’s main circuit breaker (MLCB) terminals. Refer to the unit’s Data Plate for rated line-to-line and line-to-neutral voltages.

Use extreme caution 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 the meter clamps are securely attached and will not shake loose.

Procedure

1. Set the Volt-Ohm-Milliammeter (VOM) to measure AC voltage.

2. With the engine shut down, connect the meter test leads across the load terminals of the Generators MLCB. This will measure line-to-line voltage. See Figure 46.

LINE

TEST POINT

LOAD

AC TR OUBLESHOOTING

It is always good practice to continue to ask questions during the troubleshooting process. When evaluating the problem asking some of these questions may help identify the problem quicker.

•What is the generator supposed to do?

•What fault (Alarm) is shutting the generator down?

•Is the fault a symptom of another problem?

•Does the generator have the same fault consistently?

•When does the fault occur?

•After the fault occurred what was displayed in the LCD?

•Why would this happen?

•How would this happen?

•What type of test will either prove or disprove the cause of

the fault?

TEST POINT

Figure 46. Test 2 Test Points

3. Set the MLCB to the “Open” position. Ensure that all electrical loads are disconnected from the Generator.

4. Set the AUTO-OFF-MANUAL switch to the MANUAL position.

Note: AC under and over-voltage shut downs have a 10 second delay.

5. Set the MLCB to the “Closed” position. Measure and record the voltage.

6. Set the AUTO-OFF-MANUAL switch to the OFF position.

Results

1. If the VOM indicated approximately 240-244 VAC, the output voltage is good.

Page 47

Page 50

Section 2.4

Diagnostic Tests

PART 2

AC GENERATORS

2. If the VOM indicated any other readings the voltage is BAD. Refer back to the flow chart.

Note: “Residual” voltage may be defined as the voltage 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 VAC, 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 engines, “field boost” current flow is available to the rotor only during engine cranking.

TEST 3 – CALIBRATE VOLTAGE

Discussion

When voltage output is too high, it is possible to adjust voltage output of the generator. To access this menu a password will be required to be entered into controller. Replacement controllers do not require calibration unless output is not within the specifications. (Refer to the Specifications section in the front of this manual.)

Procedure

1. Set Volt-Ohm-Meter (VOM) to measure AC voltage.

2. Set up the VOM to measure output voltage on the breaker.

3. Open the Main Line Circuit Breaker (MLCB) on the generator.

4. On the controller, press the ESC key until the main menu is present. (Refer to the Menu Navigation found in Section 1.10)

5. While at this screen proceed to enter the following password:

UP, UP, ESC, DOWN, UP, ESC, UP, UP

6. After the password has been entered, proceed to the EDIT menu.

7. Press the down arrow key until the screen indicates CALIBRATE VOLTAGE and press ENTER.

8. After pressing enter, a value will appear on the screen.

Note: The default setting from the factory for calibration is 1024.

9. Set AUTO-OFF-MANUAL switch to the MANUAL position.

10. While the unit is running, use the UP or DOWN arrows to adjust the calibration setting. A higher value will create a lower voltage at the breaker and vice versa a lower value will create a higher voltage at the breaker.

Note: The Calibration Setting will reset to being a password protected option after the controller is left idle.

Verification

While the unit is running, verify that the output voltage at the breaker is consistent within 5 volts to what the controller displays in the DEBUG menu under OUTPUTS. (Refer to Section

1.10 Menu Navigation).

Results

1. If during the verification process the output voltage at the breaker and the display match and the calibration setting was not adjusted outside of the window, stop testing.

2. If a correct voltage output was not achieved using the window specified, refer to “Problem 1 – Test 4 Fixed Excitation / Rotor Amp draw test.”

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. With the use of the MIN/MAX feature of a Volt-Ohm-Meter (VOM), it is possible to capture the maximum output of a particular winding before faulting out on under-voltage.

Under-voltage Alarm – When the AUTO-OFF-MANUAL is set in the MANUAL position the following logic is used to trigger the alarm “under-voltage”:

•Cranking – If the starter disengages before a voltage has

developed in the stator the controller will initiate a shutdown alarm for “under-voltage.”

Note: For further information about under-voltage shutdowns, refer to Section 2.1 “Description and Components.”

Table 9 has been provided to record the results of the following procedure. These results may be required when requesting factory support. Additional copies of Table 9 can be found in Appendix A “Supplemental Worksheets” at the back of this manual.

Table 9. Test 4 Results Worksheet

Test Point Results

Wires 2 and 6 Voltage

Wires 11 and 44 Voltage

Static Rotor Amp Draw

VAC

Amps

Calibration factor must NOT be adjusted below 990 or



above 1040. Adjusting outside of this window could result in damage to the machine.

11. Once a desired output voltage has been achieved, press ENTER to save the new setting.

Page 48

Running Rotor Amp Draw

Column Identified

Amps

Page 51

AC GENERATORS

PART 2

Section 2.4

Diagnostic Tests

Required Tools

•A Volt-Ohm-Meter (VOM) equipped with a MIN/MAX feature

•Meter test leads that are capable of measuring voltage inside

a connector without damaging the socket. A set of black and red test leads for this application are available from the manufacturer. Contact your nearest servicing dealer for more information.

Note: It is not recommended to use any testing device other than the manufactures approved test lead adapters (P/N 0J09460SRV).

Figure 47. Narrow Test Probe

VOM Setup

Below is an excerpt taken from a Fluke 117 multi-meter owners manual.

MIN/MAX – The MIN MAX AVG recording mode captures the minimum and maximum input values (ignoring overloads), and calculates a running average of all readings. When a new high or low is detected, the Meter beeps.

•Put the Meter in the desired measurement function and range.

•Press to enter MIN MAX AVG mode.

• MIN MAX and MAX are displayed and the highest reading

detected since entering MIN MAX AVG is displayed.

•Press and present readings.

•To pause MIN MAX AVG recording without erasing stored values, press

•To resume MIN MAX AVG recording, press

•To exit and erase stored readings, press for at least

one second or turn the rotary switch.

RANGE – When you turn the Meter on, it defaults to Autorange and Auto is displayed.

1. To enter the Manual Range mode, press . Manual is

displayed.

2. In the Manual Range mode, press to increment the

range. After the highest range, the Meter wraps to the lowest range.

Note: You cannot manually change the range in the MIN MAX AVG or Display HOLD modes.

If you press the Meter beeps twice, indicating an invalid operation, and the range does not change.

3. To exit Manual Range, press for at least 1 second or

turn the rotary switch. The Meter returns to Autorange and Auto is displayed.

to step through the low (MIN), average (AVG),

. HOLD is displayed.

again.

while in MIN MAX AVG or Display Hold,

2. Locate and disconnect the J5 connector from the controller.

3. Set VOM to measure AC voltage.

4. Using the scale feature of the VOM, set to the first available scale greater than 100 (i.e. “600”).

Note: Refer to the manufactures owners manual for specific information on using manual scaling

MIN/MAX MAX

0.00 VAC

Figure 48.

5. Set meter to MIN/MAX.

Note: Refer to the manufactures owners manual for specific information on using the MIN/MAX feature.

6. Using the approved meter test probes, connect one meter test lead to Pin 14-J5 (Wire 6) and the other meter test lead to Pin 5-J5 (Wire 2).

7. Re-install the 7.5 amp fuse.

8. Set the AUTO-OFF-MANUAL switch to the MANUAL position.

9. Measure and record the voltage indicated between Wires 2 and 6 as indicated by the VOM.

10. Acknowledge and reset the “under-voltage” present on the controller; leave AUTO-OFF-MANUAL switch in the OFF position.

11. Re-locate meter test probes to Pin 11-J5 (Wire 11) and Pin 10-J5 (Wire 44).

12. Set the AUTO-OFF-MANUAL switch to the MANUAL position.

13. Measure and record the voltage indicated between Wire 11 and 44 as indicated by the VOM.

14. Acknowledge and reset the “under-voltage” present on the controller; leave AUTO-OFF-MANUAL switch in the OFF position.

600

Procedure: Fixed Excitation Test

1. Remove the 7.5 amp fuse from the controller.

Page 49

Page 52

Section 2.4

Diagnostic Tests

63 V AC

PIN 5

4 3 2 1

9 8 7 6

PIN 14

J5 CONNECTOR HARNESS SIDE

Figure 49. 10-20kW Fixed Excitation Test

Procedure: Rotor Amp Draw

1. Disengage the MIN/MAX feature and manual scale on the VOM.

2. Set VOM to measure DC amperage.

Note: Consult the meters documentation for proper setup procedure. See Section 1.4 “Measuring Current” for further information.

3. Connect the black (negative) meter test lead to Pin 13-J5 and the red (positive) test lead to the positive battery terminal. See Figure 50.

4. Measure and record the static rotor amp draw.

5. Set AUTO-OFF-MANUAL switch to the MANUAL position.

6. Measure and record the running rotor amp draw.

7. Acknowledge and reset the “under-voltage” present on the

1014 13 12 11

PART 2

AC GENERATORS

controller; leave AUTO-OFF-MANUAL switch in the OFF position.

Results

1. Using the values recorded in the above procedure, compare the results to Table 10 “Results – Fixed Excitation Test/Rotor Amp Draw Test”. Determine the appropriate lettered column to use and refer back to the flow chart. The rotor amp draws area calculated amp draw and actual amperage readings may vary depending on the resistance of the rotor.

Note: To calculate rotor amp draw take the battery voltage applied, divided by the actual resistance reading of the rotor. Rotor resistance can be measured between Pin 13 J5 and Pin 12 J5.

12.9VDC

12.3 Ohms x 1.05 DC Amps

Example

Model 17kW

Wires 2 and 6 Voltage 53 VAC

Wires 11 and 22 Voltage 31 VAC

Static Rotor Amp Draw 1.09 Amp

Running Rotor Amp Draw 1.10 Amp

These results match Column B in the chart. Refer back to Problem 1 and follow letter “B”

Figure 50.

J5 CONNECTOR

HARNESS SIDE

4 3 2 1

9 8 7 6

ROTOR

FIELD BOOST DIODE

Page 50

11.83Ω

1.09 DC Amps

BATTERY

+ -

1014 13 12 11

PIN 13

RED

12.9 VDC

J5 PIN 12

J5 PIN 13

1.09 DC Amps

VOM METER

1.09 A

POSITIVE BATTERY

TERMINAL

12.9 VDC

11.83Ω

OHM’S LAW

Figure 51. Rotor Amp Draw Test

Page 53

AC GENERATORS

PART 2

Section 2.4

Diagnostic Tests

Table 10. TEST 4 Results – Fixed Excitation Test/Rotor Amp Draw Test (8-20kW)

Results: Size A B C D E F G H

Voltage Results Wire 2 & 6

Voltage Results Wire 11 & 44

8kW

10kW

12kW

Static Rotor Amp Draw

Running Rotor Amp Draw

Note: Actual values measured may vary by as much as .5 amps; depending on the type and quality of meter used, the condition of the unit, and how good the connection is between the test leads and test points.

14kW

15kW

16kW

17kW

20kW

8kW

10kW

12kW

14kW

15kW

16kW

17kW

20kW

MATCH RESULTS WITH LETTER AND REFER TO FLOW CHART IN SECTION 2.3 “Problem 1”

ALL

Above 50

VAC

Above 50

VAC

1.76-2.05

1.46-1.70

1.33-1.54

1.16-1.36

1.76-2.05

1.46-1.70

1.33-1.54

1.16-1.36

Above 50

VAC

Below 50

VAC

1.76-2.05

1.46-1.70

1.33-1.54

1.16-1.36

1.76-2.05

1.46-1.70

1.33-1.54

1.16-1.36

Below 50

VAC

Above 50

VAC

1.76-2.05

1.46-1.70

1.33-1.54

1.16-1.36

1.76-2.05

1.46-1.70

1.33-1.54

1.16-1.36

Zero or

Residual

Volts

Zero or

Residual

Volts

Zero Current

Draw

Zero Current

Draw

Below 50

VAC

Below 50

VAC

Above 2.5A

Above 2.3A

Above 2.0A

Above 2.5A

Above 2.3A

Above 2.0A

Below 50

VAC

Below 50

VAC

1.76-2.05

1.46-1.70

1.33-1.54

1.16-1.36

1.76-2.05

1.46-1.70

1.33-1.54

1.16-1.36

Above 50

VAC

Above 50

VAC

Zero Current

Draw

Zero Current

Draw

Below 50

VAC

Below 50

VAC

1.76-2.05

1.46-1.70

1.46-1.71

1.33-1.54

1.16-1.36

Above 2.5A

TEST 5 – TEST SENSING CIRCUIT

WIRES 11 AND 44

Discussion

The voltage regulator (internal to the controller) requires a reference voltage in order to regulate at a specific voltage and to recognize if the alternator is producing voltage. The alternator may be producing a voltage, but if the voltage regulator cannot “sense” the voltage, it will fault out for under-voltage. This test will verify the integrity of the sensing circuit.

Required Tools

•Meter test leads that are capable of measuring voltage inside a connector without damaging the socket. A set of black and red test leads for this application are available from the manufacturer. Contact your nearest servicing dealer for more information. See Figure 47.

Note: It is not recommended to use any testing device other than the manufactures approved test lead adapters.

Procedure

1. Remove the 7.5 amp fuse from the control panel.

2. Remove the controller and the cover to expose the lower

harness connections.

3. Disconnect the J5 connector from the controller.

4. Set the Volt-Ohm-Milliammeter (VOM) to measure resistance.

Note Stator winding resistance values are very low and some VOM’s will not read such a low resistance, and will simply indicate different ranges of resistance. The manufacture recommends a high quality digital type meter capable of reading a very low resistance.

5. Connect one-meter test lead to J5 Pin 11 (Wire 11) and the other meter test lead to the NEUTRAL connection. Measure and record the resistance.

6. Connect one-meter test lead to J5 Pin 10 (Wire 44) and the other meter test lead to the NEUTRAL connection. Measure and record the resistance.

a. If the meter indicated a resistance value of less than

0.2 ohms in Steps 5 and 6, stop testing and refer back to the flow chart (Good).

b. If the meter indicated OPEN in Steps 5 or 6, proceed to

Step 7.

7. Disconnect the lower bulkhead C1 connector (Figure 52).

8. Connect one-meter test lead to C1 Pin 2 (Wire 11) and the other meter test lead to the NEUTRAL connection, measure and record the resistance.

Page 51

Page 54

Section 2.4

Diagnostic Tests

PART 2

AC GENERATORS

9. Connect one-meter test lead to C1 Pin 1 (Wire 44) and the other meter test lead to the NEUTRAL connection, measure and record the resistance.

Results

1. If the meter indicated a resistance value of less than

0.2 ohms in Steps 5 through 9, refer back to flow chart (Good).

CI CONNECTOR

Figure 52. C1 Connector

2. If the meter indicated a resistance value of OPEN in Step 5 and a value less than 0.2 ohms in Step 8, repair or replace Wire 11 between the controller and the C1 connector.

3. If the meter indicated a resistance value of OPEN in Step 6 and a value less than 0.2 ohms in Step 9, repair or replace Wire 44 between the controller and the C1 connector.

4. If the meter indicated OPEN in either Step 8 or Step 9, proceed to Test 7 “Test Stator.”

Procedure

1. Remove the 7.5 amp fuse from the control panel.

2. Remove the controller and the cover to expose the lower harness connections.

3. Disconnect the J5 connector from the controller.

4. Set the Volt-Ohm-Milliammeter (VOM) to measure resistance.

5. Connect one-meter test lead to J5 Pin 5 (Wire 2) and the other meter test lead to J5 Pin 14 (Wire 6). Measure and record the resistance.

a. If the meter indicated a resistance value of less than

0.2 ohms in Step 5, stop testing and refer back to the flow chart (Good).

b. If the meter indicated OPEN in Step 5, proceed to Step 6.

6. Disconnect the lower bulkhead C1 connector.

7. Connect one-meter test lead to C1 Pin 4 (Wire 2) and the other meter test lead to C1 Pin 3 (Wire 6). Measure and record the resistance.

Results

1. If the meter indicated a resistance value of less than 0.2 ohms in Steps 5 through 9, refer back to the flow chart (Good).

2. If the meter indicated a resistance value of OPEN in Step 5 and a value less than 0.2 ohms in Step 7, repair or replace Wire 2 and 6 between the controller and the C1 connector.

3. If the meter indicated a resistance value of OPEN in Step 7, verify connection, then replace the stator.

TEST 6 – TEST EXCITATION WINDING

CIRCUIT 2 AND 6

Discussion

The voltage regulator (internal to the controller) requires an unregulated voltage in order to regulate DC excitation current to the rotor. The alternator may be producing a voltage, but if the voltage regulator cannot “sense” the voltage, it will fault out for under-voltage. This test will verify the integrity of the Excitation winding inside the stator.

Required Tools

Note: It is not recommended to use any testing device other than the manufactures approved test lead adapters.

Page 52

TEST 7 – TEST THE STATOR WITH A VOM

Discussion

This test will use a Volt-Ohm-Milliammeter (VOM) to test the stator windings for the following faults:

•An OPEN circuit condition

•A “shor t-to-ground” condition

•A shor t circuit between windings

Table 14 (next page) has been provided to record the results of the following procedure. These results may be required when requesting factory support.

Additional copies of Table 14 can be found in Appendix A “Supplemental Worksheets” at the back of this manual.

Note: It is the recommendation of the factory to preform this test procedure using piercing probes on the wire side of the connector. Testing inside the connector itself can cause unneeded damage to the unit resulting in poor or loose connections.

Page 55

AC GENERATORS

PART 2

Section 2.4

Diagnostic Tests

Procedure: Resistance Test

1. Disconnect Wires 11 and 44 from the main line circuit breaker (MLCB).

2. Disconnect Wires 22 and 33 from the NEUTRAL connection and separate the leads.

3. Disconnect the bulkhead C1 connector.

4. Make sure all of the disconnected leads are isolated from each other and are not touching the frame during the test.

5. Set the VOM to measure resistance.

6. Measure and record the resistance values for each set of windings between the A and B test points as shown in Table 11. Record the results in Table 14.

3 2 1

6 5 4

Figure 53. C1 Bulkhead Connector Pin Locations

CONFIGURATION A

PIN #

CLOSEST TO

BEARING

STATOR

2 6

TO C1 SEE TABLE FOR PINOUT

33 44

44 11

6 2

4 0

Figure 54. Stator Lead Connections

Table 11. Test Points

Test Point A Test Point B

Stator Lead Wire 11 Stator Lead 22

Stator Lead Wire 33 Stator Lead 44

C1 Pin 2 Wire 11 Stator Lead 22

C1 Pin 1 Wire 44 Stator Lead 33

C1 Pin 3 Wire 6 C1 Pin 4 Wire 2

44 11

6 2

4 0

CONFIGURATION B

44 11

6 2

4 0

PIN #

5 6

4 0

Test Windings for a Short to Ground

7. Make sure all stator leads are isolated from each other and are not touching the frame.

8. Measure and record the resistance values for each set of windings between the A and B test points as shown in Table 12. Record the results in Table 14.

Table 12. Test Points

Test Point A Test Point B

Stator Lead 11 Ground

Stator Lead 44 Ground

C1 Pin 1 Wire 44 Ground

C1 Pin 2 Wire 11 Ground

C1 Pin 4 Wire 2 Ground

Test For A Short Circuit Between Windings

9. Measure and record the resistance values for each set of windings between the A and B test points as shown in Table 13. Record the results in Table 14.

Table 13. Test Points

Test Point A Test Point B

C1 Pin 4 Wire 2 C1 Pin 2 Wire 11

C1 Pin 4 Wire 2 C1 Pin 2 Wire 44

C1 Pin 4 Wire 2 Stator Lead Wire 11

C1 Pin 4 Wire 2 Stator Lead Wire 44

Stator Lead 11 C1 Pin 1 Wire 44

Stator Lead 11 Stator lead Wire 44

Table 14. Test 7 Stator Results

Test Point A Test Point B Results

Resistance Tests Stator Lead Wire 11 Stator Lead 22 Stator Lead Wire 33 Stator Lead 44 C1 Pin 2 Wire 11 Stator Lead 22 C1 Pin 1 Wire 44 Stator Lead 33 C1 Pin 3 Wire 6 C1 Pin 4 Wire 2

Shorts to Ground Stator Lead 11 Ground Stator Lead 44 Ground C1 Pin 1 Wire 44 Ground C1 Pin 2 Wire 11 Ground C1 Pin 4 Wire 2 Ground

Shorted Condition C1 Pin 4 Wire 2 C1 Pin 2 Wire 11 C1 Pin 4 Wire 2 C1 Pin 2 Wire 44 C1 Pin 4 Wire 2 Stator Lead Wire 11 C1 Pin 4 Wire 2 Stator Lead Wire 44 Stator Lead 11 C1 Pin 1 Wire 44 Stator Lead 11 Stator lead Wire 44

Note: These results may be needed when requesting factory support.

Page 53

Page 56

Section 2.4

Diagnostic Tests

PART 2

AC GENERATORS

Note: Stator winding resistance values are very low and some VOM’s will not read such a low resistance, and will simply indicate CONTINUITY. The manufacture recommends a high quality digital type meter capable of reading a very low resistance.

Results

1. Resistance Test: If the VOM indicated a very high resistance or INFINITY, the windings are open or partially open.

2. Grounded Condition: Any resistance value other than INFINITY indicates a grounded winding.

3. Shorted Condition: Any resistance value other than INFINITY indicates a shorted winding.

Note: Read Section 1.5, “Testing, Cleaning and Drying” carefully. If the winding tests good, perform the insulation resistance test. If the winding fails the insulation resistance test (using a meg-ohm-meter), 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.

TEST 8 – RESISTANCE CHECK OF ROTOR

CIRCUIT

Discussion

During the rotor amp draw test in Test 4, if the amp draw was zero, then an OPEN circuit should be present on Wires 4 and

0. This test will verify if the readings were accurate and verify

the field boost circuit.

Identify C1 Connector wiring configuration. Refer to Figure 54.

Configuration A: follow Steps 1-11

Configuration B: follow Steps 1-6

7. If testing C1 Configuration A, locate and disconnect the bulkhead C1 connector. If testing C1 Configuration B, stop test and refer to Test 8 Results.

8. Connect one-meter test lead to C1 Pin 5 (Wire 4) and connect the other meter test lead to C1 Pin 6 (Wire 0), measure and record the resistance. If the VOM indicated INFINITY, stop testing and refer back to flow chart (Rotor Circuit Failure).

9. Locate the starter contactor relay (SCR) and disconnect Wire 56 (blue wire).

10. Disconnect the J4 connector from the controller.

11. Connect one meter test lead to the disconnected Wire 56 and connect the other meter test lead to J5 Pin 13 (Wire 4). Measure and record the resistance.

Results

Refer to the front of this manual for correct Rotor resistance values.

1. If the VOM indicated the correct resistance values in Steps 5, 6, 8, and 11, refer back to flowchart (Good).

2. If the VOM indicated INFINITY in Step 8, refer back to flowchart (Rotor Circuit Failure).

3. If the VOM indicated the correct resistance in Step 8 and indicated INFINITY in Step 5, repair or replace Wires 4 and 0 between the C1 and the J5 connector.

4. If the VOM indicated the correct resistance in Step 8 and indicated INFINITY in Step 5, but indicated the correct resistance in Step 6, repair or replace Wire 0 between the J5 connector and the ground connection.

Procedure

1. Remove the 7.5 amp fuse from the control panel.

2. Remove the cover and controller to expose the lower harness connections.

3. Disconnect the J5 connector from the controller

4. Set the Volt-Ohm-Milliammeter (VOM) to measure resistance.

5. Connect one-meter test to lead to J5 Pin 13 (Wire 4) and connect the other meter test lead to J5 Pin 12 (Wire 0), measure and record the resistance.

6. Connect one-meter test to lead to J5 Pin 13 (Wire 4) and connect the other meter test lead to a clean frame ground, measure and record the resistance.

a. If the meter indicated the correct Rotor resistance

values as stated in the front of the manual, proceed to Step 9.

b. If the meter indicated INFINITY, proceed to Step 7.

Page 54

5. If the VOM indicated the correct resistance in Step 5 and indicated INFINITY in Step 11, replace the harness (Field Boost Circuit Failure).

TEST 9 – CHECK BRUSHES AND SLIP RINGS

Discussion

The brushes and slip rings function to provide an electrical connection for excitation current from the stationary components to the rotating rotor. Made of a special long lasting material, brushes 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 current. Such a non-conducting film usually develops during non-operating periods. Broken or disconnected wiring can also cause loss of excitation current to the rotor.

Refer to Figure 54 to identify the C1 Connector wiring configuration of the unit being tested. Follow steps for Configuration A or Configuration B accordingly.

Page 57

AC GENERATORS

PART 2

Section 2.4

Diagnostic Tests

Procedure

1. Disassemble the Generator until the brushes and slip rings are exposed. Refer to Section 6.1 “Major Disassembly.”

2. Inspect the brush wires and verify they are secured and properly connected.

3. Inspect the brush assembly for excessive wear, or damage.

4. Inspect the rotor slip rings. If their appearance is dull or tarnished, polish with a fine grade abrasive material.

Do not use metallic grit to polish slip rings. This may



cause irreversible damage to the rotor.

5. Wire 0, located on the negative brush terminal, provides an electrical connection to ground for the rotor and the voltage regulator. To test this wire for an OPEN condition, remove Wire 0 from the brush assembly.

6. For C1 Configuration A disconnect the bulkhead connector C1 inside the control panel. For C1 Configuration B disconnect the J5 connector from the controller and isolate Wire 0 from the ground stud.

7. Set Volt-Ohm-Milliammeter (VOM) to measure resistance.

For C1 Configuration A c Wire 0 at the brush assembly and connect the other meter test lead to C1 Pin 6. one meter test lead to Wire 0 at the brush assembly and connect the other meter test lead to the Wire 0 disconnected in Step 6.

•If the VOM indicated INFINITY, repair or replace Wire 0

between the negative slip ring and C1 Pin 6 (Configuration A) or the ground stud (Configuration B).

•If the VOM indicated CONTINUITY, continue to Step 9.

9. Wire 4, located on the positive brush terminal, provides an electrical connection for excitation current to flow between the rotor and the voltage regulator. To test this wire for an OPEN condition, remove Wire 0 from the brush assembly.

10. For C1 Configuration A connect one meter test lead to Wire 4 at the brush assembly and connect the other meter test lead C1 Pin 5. For C1 Configuration B connect one meter test lead to Wire 4 a the brush assembly and connect the other meter test lead to J5 Pin 13.

•If the VOM indicated INFINITY, repair or replace Wire 4

between the positive slip ring and C1 Pin 6 (Configuration A) or J5 Pin 13 ( Configuration B).

•If the VOM indicated CONTINUITY, continue to Step 11.

11. Connect one meter test lead to Wire 4 at the brush assembly and connect the other meter test lead to frame ground.

onnect one meter test lead to

For C1 Configuration B c

onnect

•If the VOM indicated CONTINUITY, repair or replace Wire 4 between the positive slip ring and C1 Pin 6 (Configuration A) or J5 Pin 13 ( Configuration B).

•If the VOM indicated INFINITY, continue to Step 12.

12. Connect one meter test lead to Wire 0 at the brush

assembly and connect the other meter test lead to a clean frame ground.

•If the VOM indicated INFINITY , repair or replace Wire 0 between the positive slip ring and the control panel ground connection.

•If the VOM indicated CONTINUITY, refer back to flow chart.

Results

1. Repair, replace, or reconnect wires as necessary.

2. Replace any damage slip rings or brush holder.

3. Clean and polish slip rings as required.

TEST 10 – TEST ROTOR ASSEMBLY

Discussion

A rotor having 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

1. Remove the brush assembly from the slip rings to prevent

interaction.

2. Set a Volt-Ohm-Milliammeter (VOM) to measure

resistance.

3. Connect one meter test lead to the positive slip ring

(nearest the rotor bearing) and the common test lead to the negative slip ring, measure and record the resistance.

4. Connect one meter test lead to the positive slip ring and

connect the other meter test lead to a clean frame ground, measure and record the resistance.

Results

1. Compare the resistance measured in Step 3 with the

“Specifications”, replace rotor as required.

2. If the VOM indicated CONTINUITY in Step 4, replace the

rotor assembly.

TEST 11 – 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.

Page 55

Page 58

Section 2.4

STEPPER MOTOR

STEPPER MOTOR ARM

PULL ARM THIS DIRECTION TO CLOSE THROTTLE

Diagnostic Tests

PART 2

AC GENERATORS

Tools Required

•A meter that is capable of measuring AC frequency

Procedure

1. See Figure 46, connect an accurate AC frequency meter across the Wires 11 and 44 Terminals of the generator main line circuit breaker (MLCB)

2. Set the AUTO-OFF-MANUAL to the MANUAL position.

3. Let engine stabilize. Measure and record the frequency.

Results

1. If the meter indicated 59-61 Her tz, refer back to flow chart

2. If the meter indicated a value outside the accepted range, refer back to flow chart.

TEST 12 – CHECK STEPPER MOTOR

CONTROL

Procedure: V-Twin

1. Remove air cleaner cover to access Stepper motor.

STEPPER MOTOR

PULL ARM THIS DIRECTION TO CLOSE THROTTLE

STEPPER MOTOR ARM

Figure 56. Throttle Positions 9/10kW Units

2. Physically move 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. The Stepper motor will have resistance as it moves through its travel.

3. Physically move the throttle to the closed position by pulling the Stepper motor arm towards the idle stop. See Figure 55 for 8kW units, Figure 56 for 10kW units, and Figure 57 for 12-20kW units.

4. Set the AUTO-OFF-MANUAL switch to the MANUAL position.

5. Observe record the Stepper motors movement.

6. Set the AUTO-OFF-MANUAL switch to the OFF position.

STEPPER MOTOR

Figure 57. Throttle Positions 12-20kW Units

7. Physically move the throttle to the open position by pulling the Stepper motor arm away from the idle stop.

8. Set the AUTO-OFF-MANUAL switch to the MANUAL position.

9. Observe and record the Stepper motors movement.

10. Set the AUTO-OFF-MANUAL switch to the OFF position.

11. If no movement was seen in Step 5 or 6 remove the controller and verify the six pin connector on the controller is seated properly, remove the connector and then replace it and test again. If problems persist, proceed to Step 12.

PULL ARM THIS DIRECTION TO CLOSE THROTTLE

Figure 55. Throttle Positions 8kW Units

Page 56

12. Set Volt-Ohm-Milliammeter (VOM) to measure resistance.

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

13. Connect the meter test leads across points A and B as shown in Table 15 and compare to the specified value. See Figure 58 for pin locations.

Page 59

AC GENERATORS

RED

EMPTY

YELLOW

BROWN

ORANGE

BLACK

PART 2

Section 2.4

Diagnostic Tests

Table 15. Stepper Motor Testing

Test Point A Test Point B Resistance Value

Red Orange 10Ω

Red Yellow 10Ω

Red Brown 10Ω

Red Black 10Ω

Red Ground INFINITY

Figure 58. Six Pin Connector Wire Colors

Results

1. If the Stepper motor in Step 5 moved to the wide-open position, the closed position in Step 9, and the VOM indicated CORRECT resistance values, refer back to flow chart.

2. If the Stepper motor failed to change the throttle position in Steps 5 or 9, replace Stepper motor.

3. If the Stepper motor in Step 5 moved to the wide-open position, the closed position in Step 9, and the VOM indicated IN-CORRECT resistance values, replace Stepper motor.

TEST 14 – CHECK VOLTAGE AND

FREQUENCY UNDER LOAD

4. Apply electrical loads to the Generator equal to the rated capacity of the unit. Measure and record the frequency and the voltage.

Results

1. If the VOM indicated 60 Hz and approximately 248 VAC during full load, discontinue testing.

2. If the VOM indicated a frequency and voltage that dropped while under full load, refer back to flow chart.

TEST 15 – CHECK FOR AN 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 recommended method is to use an ammeter. See Section 1.4 “Measuring Current.”

Procedure

1. Connect the clamp-on ammeter to the Generator according to the ammeters manufacture specifications.

2. Transfer all normal electrical loads to the Generator, measure and record the amperage.

Results

1. If the ammeter indicated amperage readings that were ABOVE the unit’s specified ratings, reduce loads to the units rated capacity.

2. If the ammeter indicated amperage readings that were BELOW the unit’s specified ratings, but RPM and frequency dropped excessively refer back to flowchart.

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 performance, or (c) a shorted condition in the stator windings or in one or more connected loads.

Procedure

1. Set Volt-Ohm-Milliammeter (VOM) to measure AC voltage.

2. Connect an accurate AC frequency meter and an AC voltmeter across the stator AC power winding leads.

3. Start the engine, let it stabilize and warm-up.

TEST 16 – CHECK ENGINE CONDITION

Discussion

If engine speed and frequency drop excessively under load, the engine may be underpowered. An underpowered engine can be the result of a dirty air cleaner, loss of engine compression, faulty fuel settings, or incorrect ignition timing, etc. A decrease in available horsepower will proportionally lead to a decrease in kW.

Procedure

For engine testing, troubleshooting, and repair procedures refer to Section 4.3. For further engine repair information, refer to the appropriate engine service manuals.

Page 57

Page 60

NOTES

PART 2

AC GENERATORS

Page 58

Page 61

PART 3

TRANSFER SWITCH

Air-cooled, Automatic

Standby Generators

TABLE OF CONTENTS

SECTION TITLE PAGE

3.1 Description and Components 60

3.2 Operational Analysis 64

3.3 Troubleshooting Flow Charts 73

3.4 Diagnostic T ests 76

Section 3.1 – Description and Components