Generac power systems Corepower Operating instructions

DIAGNOSTIC

REPAIR

MANUAL

STANDBY GENERATORS

CorePower Home Standby Generator

MODELS:

6/7 kW

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.

READTHIS MANUALTHOROUGHLY

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.

Foreword

Page 1

SAFETY ..............................................................................2

Read This Manual Thoroughly.............................................2

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

Generator ............................................................... 4

Engine.................................................................... 4

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

Major Features........................................................ 5

PART 1 – GENERAL INFORMATION ......................................9

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

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

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

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

Section 1.2 – Measuring Electricity ...................................11

Meters.................................................................. 11

The VOM .............................................................. 11

Measuring AC Voltage........................................... 11

Measuring DC Voltage........................................... 11

Measuring AC Frequency ...................................... 11

Measuring Current ................................................ 12

Measuring Resistance........................................... 12

Electrical Units...................................................... 13

Ohm’s Law........................................................... 13

Section 1.3 – Preparation Before Use................................14

Introduction .......................................................... 14

Fuel Consumption................................................. 14

Reconfigure the fuel system.................................. 14

Section 1.4 – Operating Instructions .................................16

Control Panel........................................................ 16

User Interface....................................................... 16

Automatic Operation ............................................. 16

Manual Operation.................................................. 16

Section 1.5 – Automatic Operating Parameters..................18

Introduction .......................................................... 18

Utility Failure......................................................... 18

Cranking............................................................... 18

Cranking conditions .............................................. 18

Load Transfer Parameters ..................................... 18

Section 1.6 – General Maintenance...................................20

Introduction .......................................................... 20

Engine Oil ............................................................. 20

Engine Oil Recommendations................................ 20

Air Filter................................................................ 20

Spark Plugs.......................................................... 20

Visual Inspection .................................................. 20

Corrosion Protection............................................. 20

Valve Clearance .................................................... 20

Battery ................................................................. 21

Section 1.7 – General Troubleshooting ..............................22

Introduction .......................................................... 22

Recommended Tools ............................................ 22

Troubleshooting Reminders and Tips..................... 22

Connectors........................................................... 22

PART 2 – AC Generators ....................................................23

Section 2.1 – Description and Components.......................24

Introduction .......................................................... 24

Engine-Generator Drive System............................. 24

Alternator Assembly ............................................. 24

Brush Holder and Brushes .................................... 24

Other AC Generator Components .......................... 25

Section 2.2 – Operational Analysis....................................26

Startup................................................................. 26

On-Speed Operation.............................................. 26

Field Excitation...................................................... 26

AC Power Winding Output..................................... 26

Section 2.3 – Troubleshooting Flowcharts.........................27

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

Problem 1 – Generator Produces Zero Voltage

or Residual Voltage ............................................... 27

Problem 2 – Generator Produces

Low Voltage at No-Load........................................ 28

Problem 3 – Generator Produces

High Voltage at No-Load ....................................... 29

Problem 4 - Voltage and Frequency

Drop Excessively When Loads Are Applied............ 29

Section 2.4 – Diagnostic Tests..........................................30

Introduction .......................................................... 30

Safety................................................................... 30

AC Troubleshooting............................................... 30

Test 1 – Check Main Circuit Breaker ...................... 30

Test 4 – Fixed Excitation /Rotor Amp Draw Test ..... 30

Test 6 – Resistance Check of Rotor Circuit............ 32

Test 7 – Check Brushes and Slip Rings ................. 32

Test 9 – Test the Stator ......................................... 33

Test 10 – Test Rotor Assembly.............................. 34

Test 11 – Check AC Output Voltage....................... 34

Test 12 – Check AC Output Frequency................... 34

Test 13 – Adjust Engine Governor ......................... 35

Test 14 – Adjust Voltage Regulator ....................... 35

Test 15 – Check for Overload Condition................. 36

Test 16 – Check Voltage and

Frequency Under Load........................... 36

PART 3 – Transfer Switch ..................................................37

Section 3.1 – Description and Components.......................38

General................................................................. 38

Enclosure ............................................................. 38

EZ Transfer Operator ............................................. 38

Fuse Holder .......................................................... 38

Page 2

Section 3.2 – Operational Analysis....................................39

Utility Voltage Present ........................................... 39

Transfer to Standby............................................... 39

Transfer to Utility................................................... 39

Section 3.3 – Troubleshooting Flowcharts.........................41

Introduction .......................................................... 41

Problem 10 – In Automatic Mode,

No Transfer to Standby ......................................... 41

Problem 11 – In Automatic Mode, Generator

Starts When Loss of Utility Occurs, Generator

Shuts Down When Utility Returns But There is No

Retransfer To Utility Power OR Generator Transfers

to Standby During Exercise or in Manual Mode...... 41

Problem 12 – Blown F1 or F2 Fuse........................ 42

Problem 13 – Blown T1 Fuse ................................ 42

Problem 14 – Unit Starts and Transfer Occurs

When Utility Power is On....................................... 42

Section 3.4 – Diagnostic Tests..........................................43

Introduction .......................................................... 43

Safety................................................................... 43

Transfer Switch Troubleshooting .......................... 43

Test 27 – Check Generator Voltage at

Transfer Switch...................................... 43

Test 28 – Test Transfer Operator............................ 43

Test 29 – Check 15B/194 Circuit .......................... 43

Test 30 – Check Wire 23 Circuit ............................ 44

Test 32 – Check Fuses F1 and F2.......................... 44

Test 33 – Check N1 and N2 Wiring........................ 45

Test 35 – Check Fuse F3 ...................................... 45

Test 36 – Check T1 Wiring .................................... 45

Test 38 – Check N1 and N2 Voltage ...................... 46

Test 39 – Check Utility Sense Voltage.................... 46

Test 40 – Check Utility Voltage at Transfer Switch.. 46

Test 41 – Check Utility Sensing Voltage

at the Controller ..................................... 46

PART 4 – Engine/DC Control ..............................................49

Section 4.1 – Description and Components.......................50

General................................................................. 50

Terminal Strip / Interconnection Terminal ............... 50

Controller ............................................................. 50

Auto-Off-Manual Switch........................................ 50

7.5 Amp Fuse....................................................... 50

Alarms ................................................................. 52

Clear Alarms......................................................... 52

Warnings.............................................................. 52

Section 4.3 – Operational Analysis....................................54

Utility Source Available.......................................... 54

Utility Failure and Engine Cranking......................... 55

Utility Failure and Engine Running.......................... 56

Section 4.4 – Troubleshooting Flowcharts.........................57

Problem 20 – Engine Will Not Crank When

Utility Power Source Fails...................................... 57

Problem 21 – Engine Will Not Crank When

AUTO-OFF-MANUAL Switch is Set to “MANUAL” ... 57

Problem 22 – Engine Cranks but Won’t Start......... 58

Problem 23 – Engine Starts Hard and

Runs Rough / Lacks Power / Backfires.................. 59

Problem 24 – Shutdown Alarm/Fault Occurred ...... 60

Problem 25 – 7.5 Amp Fuse (F1) Blown................ 61

Problem 26 – Generator Will Not Exercise ............. 61

Problem 27 – No Battery Charge........................... 61

Section 4.5 – Diagnostic Tests..........................................62

Introduction .......................................................... 62

Safety................................................................... 62

Engine/DC Troubleshooting .................................. 62

Test 52 – Check Position Of

Auto-Off-Manual Switch ....................... 62

Test 53 – Try a Manual Start ................................ 63

Test 54 – Test Auto Operations.............................. 63

Test 55 – Check 7.5 Amp Fuse.............................. 63

Test 56 – Check Battery........................................ 63

Test 57 – Check Wire 56 Voltage........................... 65

Test 58 – Test Starter Contactor............................ 65

Test 59 – Test Starter Motor.................................. 66

Test 60 – Check Fuel Supply and Pressure ............ 67

Test 61 – Check Circuit Board Wire 14 Output ....... 68

Test 62 – Check Fuel Solenoid .............................. 69

Test 63 – Check Choke Solenoid ........................... 69

Test 64 – Check for Ignition Spark......................... 69

Test 65 – Check Spark Plugs ................................ 70

Test 66 – Check Engine / Cylinder Leak

Down Test / Compression Test............... 71

Cylinder Leak Down Test........................ 71

Check Compression............................... 71

Test 67 – Check Ignition Coil................................. 72

Test 68 – Check Oil Pressure Switch And Wire 86 . 72

Test 69 – Check High Oil Temperature Switch........ 73

Test 70 – Check and Adjust Valves........................ 74

Test 71 – Check Wire 18 Continuity....................... 75

Test 72 – Test Exercise Function ........................... 75

Test 73 – Test Cranking and Running Circuits........ 75

Test 74 – Test Run Circuit ..................................... 76

Test 75 – Test Crank Circuit .................................. 76

Test 76 – Check Battery Charger Supply Voltage.... 76

Test 77 – Check Battery Charger Output Voltage.... 77

Test 78 – Check Wire 0/15B.................................. 77

Test 79 – Check Shutdown Wire ........................... 77

Page 3

PART 5 – Disassembly.......................................................81

Section 5.1 – Major Disassembly......................................82

Section 5.2 – Exploded Views...........................................90

PART 6 – Electrical Data..................................................101

Wiring Diagram...............................................................102

Electrical Schematic ....................................................... 103

Electrical Formulas .........................................................104

Appendix A – Supplemental Worksheets..........................105

Appendix B – Index of Figures and Tables .......................109

Index of Figures ..............................................................110

Index of Tables................................................................111

Page 4

Specifications

GENERATOR

Rated Voltage 240

Rated Maximum Load Current (Amps) at 240 Volts (LP)* 29.2

Main Circuit Breaker 30 Amp

Transfer Switch Load Center Circuits** 30A, 240V 1

30A, 240V 1

20A, 120V 3

15A, 120V 3

Phase 1

Number of Rotor Poles 2

Rated AC Frequency 60 Hz

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

Weight (unit only in lbs.) 225

Enclosure Composite

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 areas

where temperatures fall below 32 °F (0 °C), a cold weather kit is highly recommended. When operated above 77º F (25º C) there may be a decrease in engine

power. (Please reference the engine specifications section).

These generators are rated in accordance with UL2200, Safety Standard for Stationary Engine Generator Assemblies; and CSA-C22.2 No. 100-04 Standard for

Motors and Generators.

* Natural Gas ratings will depend on specific fuel Btu content. Typical derates are between 10-20% off the LP gas rating.

** 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.

ENGINE

Type of Engine OHV-432

Number of Cylinders 1

Rated Horsepower @ 3,600 rpm* 14.8

Displacement 432cc

Cylinder Block Aluminum w/Cast Iron Sleeve

Valve Arrangement Overhead Valves

Ignition System Solid-state w/Magneto

Recommended Spark Plug RC12YC

Spark Plug Gap 0.76 mm (0.030 inch)

Compression Ratio 8.2:1

Starter 12 VDC

Oil Capacity Including Filter Approx. 1.1 Qts (1.0L)

Recommended Oil Filter Part # 0H9039

Recommended Air Filter Part # 0H6104

Operating RPM 3,600

* Engine power is subject to and limited by such factors as fuel Btu content, ambient temperature and altitude. Engine 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.



Caution: Specifications are for reference only, for actual installations always use the most recent version available online.

These specifications are subject to change without notice.

Specifications

Page 5

FUEL CONSUMPTION

Unit

Natural Gas* LP Vapor**

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

6/7 kW 66 119 0.82/30 1.47/53

* Natural gas is in cubic feet per hour. **LP is in gallons per hour/cubic feet per hour. Values given are approximate.

MAJOR FEATURES

Exhaust

Enclosure

Base Fuel Regulator

Battery

Fuel Inlet

Ground Lug

Oil Filter Data Label

(see sample)

Air Filter

Circuit Breaker

Control Panel

Page 6

Specifications

Page 7

Specifications

Page 8

NOTES

PART 1

GENERAL INFORMATION

Page 9