Part 4 - Engine/Dc Control - Generac Power Systems 7 kW NG Repair Manual

PART 4
ENGINE/DC
CONTROL
Air-cooled, Automatic
Standby Generators
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
Initial Dropout of Utility Source Voltage ..................................................... 98
Utility Voltage Failure and Engine Cranking .............................................. 100
Engine Startup and Running ................................................................... 102
Transfer to Standby ............................................................................... 104
Utility Voltage Restored and Re-transfer to Utility .................................... 106
Engine Shutdown................................................................................... 108
Section 4.4 - Troubleshooting Flowcharts ...............................................................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
TABLE OF CONTENTS
SECTION TITLE
4.1 Description and Components
4.2 Engine Protective Devices
4.3 Operational Analysis
4.4 Troubleshooting Flowcharts
4.5 Diagnostic Tests
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 ......................................... 137
Test 67 - Test Run Circuit ...................................................................... 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 ...................................................... 139
Test 71 - Check operation of the Choke Solenoid ................................... 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 ...................................................... 140
Test 78 - Test DC Charge Current to the Battery ..................................... 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 ....................................... 141
Test 82 - Test F3 Fuse Circuit ................................................................ 142
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