Part 2 - Ac Generators - Guardian 5240 Diagnostic Repair Manual

PART 2
AC GENERATORS
Air-cooled, Prepackaged
Automatic Standby
2.1 Description and Components .......................... 30
Introduction ......................................................30
Engine-generator Drive System .......................30
The AC Generator ............................................30
Rotor Assembly ................................................30
Stator Assembly ...............................................31
Brush Holder And Brushes ..............................31
Other AC Generator Components ...................31
2.2 Operational Analysis ....................................... 33
Rotor Residual Magnetism...............................33
Field Boost .......................................................33
Operation .........................................................34
2.3 Troubleshooting Flowcharts ............................. 35
Problem 1 - Generator Produces Zero
Voltage or Residual Voltage .......... 35-36
Problem 2 - Generator Produces
Low Voltage at No-Load ......................37
Problem 3 - Generator Produces
High Voltage at No-Load .....................37
Problem 4 - Voltage and Frequency Drop
Excessively When Loads are Applied .38
2.3 Diagnostic Tests .............................................. 39
Introduction ......................................................39
Safety ............................................................39
Generators
TABLE OF CONTENTS
PART TITLE
2.1. Description and Components
2.2 Operational Analysis
2.3 Troubleshooting Flow Charts
2.4 Diagnostic Tests
Test 1 - Check Main Circuit Breaker.................39
Test 2 - Check AC Output Voltage ....................39
Test 4 - Fixed Excitation Test/Rotor
Amp Draw Test ....................................40
Test 5 - Wire Continuity ....................................41
Test 6 - Check Field Boost ...............................42
Test 7 - Testing The Stator With a VOM ...........42
Test 8 - Resistance Check of Rotor Circuit ......44
Test 9 - Check Brushes and Slip Rings ............44
Test 10 - Test Rotor Assembly .........................45
Test 11 - Check AC Output Frequency.............45
Test 12 - Check And Adjust Engine Governor
(Single Cylinder Units) .........................46
Test 12A - Check Stepper Motor Control
(V-twin Engine Units) ...........................46
Test 13 - Check And Adjust
Voltage Regulator ................................48
Test 14 - Check Voltage And
Frequency Under Load ........................48
Test 15 - Check For Overload Condition ..........48
Test 16 - Check Engine Condition ....................48
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