Generac Power Systems 8 kW LP - Manual (Page 33)

Page 31
air-cooled, automatic
standby Generators
Part 2
ac GENErators
taBlE of coNtENts
Part titlE PaGE#
2.1. Description and components 30
2.2 operational analysis 33
2.3 troubleshooting flow charts 35
2.4 Diagnostic tests 39
2.1 Description and Components .......................... 32
Introduction ......................................................32
Engine-Generator Drive System ......................32
The AC Generator ............................................32
Rotor Assembly ................................................32
Stator Assembly ...............................................33
Brush Holder And Brushes (12-20 kW) ...........34
Other AC Generator Components ...................34
2.2 Operational Analysis ....................................... 35
Rotor Residual Magnetism...............................35
Field Boost (12-20 kW Units) ..........................35
Operation (8/10 kW) .........................................36
Operation (12-20 kW) ......................................36
2.3 Troubleshooting Flowcharts ............................. 37
Problem 1 – Generator Produces Zero
Voltage or Residual Voltage 12-20 kW .... 37-38
Problem 2 – Generator Produces Zero
Voltage or Residual Voltage 8/10 kW ............38
Problem 3 – Generator Produces
Low Voltage at No-Load ................................39
Problem 4 – Generator Produces
High Voltage at No-Load ...............................39
Problem 5 – Voltage and Frequency Drop
Excessively When Loads are Applied ...........40
2.4 Diagnostic Tests .............................................. 41
Introduction ......................................................41
Safety ............................................................41
Test 1 – Check Main Circuit Breaker ................41
Test 2 – Check AC Output Voltage ...................41
Test 4 – Fixed Excitation Test/Rotor
Amp Draw Test ....................................42
Test 5 – Wire Continuity (12-20 kW) ................43
Test 6 – Check Field Boost (12-20 kW) ...........44
Test 7 – Testing The Stator With A Vom
(12-20 kW)...........................................44
Test 8 – Test Brushless Stator..........................45
Test 9 – Check Capacitor .................................46
Test 10 – Test DPE Winding on
Brushless units ....................................47
Test 11 – Resistance Check Of Rotor Circuit
(12-20 kW)...........................................48
Test 12 – Check Brushes And Slip Rings
(12-20 kW)...........................................48
Test 13 – Test Rotor Assembly(12-20 kW) .......49
Test 14 – Check AC Output Frequency ............49
Test 15 – Check and Adjust Engine Governor
(Single Cylinder Units) .........................49
Test 16 – Check Stepper Motor Control
(V-twin Engine Units) ...........................50
Test 17 – Check And Adjust Voltage
Regulator (12-20 kW) ..........................51
Test 18 – Check Voltage And Frequency
Under Load..........................................52
Test 19 – Check For Overload Condition ...........52
Test 20 – Check Engine Condition ...................52
Test 21 – Field Flash Alternator (8-10 kW) ......52