Generac Power Systems 16 kW NG User Manual

Page 31

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