Power Tech Generators PTS-30 Operator's Manual page 168

Unbalanced voltages indicate a fault on the main stator winding or main cables to the circuit breaker.
These faults may also cause noticeable load increase on the engine.
Disconnect the main cables and separate the winding leads U1-U2, (U5-U6), V1-V2, (V5-V6), W1-W2,
(W5-W6) to isolate each winding section.
Frame Size
AG164A
AG164B
AG164C
AG164D
AG184E
AG184F
AG184G
AG184H
AG184J
AG224C
AG224D
AG224E
AG224F
AG224G
AG274C
AG274D
AG274E
AG274F
AG274G
AG274H
AG274J
AG274K
All models of automatic voltage regulators can be tested as follows:
1. Remove exciter field leads X & XX (F1 & F2) from the AVR terminals X & XX (F1 & F2).
2. Connect a 60W 240V incandescent bulb to AVR terminals X & XX (F1 & F2).
3. Turn the AVR VOLTS control potentiometer fully clockwise.
4. Connect a 12V; 1.0A DC supply to the exciter field leads X & XX (F1 & F2) with X (F1) to the positive.
5. Start the generating set and run at rated speed.
6. Check that the generator output voltage is within +/- 10% of rated voltage.
The bulb should light for approximately 8 seconds and then turn off. Failure to turn off indicates a faulty
protection circuit and the AVR should be replaced. Turning the "VOLTS" control potentiometer fully
counter-clockwise should turn off the lamp with all AVR types. Should the bulb fail to light, the AVR has
failed and should be replaced.
AVR CONTROLLED GENERATORS
Section Frame Size
Resistance
0.81 AG4C
0.51 AG4D
0.36 AG4E
0.30 AG4F
0.20 AG5C
0.13 AG5D
0.11 AG5E
0.085 AG5F
0.074 AG6G
0.09 AG6H
0.065 AG6J
0.05 AG6K
0.033
0.028
0.03
0.019 AG162D
0.016 AG162E
0.012 AG162F
0.01 AG162G
0.008 AG182H
0.006 AG182J
0.006 AG182K
Section
Resistance
0.0083
0.0062
0.0045
0.0037
0.0033
0.0025
0.0022
0.0019
0.0017
0.0013
0.0011
0.0085
0.68
0.42
0.31
0.21
0.16
0.13
0.10
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