Power Tech Generators PTS-25 Operator's Manual page 27

Zero
or
Low Voltage
Check
Main Breaker
On GenSet
Check
Gen End
One Coil
Low Voltage
Replace
Stator
VOLTAGE TEST
High
Voltage
Replace
AVR
12 VOLT
BATTERY TEST
Both Coils
Low Voltage
Check
Connections
Check Engine
RPM 1800
Replace Stator
Overload
Check AMP
Draw
From equipment
Check Load Distribution
One Voltage Line
may be
Higher than the other
Sensing Voltage
Low or None
Replace
Stator
6
Output
Voltage OK
Replace
AVR