TROUBLESHOOTING
TESTING AND ADJUSTING
TROUBLESHOOTING CHART INDEX
NO AC VOLTAGE
Item
Possible Cause
1.
Voltmeter Has a Defect.
2.
Open (Tripped) Thermal Protector (TP).
3.
Open Fuse (F1).
4.
Engine Low Idle rpm Too Low.
5.
Defect in Rotating Rectifiers (CR1 thru CR6):
C
Surge Suppression Diodes (CR7. 8); Exciter
Armature (L4); or Exciter Field (L3).
6.
Exciter Field (L3) is Open.
7.
Open or Short Circuit.
8.
Rounded Circuit.
9.
Loose Wire Connections.
10.
Wrong Regulator or Generator Connections.
11.
Shorted Rotating Rectifiers (CR1 thru CR6).
12.
Short Circuit in Field Rectifier (CR10).
13.
Loss of Residual Magnetism.
14.
Controlled Rectifier (CR9) Has a Defect.
15.
Rectifier Module (A2) Has a Defect.
16.
Regulator Module (Al) Has a Defect.
17.
Shorted Surge Suppression Diode (CR7 or
CR8).
18.
Shorted Surge Suppression Diode (CR11).
19.
Open Suppression Reactor (L1).
20.
Open SCR Reactor (L2).
21.
Shorted Suppression Capacitor (C2).
22.
Shorted RFI Suppression Capacitor (C1).
AC VOLTAGE TOO LOW
Item
Possible Cause
1.
Voltmeter has a Defect.
5.
Defect in Rotating Rectifiers (CR1 thru CR6);
C
Surge Suppression Diodes (CR7. 8); Exciter
Armature (L4): or Exciter Field (L3).
10.
Wrong Regulator or Generator Connections.
16.
Regulator Module (A1) Has a Defect.
23.
Open Rotating Rectifiers (CR1 thru CR6).
24.
Engine rpm Too Low.
25.
Load Too High or Not Balanced.
26.
Voltage Level Control Setting Too Low (R2).
27.
Voltage Droop Control Setting Too High (R1).
28.
Regulator Gain Control Setting Too Low
(R3).
AC Voltage Too Low (Cont.)
Item
Possible Cause
45.
Current in Exciter Field (L3) Is Not Stable.
46.
Defect in Voltage Level Rheostat (R2).
47.
Defect in Voltage Droop Potentiometer (R1).
48.
Rotor Winding (L5) Defect.
AC VOLTAGE TOO HIGH
Item
Possible Cause
1.
Voltmeter Has a Defect.
10.
Wrong Regulator or Generator Connections.
14.
Controlled Rectifier (CR9) Has a Defect.*
15.
Rectifier Module (A2) Has a Defect.*
16.
Regulator Module (A1) Has a Defect.'*
29.
Engine rpm Too High.
30.
Voltage Level Adjustment Too High (R2).
31.
Reverse Polarity on Voltage Droop Transformer
(T1).
32.
Regulator Gain Control Setting Too High
(R3).
33.
Open Regulator Gain Rheostat (R3).
34.
Open Field Rectifier (CR10).'*
35.
Load Not Balanced.
36.
Regenerative Load Power Too High.
37.
Open Regulator Power Resistor (R4 ).*
38.
Open Voltage Reference Circuit.
LACK OF AC VOLTAGE STABILITY
Item
Possible Cause
1.
Voltmeter Has a Defect.
4.
Engine Low Idle rpm Too Low.
9.
Loose Wire Connections.
14.
Controlled Rectifier (CR9) Has a Defect.
16.
Regulator Module (A1) Has a Defect.
32.
Regulator Gain Control Setting Too High
(R3).
33.
Open Regulator Gain Rheostat X R3).
39.
Lack of Load Stability.
40.
Too Much Vibration of Suppression Reactor
(L1).
41.
Lack of Engine rpm Stability.
42.
Damping Resistor Open (R5).
43.
Temporary Short Circuit in RFI Suppression
Capacitor (C1).
44.
Temporary Short Circuit in Suppression Ca-
pacitor (C2).
*This item can cause a condition of temporary high AC voltage. The result is normally permanent damage to
components. The secondary or visible condition is no AC voltage and an open fuse (F1).
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