TROUBLESHOOTING
TESTING AND ADJUSTING
POSSIBLE CAUSES
VERIFICATION PROCEDURE
(Continued)
removed to the spade terminal that wires (26) are connected.
When the ohmmeter test cables are first connected to the
capacitor, a low resistance will be seen. As a charge from the
ohmmeter is put on the capacitor, the resistance will go up until a
constant indication of near infinite resistance is seen.
23. Open Rotating Rectifiers (CR1
Disconnect the rotating rectifiers (CR1 through CR6) by removing
through CR6)
the wires from exciter armature (L4) at the connections of each
rectifier. Use an ohmmeter or continuity tester (8S4627) and put
the negative cable to positive heat sink (E1) and positive cable to
the terminal (anode) of each rectifier (CR1, CR2 and CR3). A low
resistance (10 ohms or less) on ohmmeter scale (RX1) or a light
with continuity tester (8S4627) must be seen. if not, the rectifier
is open and must be changed.
Put the positive cable of the ohmmeter or continuity tester on the
negative heat sink (E2) and the negative cable on the terminal
(cathode) of each rectifier (CR4, CR5 and CR6). A low resistance
(10 ohms or less) on ohmmeter scale (RX1) or a light with the
continuity tester must be seen. If not, the rectifier is open and
must be changed. For more information, see subject, TESTING
POWER RECTIFIERS AND CONTROLLED RECTIFIERS.
24. Engine RPM Too Low
Check the engine rpm with tachometer of high accuracy or with E
frequency meter. Make adjustments to the governor as needed to
get correct engine rpm.
25. Load Too High or Not Balanced
Measure the load in amperes for each phase of the generator. The
ampere load must not be higher than the rating given on the name
plate of the generator. If necessary, make the load smaller. Toc
high load on the engine (too many kilowatts) with low voltage car
be caused by a high power factor. If the power factor is near 0.3
to 1.0, a reduction of the load must be made. Make this reduction
to 80% of the rating In amperes. Too much load on the generator
(too many kilovolt amperes) and low voltage can be caused by
low power factor. If the power factor is less than 0.8, a reduction
in the load is necessary.
When the load between the phases of the generator is not in.
balance, low voltage can be the result. Sensing of the load on the
generator (voltage sensing) is done from phase 1 to phase 2 and
from phase 3 to phase 2. If the highest load is connected from
phase 1 to phase 3 the indicated generator voltage will be low.
26. Voltage Level Control Setting
Get the voltage level higher by making an adjustment of voltage
Too Low (R2)
level control (R2). See Operation and Maintenance Instructions.
Check for good contact between the moving brush and the turns
of wire on voltage level rheostat (R2). Paint or other material car:
prevent good electrical contact between these components. Bad
contact will result in low voltage when it is not possible to get an
adjustment of the voltage level when moving the voltage level
rheostat (R2) from the maximum to minimum setting.
67
