TROUBLESHOOTING
TESTING AND ADJUSTING
POSSIBLE CAUSES
VERIFICATION PROCEDURE
35. Load Not Balanced
When the load on the generator cables (phases) is not the same
the load is not in balance and this can cause high voltage. Sensing
of the load on the generator is done from phase 1 to phase 2 and
from phase 3 to phase 2. If the lowest load is connected from
phase 1 to phase 3, the indicated generator voltage will be high.
36. Regenerative Load Power Too
In some applications the load on the generator will come from al
High
induction motor, used in lifting equipment. When a weight is
lowered with lifting equipment, the motor will work as
generator. The result of this condition is regenerative power going
to the electric set. The regenerative power will cause the electric
set to turn at too high rpm when:
1. There is no other load, or only a small other load on the set
2. When the lifting equipment has no dynamic brake.
With the electric set at too high rpm the output voltage will also
be too high.
37. Open Regulator Power Resistor
If regulator power resistor (R4) is open, a temporary high voltage
(R4)
will be the result. This will cause fuse (F1) to open. To check (R4)
disconnect wire (3) from spade terminal (3) on regulator module
(A1). Check resistance from wire (3) to terminal (26). Typical
resistance is approximately 1500 ohms.
38. Open Voltage Reference Circuit
If the voltage reference circuit is open, a temporary high voltage
will be the result. This will cause fuse (F1) to open. Disconnect
the voltage reference circuit by removing wires (20) and (22) from
terminals (20) and (22). Check resistance from wire (20) to wire
(22). Typical resistance is approximately 95,000 ohms. Check
resistance from wire (20) to terminal (24) and from wire (22) to
terminal (24). Typical resistance is approximately 65,000 ohm
for each circuit. For more information, see REGULATOR
MODULE.
39. Lack of Load Stability
Constant changes in load can cause a condition of variable speed
and voltage. Check load changes that vary at the same time.
40. Too Much Vibration of
Too much vibration of suppression reactor (L1) can loosen the
Suppression Reactor (L1)
coil-core assembly. A loose core can prevent stability of the
voltage.
41. Lack of Engine RPM Stability
When the voltage and engine rpm have no stability, the cause can
be either the voltage regulator assembly or the engine (governor)
To find the cause, disconnect the voltage regulator assembly from
the engine. A separate source of DC excitation is needed. The
separate DC source can not be over 24 volts (batteries can be used
and must have a manually controlled rheostat in series with the
negative lead of the source. The rheostat is needed to give
protection to the exciter field from too much current. Stop the
engine and disconnect wires (F1) and (F2) from terminals (F1
and (F2). Connect the positive cable "+" from the DC source to
wire (F1). Turn the series rheostat to maximum resistance less
than five volts). Connect the negative cable "-" to wire (F2).
Start the engine and run at rated rpm. Look at the AC voltmeter
and turn the rheostat to add to the excitation voltage from the
batteries until the AC voltmeter gives an indication of rate,
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