TROUBLESHOOTING
TESTING AND ADJUSTING
POSSIBLE CAUSES
VERIFICATION PROCEDURE
27. Voltage Droop Control Setting
Correct voltage at no load but low voltage under load at 0.8 power
Too High (R1)
factor, is an indication that voltage droop control (R1) setting is
too high. To make an adjustment, see Operation and Maintenance
Instructions. Check for good contact between the moving brush
and the turns of wire on voltage droop control potentiometer
(R1). Paint or other material can prevent good electrical contact
between these components. Bad contact will result in low voltage
from the generator under load at 0.8 power factor. You will not
get an adjustment in the voltage as the droop control is moved
from maximum to minimum setting.
28. Regulator Gain Control Setting
Correct voltage at no load but too low at rated load is an
Too Low (R3)
indication that regulator gain control (R3) setting is too low. See
Operation and Maintenance Instructions for adjustment procedures
29. Engine RPM Too High
Check engine rpm with a tachometer of high accuracy or with a
frequency meter. Make adjustments as needed to get correct
engine rpm.
30. Voltage Level Adjustment Too
Turn the voltage level rheostat (R2) toward minimum setting. See
High (R2)
Operation and Maintenance Instructions for adjustment.
31. Reverse Polarity on Voltage
Correct voltage at no-load but too high under load at 0.8 power
Droop Transformer (T1)
factor is an indication that the connections on voltage droop
transformer (T1) is wrong. Stop the engine and change the
connections of voltage droop transformer (T1) at terminals (5)
and (6). If this gives a correct high voltage under load, change the
numbers on wires from the transformer (T1).
32. Regulator Gain Control Setting
Correct voltage at no load but too high at rated load is an
Too High (R3)
indication that the voltage gain control (R3) setting is too high.
See Operation and Maintenance Instructions for adjustment.
Check for good contact between the moving brush and the turns
of wire on voltage gain control rheostat (R3). Paint or other
material can prevent good electrical contact between these
components. Bad contact will result in high voltage at rated load
and it will not be possible to get an adjustment when the control is
moved from maximum to minimum setting.
33. Open Regulator Gain Rheostat
Disconnect regulator gain rheostat (R3) by removing wire (lb) at
(R3)
spade terminal (8) of regulator module (A1). Check resistance
from wire (18) to spade terminal (7) on regulator module (Al).
With the regulator gain rheostat setting on maximum gain, the
resistance will be approximately 5000 ohms (500 ohms in units
with Al module that is black in color). When the gain control is
turned to minimum position the resistance will become less and
will read a short at the minimum position.
34. Open Field Rectifier (CR10)
Disconnect field rectifier (CR10) circuit by removing wire (8)
from terminal (F1). Use an ohmmeter or continuity checker
(8S4627). To check forward resistance of (CR10) put the positive
cable on terminal (F2) and the negative cable on wire (8). A low
resistance (10 ohms or less) on ohmmeter scale (RX1) or a light
with the continuity tester must be seen. If an open circuit
(infinity) or no light is seen field rectifier (CR10) is open. Remove
and install a new rectifier. For more information, see TESTING
POWER RECTIFIERS AND CONTROLLED RECTIFIERS.
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