GE prolec VR-1 Installation, Operation And Maintenance Manual page 32

Trouble
Reversed
Regulator polarity in either
bucks the current
when load transformer
increases or potential
transformer
Shorting switch is
LDC On/Off
switch in OFF
Line-drop
position
compensator
is not
functioning
in either
reactance or
resistance or
R65 or T3 is
both
defective
Line drop
Defective LDC
compensator
circuit board
is not
functioning
in either
Defective
reactance or
current
resistance or
transformer
both.
Motor or motor
Motor does
capacitor may
not operate
be faulty.
prolec.energy/prolecge
Cause
Reverse the current transformer leads in the control cabinet by disconnecting
leads NN24 and NN23 (at the terminal board) and reversing the connections.
Warning: Short-circuit the current transformer so the secondary will not become
open-circuited. (The current transformer is short-circuited automatically by
removing the control-cable plug from the bottom of the position-indicator
housing.)
Remove the position-indicator plug and check the shorting pin for physical defects.
If it is defective, replace it. If the shorting pin is normal, reconnect the position-
closed indicator plug and secure it tightly to be sure the shorting pin is disengaging the
Disconnect the position-indicator control plug form the bottom of the position-
indicator housing; then disconnect the harnessed red nine-point connector-plug
between the control panel and the circuit component board.
Warning: Short-circuit the current transformer secondaries. If left open-circuited,
current transformers develop secondary voltages hazardous to personnel. The
current transformer is short-circuited automatically when the control-cable plug
is removed from the bottom of the position-indicator housing.
Check the primary resistance of T3 by measuring with an ohmeter across pins
number 3 and 4 in the red plug going to the front of the panel. The LDC On/Off
switch should be in the ON position. The reading should be 2.8 ohms ± 1.
Check the secondary winding of T3 by measuring with an ohmeter across
terminals number 3 and 4 on the transformer. The reading should be 16 ohms ±
5.
Proceed as indicated in Trouble III, 2.
Trouble-shoot control with test set-up as indicated under "Calibration". Refer to
control theory for explanation of circuit.
If all components in 1, 2, 3 and 4 are normal, but no compenation exists, a
defective current transformer is the probable cause.
1. Disconnect the four (4) leads from the capacitor terminals, apply 240 volts,
60 hertz to the terminals. Read the current in the line. This reading should be
approximately 0.36 amperes.
Caution: Discharge the capacitor before reconnecting the leads.
2. Reconnect the capacitor, and apply 120 volts directly to the motor. Refer to
control diagram for connections
GEH-7299A: Installation, Operation and Maintenance Manual
for Type VR1™ Single-Phase, Step Type Regulators
Remedy
shorting jack.
Set switch to ON position
32