Cooper VR-32 Installation, Operation And Maintenance Instructions page 35

Figure 4-1.
Junction box wiring diagram.
E. Set the CONTROL switch on LOWER.
F. Measure the voltage between terminals L and G on ter-
minal board. The voltage reading should be approximate-
ly 120 volts act
G. If correct voltage readings are obtained in steps B and D
above, the trouble is in the regulator tank. Refer to trou-
bleshooting section of S225-10-2.
H. If there is no voltage measurement in either step B or D,
the problem is in the limit switches inside the position
indicator or the control cable.
7. Check the continuity of the raise and lower limit switches. The
switches should be closed on all tap changer positions except
for the set limit switch positions of the indicator dial. To check
the continuity:
A. Remove position indicator green-black lead from splice
terminals.
B. Place the meter lead on the disconnected lead and the
other lead on terminal L of the junction box terminal
board. Then check continuity.
C. If a continuity problem occurs, refer to Position Indicator
Replacement, on page 4-3.
D. Remove the position indicator blue lead from the splice
terminal.
E. Place the meter lead on the disconnected lead, and the
other lead on terminal R of the junction box terminal
board. Check continuity.
F. If a continuity problem occurs, refer to Position Indicator
Replacement, on page 4-3.
8. Check the reset solenoid of position indicator. Push the DRAG
HAND RESET switch while measuring the voltage between
DHR and G on the terminal board. The voltage reading should
be approximately 120 volts ac and DRAG HANDS will reset.
A. If 120 volts is read and drag hand will not reset, refer to
Position Indicator Replacement on page 4-3.
B. If 120 volts is not read; refer to Control Trouble Shooting,
on page 4-1.
Position Indicator Replacement
The following instructions apply only to the junction box
mounted position indicator construction that was initiated in
April, 1980.
To replace a defective position indicator requires removing
the unit from service as outlined in REMOVAL FRoM SER-
VICE on page 1-8.
1. A defect in the position indicator may have caused loss
of synchronization between the tap changer and the indi-
cator hand. Verify that the tap changer is in neutral via
the neutral light of the control and visual inspection of the
tap changer. If the position indicator does not also show
neutral, refer to instructions in S225-10-2, Spring-and-
Direct Drive Tap Changers.
2. Remove the junction box cover.
3. Note the location of the indicating hand for future align-
ment and disengage the flexible shaft from the position
indicator shaft.
A. In early 1986 this joint was changed to a set screw
type coupling.
B. Older equipment employed a cotter pin coupling.
4. Disconnect the four leads from the junction box terminal
board and open the two splice terminals to the control
cable.
5. Remove the three bolts holding the indicator to the junc-
tion box and slide the indicator free.
6. Remove the gasket from the groove on the back of the
indicator body.
7. Clean the gasket surface of the junction box and the gas-
ket and groove on the new indicator.
8. Place the gasket in the groove and insert the leads
through the junction box wall, align the holes and install
the three bolts finger tight.
9. Wrench-tighten the bolts to evenly compress the gasket
and bring the indicator body tight against the junction
box.
10. Connect the six leads to the terminal board and control
cable leads per Figure 4-1 and secure all connections.
11. Turn the indicator drive shaft to place the hand at the pre-
viously noted position.
12. Slide the flexible shaft coupling over the indicator shaft
and secure the joint.
13. Position the wire to prevent snagging on the coupling or
cotter pin. Secure with the wraps.
S225-10-5
4-2