11 .
With the voltmeter still connected to
Tb
1
-L
1
to
G
, give
a
Raise
signal.
12 .
The voltmeter should read a capacitive voltage plus run
voltage. This voltage could be somewhere between
160 and 190 V ac.
13 .
A voltage reading on
Tb
1
-L
1
to
G
of 0 V, or a mV read-
ing, is a sign of a bad capacitor.
14 .
If both the raise and lower circuit reads 0 V or a mV
reading, when there should be a capacitive voltage
plus run voltage, then the motor capacitor is open. The
capacitor will need to be replaced.
Operation Counter Does Not Indicate Tap
Change
If the operation counter does not indicate tap changes,
check the following:
.
The voltage signal at
Tb
2
-R
3
and
L
3
should be approxi-
mately 120 V when a tap change is made. When this
voltage signal is applied, the control panel operation
counter will be updated.
2 .
Measure the voltage at
Tb
2
-R
3
or
L
3
when the tap-
changer is given a command to tap in manual mode by
the
Raise/Lower
toggle switch. If the voltage signal
is present, the problem is either in the control connec-
tor or the control.
3 .
If the voltage signal is not present at
Tb
2
-R
3
or
L
3
,
the problem could be in the back-panel wiring har-
ness connections at
Tb
1
-R
1
or
L
1
, the control cable,
junction box connections, or the holding switch on the
tap-changer.
4 .
Check the voltage signal at
Tb
1
-R
1
or
L
1
. If the signal
is not present at these points, keep tracing the signal
back through the components back into the regulator.
Tap Position Out-of-Sync
If the control (FC 12, Present Tap Position) loses sync with
the position indicator, check FC 49, Tap-Changer Type
against the nameplate on the regulator. The nameplate
indicates what type of tap-changer is on the Cooper
Power Systems regulator. FC 49 must be set for the type
of tap-changer (Spring Drive, Direct Drive, QD-8, QD-5, or
QD-3).
Regulator Will Not Tap Beyond a Certain Tap
Position
If the regulator will not tap beyond a certain tap position,
check the limit switch settings on the position indicator.
If the limits need to be adjusted, adjust upper and lower
limits to allow proper regulation.
Regulator Operates Manually but
Operates Incorrectly When Set On
Automatic
Run the regulator to the neutral position with the control
switch. Check for voltage between
V
4
and
G
on
Tb
1
. This
is the sensing circuit supplying voltage from the output of
RCT
1
on the rear panel. If this voltage is more than 10%
above or below the programmed voltage-level setting of
the control, then the source is beyond the range of the
regulator. An absence of voltage would indicate a wiring
problem such as an open somewhere in the control power
supply. If these voltage checks are within range, perform
the following:
.
Verify that the band edge indicators are functioning.
(These are the
Out-of-band High
and
Out-of-band
Low
indicators located on the front panel.) If they are
not functioning, check FC 56, Reverse Sensing Mode.
Set it to
Locked Forward
if it is set for another option.
Verify the automatic mode of operation.
2 .
Verify that Function Code 69, Auto Blocking is set to
Norma
l. Verify the automatic mode of operation.
3 .
Measure the voltage from
V
S
to
G
on lower terminal
board
Tb
2
.
A .
A measurement of approximately the set voltage
value at
V
S
to
G
indicates that the problem is in the
control.
B .
If there is no voltage present at
V
S
to
G
, the trouble
is in the
V
1
disconnect or the ratio-correcting trans-
former of the back-panel circuit. Replace them.
4 .
Check the holding switch circuit.
A .
Verify that the tap-changer will complete a tap
change by placing the CONTROL FUNCTION
switch to
Manual
and toggling the
Raise/Lower
switch in the desired direction.
B .
If the
Raise/Lower
switch must be held in the
Raise
or
Lower
position to complete a tap
change, the problem is in the holding switch circuit.
If the holding switch is not working, a Quik-Drive
tap-changer will do multiple taps until the control-set
time delay expires.
C .
Check for voltage between
Tb
2
-H
S
and
G
and
Tb
1
-H
S
and
G
. If voltage is present at
Tb
1
-H
S
and
not on
Tb
2
-H
S
, the problem is in the back panel
wiring harness. Replace the orange
H
S
lead from
Tb
1
-H
S
to
Tb
2
-H
S
. If no voltage is present at
Tb
1
-
H
S
, the problem is in the control cable, junction
box cover, or the holding switch (located inside the
regulator) itself. Check cable continuity up to the
junction box. If it appears normal, the problem is
the holding switch. Adjust or replace it (see
Service
Information S225-10-2
or
S225-10-19
). If all
appears to be in order, the problem is most likely in
the control, not in the holding switch.
VR-32 Voltage Regulator Installation, Operation, and Maintenance Instructions
30
