1-8
VR-32 Regulator and CL-4C Control
WARNING: Closing the bypass switch with the
tap changer off neutral will short circuit part of the
series winding. Before closing the bypass switch, the
regulator must on NEUTRAL and the control switch set
to OFF.
WARNING: A regulator should be bypassed with
the line energized ONLY if BOTH the position indi-
cator AND the neutral light indicate NEUTRAL. If both
do not indicate NEUTRAL, the line should be de-ener-
gized to avoid shorting part of the series winding.
WARNING: Always use the CONTROL switch
(labeled AUTO/REMOTE-OFF-MANUAL) to oper-
ate the regulator, not the POWER switch. Failure to do
so may result in the tap changer stepping off of neutral
immediately upon being energized.
Operational Check
NOTE: This operational check on the control should be used only
with newly installed regulators. For regulators already on-line, use
the operational check on page 2-3. With the CL-4C control now set
for basic operation, an operational check should be performed as
follows:
1. Depress the “8” key to display the COMPENSATED
VOLTAGE.
2. Place the Control Switch in the MANUALposition.
3. Lift up on the RAISE switch to activate a raise operation.
4. Allow the tap changer to operate for five or six steps, or enough
steps to take the voltage above the in-band voltage level.
5. Now place the Control Switch in the AUTO position. After the
time delay period, the control should cause the regulator to step
down to within the top band edge. (Example: 120V and a 2V
B.W. = 121 V top band edge). This should be shown in the
display.
6. After the voltage is brought in-band and tap changing has
stopped, move the Control Switch to the MANUALposition.
7. Press down on the LOWER switch to activate a lower opera-
tion.
8. Allow the tap changer to operate five or six steps, or enough
steps to take the voltage below the in-band voltage level.
9. Now place the Control Switch in the AUTO position. After the
time delay period, the control should cause the regulator to
step up to within the lower band edge. [Example: 120V and a
2V B.W. = 119V lower band edge). This should be shown in
the display.
This concludes the operational check of the CL-4C control and
regulator.
FIELD CALIBRATION CHECK
If the operator also desires to check the calibration of the control,
perform the steps listed below. NOTE: field calibration checks are
only an indication of calibration, and are not nearly as precise as
the procedure described in the CONTROLTROUBLE SHOOTING
section of this manual, which is a laboratory process.
1. Connect an accurate true-RMS responding voltmeter (such as
the Fluke 8026B, 8060A, or 8062A multimeters) to the VOLT-
METER terminals.
2. The easiest and most direct way to perform a calibration check
is to compare the voltage that the control “sees” to the voltage
measured at the test terminals. This is accomplished by
accessing the keypad and keying
FUNCTlON, 47, ENTER.
3. Under ideal conditions, the displayed voltage of the control will
match the voltage of the voltmeter. Realistically, the voltages
may be slightly different because:
A) The CL-4C metering and operation is based upon the RMS
value of the 60 Hz power line frequency. Thus, the metered
values exclude the influences of harmonic voltages which
are probably present on the line. Atrue-RMS meter however,
will include these harmonic voltages in its calculation of the
RMS voltage. This does not represent a problem with either
metering device, since each device uses a different
approach to metering.
B) The calibration of the voltmeter being used for measurement
is probably not exact. Even a very good meter with a basic
accuracy of 0.5% could be in error by as much as 0.6V (out
of 120V), and still be considered to be “incalibration.” The
CL-4C control is calibrated using a conditioned power supply
and reference voltmeters which are periodically calibration
checked, traceable to the National Bureau of Standards.
NOTE: The CL-4C control is designed to perform ratio correction
in software. Through the use of the ratio correcting transformer
(RCT) located on the back panel, the voltage brought to the front
panel is usually already corrected to the 120-volt base voltage.
However, there are some ratings in which this voltage is not fully
corrected by the RCT. Column 6 in Table 2-1, page 2-4 gives a
general indication of these voltages, but always refer to the
nameplate which provides the specific information for the particu-
lar regulator.
The voltage displayed at Function Code 8 (compensated voltage)
is the voltage which the control is regulating. This value takes into
consideration the software ratio correction and any line drop com-
pensation being used. Additionally, if the regulator is equipped for
reverse power operation, the voltage displayed at Function Code
8 will be correct even during reverse power conditions. The volt-
age measured at the test terminals, however, will reflect the input
(SOURCE) voltage instead of the output (LOAD) voltage.
REMOVAL FROM SERVICE
Determining Neutral Position
Return the regulator to neutral. The regulator can be safely
removed from service without interrupting load continuity only
on the neutral position. It is wise to employ more than one
method to determine whether a regulator is on neutral.
To Return The Regulator To Neutral
1. Use the control to RAISE or LOWER the regulator until it is
in the neutral position.
2. When on NEUTRAL, the NEUTRAL LAMP will light and the
POSITlON INDICATOR will point to zero.
3. To stop the regulator on the neutral position, the CONTROL
switch should be turned to OFF during the switching opera-
tion from position “1 “ to position zero. Switching to OFF
prior to reaching the neutral position prevents overshoot.
4. The POSITlON INDICATOR and NEUTRAL LIGHT MUST
BOTH indicate neutral.