Internal Constructlon; Wiring Diagrams - Cooper VR-32 Installation, Operation And Maintenance Instructions

VR-32 Regulator and CL-2A Control
INTERNAL CONSTRUCTION &

WIRING DIAGRAMS

The main core-and-coil assemblies are of the shell-form con-
figuration. The series winding on the input (source) side of the
regulator (Figure 1-9) allows all windings (control, shunt, and
series) to be located in one coil. The load voltage is read
directly by the control winding.
Regulators that have the series winding on the output (load)
side (Figure 1-10) possess an identical coil configuration, but
have a separate potential transformer in lieu of a control wind-
ing installed on the output side. This voltage is then applied to
the sensing circuit of the control.
The control winding is wound on the core to obtain a supply
voltage for the tap changer motor and the control sensing cir-
cuits. Taps are available on this winding for large-step voltage-
ratio correction.
The shunt winding is wound over top of the control winding
with the series winding wound over top of the shunt winding.
Most regulators, depending upon the rating, have an equalizer
winding. If applicable, the equalizer winding is wound on the
outside of the coil over the series winding.
Figure 1-11 shows a regulator power circuit with a series
transformer. This design is utilized when the load current rating
exceeds the tap changer rating. Figure 1-12 shows the internal
construction of this regulator. In this type of design, the series
transformer winding losses are a function of the load alone
and are independent of the tap position. Because of this, limit-
ing the range of voltage regulation does not reduce losses
Figure 1-9.
Power circuit - series winding located on the source-side.
(ANSI Type B)
1-10
and therefore, the ADD-AMP feature is not applicable.
The preventive auto or bridging reactor is a core-form design,
consisting of a coil on each leg of the core. The inside half of one
coil is connected to the outside half of the other coil and vice
versa, providing equal current in each half of the reactor winding.
This interlacing of the two coils reduces the interwinding leakage
reactance to a very low value. The reactor is completely isolated
from ground by stand-off insulators since the reactor coil is at
line voltage above ground. The reactor core, core clamps, and
other associated parts approach this level.
The current transformer is a toroid, through which the load cur-
rent passes. It furnishes a current proportional to load current to
the line-drop compensator circuit in the control and to optional
metering packages.
The tap changer enables the regulator to provide regula:ion in
smooth, accurately proportioned steps at a controlled speed that
minimizes arcing and extends contact life. Four different tap
changers are used throughout the line of regulator ratings.
Figures 1-13 through 1-16 illustrate typical internal wiring
schemes of the various types of regulator constructions. Most of
the wiring is on the tap changer itself. Application, troubleshoot-
ing, and operation of the spring- and direct-drive tap changers
and related components are covered extensively in Service
Manual S225-10-2.
The terminal board inside the junction box on the cover con-
nects the internal tank wiring to the position indicator and con-
trol. The junction box wiring is shown in Figure 4-1, page 4-2.