Howard Industries’ SVR-1 single-phase
step voltage regulators are tap-changing
autotransformers designed to automatically regulate distribution line voltages in
a range of plus or minus 10% in thirty-two
steps of approximately 5/8% each. The
following ratings are available:
Internal potential winding taps and/or
an external ratio correction transformer
are provided on all ratings so that each
regulator may be applied within a range
of system voltages.
Catalog Section
Single-Phase Step
28-10
Voltage Regulators
A digital control system automatically
operates the tap changer mechanism to
maintain system voltage within desired
limits. The control system is externally
programmable to allow precise setting of
control limits and provides sophisticated
capabilities for special control requirements, communication, and data logging.
Overhead type voltage regulators are
supplied with support brackets for pole
mounting and have bolt-down provisions
for pad-mounted applications. Substation
type voltage regulators are provided with
rectangular substation bases. Elevating
platforms are available as an option.
SVR-1 voltage regulators are designed for
reliable operation and ease of maintenance and are supplied with a full array of
standard features for routine applications.
Optional accessories are available to accommodate special applications.
The SVR-1 features sealed-tank
construction and a 65°C rise insulation
system, which allows 55°C rise rated
designs to provide an additional 12%
capacity above nameplate rating
without loss of normal insulation
life. The HI-AMP™ feature provides
capability for additional load capacity,
as long as the regulator’s maximum
current rating is not exceeded.
The regulator’s complete internal
assembly (including tap-changer
switch, motor, core-and-coil assembly,
and reactor coil-and-coil assembly) is
mounted to the cover (Figure 2). This
construction simplies removal of
the internal assembly for inspection,
maintenance, and repair.
FIGURE 2: Internal Assembly
_______________________________
SVR-1 voltage regulators are designed,
manufactured, and tested in
accordance with the requirements of
ANSI Standard C57.15.
STANDARD REGULATOR FEATURES
All SVR-1 voltage regulators are
supplied with the following standard
accessories and features:
• Gear-driven tap-changer switch with
motor and power supply
• Motor capacitor mounted in control
enclosure for ease of replacement
• Mechanical tap position indicator
with externally adjustable HI-AMP™
limit switches
• Laser-etched nameplates (two)
• Lifting lugs
• Oil drain valve with sampling device
• Upper lter press connection
• Oil sight gauge
• High-creep porcelain bushings
• Bolt-down provisions (overhead type
regulators)
• Pole mounting brackets (overhead
type regulators)
• Rectangular substation base
(substation type regulators)
• Externally mounted series arrester
(MOV type)
• Mounting provisions for shunt
arresters
• Automatic pressure relief device
• Powder coated mild steel tank, cover,
clamp ring, and control enclosure
• HI/ICMI UVR-1 digital regulator
control (refer to description below)
OPTIONS
The following optional features and
accessories are available for the SVR-1
voltage regulator:
• Externally mounted shunt arresters
(MOV type)
• Wildlife protection for high-voltage
bushing terminals and lightning
arresters
• Extra-length control cable
• PTs and CTs for external metering
• Elevating platform
• Control enclosure heater
• 4-hole NEMA H-spade connectors
• Cooling fans
• Powder coated stainless steel
tank, cover, clamp ring, and control
enclosure
• HI/ICMI USC-1 simplied regulator
control
• Beckwith digital regulator control
• SEL digital regulator control
HI/ICMI UVR-1 CONTROL
The HI/ICMI UVR-1 digital regulator
control (Figure 3) has the following
standard features and options:
• Digital processing and nonvolatile
ash technology data storage with
Motorola 32-bit processor
• Super-bright LED indicators, including
High Band, In Band, Low Band, High
Limit, Low Limit, Voltage Reduction,
Reverse Power, Neutral Position, and
Alert
• Multiple, interoperable
communications ports, including
RS-232, IEEE-485 two and four-wire,
front panel serial program port, ber
optic interface, ethernet capable,
TCP/IP (optional), Bluetooth wireless
(optional), and eight-port input/output
board (optional)
• Certications: radio frequency
interference withstand capability per
ANSI/IEEE C37.90.2, electrostatic
(continued on Page 4)
FIGURE 3: HI/ICMI UVR-1 Control
Howard Industries, Inc.
Laurel, MS 39440
www.howardtransformers.com
Tank grounding provisions
(2)
Bolt-down provisions (4)
Howard Industries, Inc.
Laurel, MS 39440
www.howardtransformers.com
28-10
SVR-1 Single-Phase Step Voltage Regulators
discharge withstand capability
per IEC 61000-4-2 (1995-2001),
oscillatory surge and fast transient
surge withstand capabilities per ANSI
C37.90.1 (2002), metering accuracy
per IEEE C57.15 of 0.3% from -40°C
to +85°C (excluding VT/CT errors)
• User-friendly scrolling control
navigation with complete menu chart
(minimizes obsolescence)
• Comprehensive controller programs
on CD-ROM including Quick Start,
Control Congure, DNP Point
Congure, Data Log, Tap Contact Log,
and Program Loader, with customer
upgradeable expansion capability
• Front panel serial port
• Comprehensive control self-test
capability and protection safeguards
• Front panel controls including
automatic/manual motor control
switch, manual raise/lower switch,
drag-hand reset switch, local/remote
control switch, and internal/external
voltage source switch
• Panel-mounted fuses
• External voltage source terminals
• Voltage test terminals
• Line drop compensation R, X
• Temperature controller with settable
levels for high and low temperature,
-40°C to +85°C
• Sequential and time-integrating
regulation algorithms
• Reverse power capability without
need for internal potential
transformer
• Multiple modes of operation
including Locked Forward, Locked
Reverse, Idle Reverse, Bi-directional,
Neutral Reverse, and Co-generation
• Adjustable high and low-voltage limits
with automatic runback (rst house
protection)
REGULATOR CONSTRUCTION
SVR-1 regulators are designed and
built to provide reliable service, long
life, and ease of maintenance. The
entire internal assembly is mounted to
the regulator cover and can be easily
removed for inspection, repair, and
maintenance.
Tank
SVR-1 regulators feature sealed-tank
construction to prevent moisture and air
from entering the internal environment.
Tanks are constructed of mild steel
or stainless steel and electrostatically
coated with a tough polyester powder
nish.
Core and Coil Assembly
The use of a 65°C rise insulation
system in 55°C rated designs provides
an extra 12% capacity for the SVR-1
regulator without loss of insulation life.
The series coil is wound with fullwidth aluminum strip conductor and
compression-bonded thermosetadhesive insulation paper to provide
exceptional protection from potentially
damaging through-fault conditions.
Cores are manufactured from high
quality grain-oriented silicon steel.
Laminations are cut and assembled
using a distributed-gap process to
produce a low reluctance joint. A sturdy
clamping assembly effectively secures
the core and coils.
FIGURE 5: Tap changer mechanism
FIGURE 6: Tap position indicator
Tap Changer
All SVR-1 regulators feature rugged
gear-driven tap changers (Figure 5).
The tap-changing mechanism and
current-carrying contacts are designed
to provide exceptional reliability
and long service life exceeding one
million mechanical operations. The
tap changer uses an electric motor,
gear train, and spring drive to provide
quick, reliable operation. The switch is
mechanically coupled to the external
tap position indicator (Figure 6) to
provide visual indication of the switch
position.
Tap Position Indicator
The tap position indicator (Figure
6) is located on the cover-mounted
terminal block enclosure and is directly
connected to the tap changer by a
exible drive shaft. The indicator dial
plate is marked in 32 steps, 16 each
on the RAISE and LOWER segments of
the dial. The “zero” mark designates
the neutral position. Drag hands follow
the pointer and indicate the pointer’s
maximum and minimum positions since
the last reset. Drag hands can be reset
using the drag hand reset switch on the
front panel of the control unit. HI-AMP™
limit switches are mounted on either
side of the position indicator.
HI-AMP™ Feature
The HI-AMP™ Feature allows SVR-1
regulators to handle increased current
capacity by reducing the regulation
Howard Industries, Inc.
Laurel, MS 39440
www.howardtransformers.com
range. This is accomplished by setting
the raise (boost) and lower (buck) limit
switches (Figure 7) located on the tap
position indicator to prevent the tap
changer from traveling above or below
the desired settings. Scales on the
limit switches are graduated in percent
regulation, including 5%, 6-1/4%m
7-1/2%, 8-3/4% and 10% regulation
settings. Table 2 (Page 7) lists the load
current and regulation ranges available
with the HI-AMP™ feature. At each
setting, a detent stop provides positive
adjustment. Upper and lower limits
need not be the same.
Upper and lower limits can also be
implemented with the digital control
unit.
SURGE ARRESTERS
Series Arrester
Each SVR-1 regulator is equipped
with an appropriately sized MOV-type
surge arrester connected between the
source and load bushings (Figure 4).
This series arrester (also known as a
bypass arrester) is provided to protect
the series winding of the regulator from
damage due to line surges, such as can
result from lightning, switching surges,
and line faults. The series arrester
alone does not provide complete
lightning protection. For more complete
protection, option shunt arresters
should be installed.
Shunt Arresters
MOV surge arresters are available as an
option on the SVR-1 regulator to provide
protection for the shunt winding. Shunt
arresters are mounted on the regulator
tank adjacent to the load bushing and
the source bushing. Each arrester
is connected between the bushing
terminal and ground.
FIGURE 7: HI-AMP™ limit switches
(one located on each side of tap
position indicator)