Howard Voltage Regulators - Manual (Page 4)

SVR-1 Single-Phase Step Voltage Regulators
28-10
Copyright © 2011 Howard Industries, Inc.
4
Document No. 2.4.132
Revision: 0
Issued: October, 2011
Howard Industries, Inc.
Laurel, MS 39440
www.howardtransformers.com
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 Configure, DNP Point
Configure, 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 (first 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
finish.
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 full-
width aluminum strip conductor and
compression-bonded thermoset-
adhesive 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.
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
flexible 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
FIGURE 5: Tap changer mechanism
FIGURE 6: Tap position indicator