S&C Vista® Underground Distribution Switchgear

Featuring
• Manual,
• Remote Supervisory, and
• Source-Transfer Models
S&C Vista®
Underground Distribution Switchgear
Outdoor Distribution, 15.5 kV through 38 kV
Vista Underground Distribution Switchgear Addresses Your Concerns
• Are you wasting money and resources on time- consuming, labor-intensive routine operation of your
switchgear?
• Has coordinating upstream protective devices with
downstream fusing become a headache?
• Are your customers complaining that they don’t want obtrusive green boxes on their property?
S&C’s Vista Underground Distribution Switchgear
is the answer to these and many other underground
distribution system problems. S&C worked closely
with electric utilities and power users to identify and
satisfy needs that were not being met by conventional
underground distribution equipment. Vista UDS is an
exceptional product that meets all of these needs.
Vista Underground Distribution Switchgear is available in manual, remote supervisory, and source-transfer models. All models feature loadinterrupter switches and resettable, vacuum fault
interrupters or arc spinners in series with disconnect
switches, elbow-connected and enclosed in a
submersible, SF6-insulated, welded steel tank. Vista
UDS is available with up to six “ways,” in ratings
through 38 kV and 25 kA symmetrical short-circuit.
Large windows in the tank provide a clear view of the
open gap, ground position, and ground bus.
Remote Supervisory Pad-Mounted Style Vista UDS installation.
2
Large viewing windows let you see
open gap and grounded positions
on load-interrupter switches and fault
interrupters. Trip indicators are easily
checked too
Operating panel is
located near grade level
so UnderCover™ Style
gear is easily operated
from a standing position.
See page 4
Overcurrent control—
readily programmed
with your PC
Fault interrupter
terminals—equipped
with 200-A bushing
wells, 600-A bushings,
or 900-A bushings
Optional voltage indicator with
liquid-crystal display. You can check
the integrity of the voltage indicator
by shining a flashlight on the photocell-powered test circuit, while placing
a gloved finger over the test button.
See page 8. No flashlight needed in
daylight
Switch terminals—equipped with
600-A bushings or 900-A bushings
Bushings and bushing wells are
located on one side of the gear,
reducing operating space required
for elbows and cables
15-kV UnderCover Style Model 422.
3
The load-interrupter switches provide three-pole
live switching of 600-ampere or 900-ampere three-phase circuits. The switches have three
positions (closed-open-grounded) and provide a
clearly visible gap when open. The 200-ampere,
600-ampere, and 900-ampere fault interrupters offer 40-ms fault clearing, have three-position (closed-open-grounded) disconnects, and are Optional voltage indicator with liquid-crystal
display. Includes self-test feature
Gas-fill port
Pressure gauge—(located
under window) temperature
and altitude compensated
available with either single-pole or three-pole
switching. Most models of Vista UDS use in-series
vacuum fault interrupters for fault clearing. However, the popular 15-kV, 12.5-kA manual models
now feature arc-spinning technology for fault
interruption . . . reducing the height of the tank by
nearly a foot!
Compact welded-steel tank protects
switching and protection components from
the environment. Stainless-steel construction
standard in UnderCover Style
Operating mechanisms
for switches and fault
interrupters—padlockable
in any position
Operation selector
prevents inadvertent
operation from “closed”
position directly to
“grounded” position and
vice versa
Microprocessor-based
overcurrent control
housed in watertight
enclosure. CTs (not visible)
provide power and signal
inputs
Operating panel of Vista UDS gear. Viewing windows, for confirming open gap and grounded position on loadinterrupter switches and fault interrupters, are located under hinged covers of voltage indicators.
4
Vista UDS is available in up to six “ways.” This
means it can accommodate any combination of up
to six bus taps, load-interrupter switches, or fault
interrupters. With conventional pad-mounted gear,
for a looped feeder with four taps, two units of gear
are necessary. But with Vista UDS, only one six-way
unit is needed. Vista UDS simplifies installation and
improves aesthetics by reducing the necessary real estate.
The model number indicates the total number of
ways, as well as the number of load-interrupter and
fault-interrupter ways. For example, Model 321 has
“3” ways—“2” load-interrupter switch ways and “1”
fault-interrupter way, as shown below.
Conventional
pad-mounted
gear
LOAD
1
LOAD
2
LOAD
3
LOAD
4
Vista
Underground
Distribution
Switchgear
LOAD
1
LOAD
2
LOAD
3
LOAD
4
TYPICAL CONFIGURATIONS OF MANUAL AND REMOTE SUPERVISORY VISTA UDS
201
321
422
514
624
TYPICAL CONFIGURATIONS OF SOURCE-TRANSFER VISTA UDS
V
T
V
T
V
T
V
T
321
523
V
T
V
T
532 (split-bus)
5
Vista UDS Offers Numerous Unobtrusive
Installation Options
One option is the low-profile pad-mounted style. At
15, 25, and even 34.5 kV, pad-mounted Vista UDS is 6
to 14 inches shorter than the average SF6-insulated
gear. And Vista UDS’s total real-estate requirement
is less than one-third that of a typical SF6-insulated
design. This means that Vista UDS is easier to site and
allows more room for landscaping options that further
improve aesthetics.
Vista UDS’s most innovative installation offering is
the UnderCover style. The UnderCover style is ideal
for areas with stringent real-estate restrictions or
where aesthetics are extremely important. The Vista
UDS gear is installed underground, but all operations
are easily performed by one operator above ground.
UnderCover style installations can also save money
by reducing costs associated with trenching and long
cable runs.
Vista UDS is also available for floor-mounted or
wall-mounted vault installations, and in a man-hole
style. With its compact design, rugged construction,
and internal visible open point, man-hole style Vista
UDS is perfect for applications where installation
space is limited.
UnderCover Style.
Pad-Mounted Style.
Vault-Mounted Style—available for floor and
wall-mounting.
Man-Hole Style.
6
Vista UDS Operation Is Quicker,
Easier, Safer
Vista UDS was specifically designed to simplify
operating tasks, enhance safety, and minimize the duration of outages. Vista UDS is certified arc-resistant per IEC 298 Appendix AA, for currents
up to 12.5 kA symmetrical for 15 cycles (25 kA
symmetrical for 15 cycles, for models rated 25 kA
short-circuit). In the event of an internal fault, the
enclosure will retain its integrity.
1.Rotate the switch operating shaft to the “open”
position, then confirm the open gap through the
large viewing window. See Figures 1 and 2. With
ordinary elbow gear, on the other hand, specially
trained operators need to remove the elbows from
their bushings using a shotgun clamp stick—a
tedious task that must be carefully performed. See
Figure 3.
Just one person is needed to operate Vista
UDS. There’s no exposure to medium voltage. The
procedure is simple:
“Grounded”
position
contact
Switch blade in
“open” position
“Closed”
position
contact
Figure 1. Opening load-interrupter switch (or fault
interrupter).
Vacuum bottle
Fault interrupter furnished on all Vista UDS except 15-kV
manual models.
Arc-spinning
contact
“Closed” position
contact
Switch blade
in “open”
position
Figure 2. Window cover lifts for viewing switch-blade
positions of load-interrupter switch or fault interrupter.
“Grounded”
position
contact
Fault interrupter furnished on 15-kV, 12.5-kA manual
models.
Figure 3. Operation of typical dead-front gear can be
awkward and time-consuming.
7
2. Confirm that the cable is de-energized so it can be
safely grounded. With traditional gear, the mediumvoltage cables must be tested directly using a clampstick-mounted tester. But voltage testing with
Vista UDS can be accomplished simply and easily
without ever accessing the cables. Simply use the
voltage indicators shown in Figure 4. The voltage
indicator is even equipped with a self-test function, so you can “test the tester.” See Figure 5.
3.Ground the cables. Instead of the awkward task of
having to move the elbows to parking stands, along
with the grounding bushings or elbows, with Vista UDS you need only rotate the switch operating shaft to the “grounded” position. See Figure 6. Grounding
can easily be confirmed by looking through the viewing window.
Test circuitry can be powered by
flashlight or bright sun
Place gloved finger over
test button to begin testing
Figure 5. Testing the voltage indicator.
There are even more benefits: The voltage indicator
can be furnished with a low-voltage phasing option.
See Figure 7. This feature allows confirmation of
proper phasing without ever accessing the cables.
Vista UDS allows fault-locating and hi-potting tests to be performed with the cables attached—and the
bus energized.
Photocell for
energizing selftest feature
Test button
Test window
LCD display
Figure 6. Grounding load-interrupter switch (or fault
interrupter).
Figure 4. Voltage indicator.
Figure 7. Measuring phase-to-phase voltage—Phase
1 to Phase 1.
8
Overcurrent Control
for Superior Coordination
Vista Tap
Interrupter (Phase)
Min. Pickup Current: 400A
Def. Time Delay: 4 cycle
TransformerPrimary Fuse
(100E, Standard
Speed)
100
TIME IN SECONDS
Phase
Overcurrent Relay
Type: CO-9
Time Dial: 3
Min. Pickup Current:
720A
CTI: 0.15 sec.
10
1
.1
100,000
10,000
1,000
100
.01
10
Vista UDS utilizes a unique microprocessor-based
overcurrent control, housed in a watertight enclosure mounted on the gear. The overcurrent control
features a variety of TCC (time-current characteristic)
curves with selectable instantaneous and definitetime delay attributes, for superior coordination with
upstream protective devices and downstream fusing.
The parameters for the TCC curves are set using a
personal computer connected to the data port of the
overcurrent control. There are no knobs or dials,
so the settings cannot be inadvertently changed or
altered by unauthorized personnel. Integral current
transformers provide power and current sensing.
There is even an event recorder that captures
information on the last twelve operations of each fault interrupter.
1000
CURRENT IN AMPERES
Coordinating-speed tap curve with definite-time
delay eliminates miscoordination problems
frequently encountered with transformer fuses.
User-supplied personal computer is attached to the overcurrent control for programming the relay in the field.
9
Remote Supervisory Vista UDS
For distribution automation applications, S&C offers
Remote Supervisory Vista UDS. Remote Supervisory
Vista UDS provides automated switching and fault
protection, and can also perform auto-sectionalizing
without tripping the main breaker. Automation
features are also retrofittable to existing Manual Vista
UDS. Motor operators, current and voltage sensors,
and low-voltage compartment are easily installed in
the field.
Position indicator
Operator
selector
Each motor operator includes a control board that
provides local push-button and remote operation
between the “closed,” “open,” and “grounded”
positions. Up to six control boards can be
accommodated within the low-voltage compartment,
so any or all load-interrupter switches or fault
interrupters can be motor operated. The motor
Details of motor operator.
15-kV Remote Supervisory Pad-Mounted Style Model 422.
10
Padlock feature
operators may be battery powered or, optionally, self-powered using internal voltage transformers. The low-voltage compartment may also contain
a user-specified remote terminal unit and
communication device, providing a completely
automated switching and protection package.
Optional voltage and current sensing round out the
Remote Supervisory Vista UDS offering.
A variety of RTUs have been successfully
integrated in Remote Supervisory Vista UDS,
including: ACS, Harris DART, Valmet PoleCAT, QEI/Quindar, Hathaway/Systems Northwest, Motorola MOSCAD, and DAQ.
And these transceivers have been integrated:
Metricom Utilinet, MDS, Dymec, H&L, and Motorola.
RTUs and communication devices of other
manufacture can be accommodated too; contact your
nearest S&C Sales Office.
Details of low-voltage compartment of Remote
Supervisory Vista UDS Model 422.
Position-indicating
lamps
Operation
push buttons
Push-to-test lamps
Connector for portable
motor operator control
Operation counter
Vista motor controls for installation with two motor-operated ways.
11
When Remote Supervisory Vista UDS is furnished
with an EnergyLine 5800 Series Switch Control, it can
be a member of an IntelliTEAM®, using EnergyLine’s
revolutionary peer-to-peer communications.
IntelliTEAM software supports automatic sectionalizing and reconfiguration, significantly
reducing outage time. IntelliTEAM’s peer-to-peer
communication network uses distributed intelligence,
eliminating the need for, but still fully supporting,
a SCADA master station. And, when Remote
Supervisory Vista UDS is fitted with an EnergyLine
switch control, the gear can be used for automatic
source transfer, with remote control and monitoring.
Remote Supervisory Vista UDS also allows the user
to remotely trip the vacuum bottles of any three-phase
fault interrupter way using external, user-specified
relays. This additional shunt-trip capability permits
advanced applications like sensitive earth-ground fault
detection, as well as protective relay schemes using
high-speed communication for closed-loop and openloop systems.
Portable Motor Operator
Local motor operation of Vista UDS gear is also
available for users who do not require a complete
automation package. The portable motor operator
includes cabling and hand-held control, all in an easily
portable, durable case.
Remote Supervisory Vista UDS with 5800 Series
Switch Control.
The operator easily attaches to any load-interrupter
switch or single-pole or three-pole fault interrupter.
Then simply plug in the power cable and the control
cable. The hand-held control features “open,” “close,”
and “ground” push buttons, an “enable” button
to prevent inadvertent operation, and a “ready”
indicating light.
Vista UDS Portable Motor Operator. Inset shows hand-held control.
12
Case for Vista UDS Portable Operator.
Source-Transfer Vista UDS
Source-Transfer Vista UDS provides fully automatic
primary-selective service for one, two, or three
critical load circuits. This package includes all
the features of Manual Vista UDS, plus the S&C
Micro-AT® Source-Transfer Control, three-phase
voltage sensing on source ways, and internal power
provided by voltage transformers. It is available in
common-bus and split-bus configurations. The Micro-AT Source-Transfer Control, located in
the low-voltage compartment, ensures a high degree
of critical-load continuity by minimizing interruptions
resulting from the loss of one source. Excluding the
intentional time delay to coordinate with upstream
protective devices and/or transition dwell time,
transfer is achieved in 6 seconds maximum.
The Micro-AT Source-Transfer Control utilizes
an advanced microprocessor to perform control
operations, as directed by settings programmed
into the device at the factory and in the field.
Such settings, consisting of the control’s operating
characteristics and voltage-, current-, and time-related
operating parameters, are entered into the control by
means of a keypad on the front panel.
An unbalance detection feature may be field-programmed in the Micro-AT Source-Transfer
Control. This feature protects the loads from any
source-side open-phase condition at the same voltage
as the Vista Underground Distribution Switchgear.
If the voltage unbalance exceeds a preset reference
level for a period of time sufficient to confirm that
the loss is not transient, an output signal is produced
which initiates automatic transfer to the other source.
An overcurrent-lockout feature may be furnished
which prevents an automatic transfer operation that
would close a source load-interrupter switch into a
fault. A light-emitting diode lamp indicates when
lockout has occurred. Test keys are provided for
simulating an overcurrent condition on each source.
Micro-AT Source-Transfer Control.
13
Standard Three-Phase Ratings123
Amperes, RMS
Fault Interrupter
Applicable
Standard
Frequency,
Hertz
Continuous,
Load
Dropping, and
Load Splitting
(Parallel or
Loop
Switching)
FaultClosing,
Sym.
Load-Interrupter Switch
Fault
Interrupting,
Sym.
Continuous,
Load
Dropping, and
Load Splitting
(Parallel or
Loop
Switching)
50 or 60
ANSI
50 or 60
Momentary,
Sym.
1 Sec.,
Sym.
ShortCircuit,
Sym.
Main Bus
Continuous
Current7
456
456
IEC
FaultClosing,
Sym.
200 or 630
12 500
12 500
200 or 630
12 500
12 500
12 500
12 500
600
630
25 500
25 000
630
25 500
25 000
25 000
25 000
600
200 or 630
12 500
12 500
200 or 630
12 500
12 500
12 500
12 500
600
600
25 500
25 000
600
25 500
25 000
25 000
25 000
600
1 Refer to the nearest S&C Sales Office for other ratings.
5 Fault interrupters and load-interrupter switches can switch the magne-
2 IEC ratings have been assigned in accordance with the applicable
tizing current of transformers associated with the load-dropping rating. In
addition, unloaded cable switching ratings are as follows: 10 amperes at
15.5 kV and 20 amperes at 29 kV and 38 kV.
portions of IEC 265-1 for a Class A switch.
3 ANSI ratings have been assigned in accordance with the applicable
portions of ANSI C37.71, C37.72, and C37.73.
4 Fault interrupters and load-interrupter switches are rated 600 amperes
(630 amperes IEC) continuous, load dropping, and loop splitting when furnished with 600-ampere bushings (standard for load-interrupter switches
and 25-kA fault interrupters, optional for 12.5-kA fault interrupters). The
rating is limited to 200 amperes if 200-ampere bushing wells are used
(standard for 12.5-kA fault interrupters, optional for 12.5-kA load-interrupter switches). Models rated 25-kA are only available with 600-ampere
bushings.
14
6 900 ampere is also available.
7 1200 ampere is also available.
 32,500-ampere peak ten-time duty-cycle rating.
65,000-ampere peak three-time duty-cycle rating. Ten-time duty-cycle
fault-clearing rating is 16,000 amperes symmetrical, 41,600 amperes
peak.

Printed in U.S.A.
Descriptive Bulletin
680-30
June 1, 20 04©
Offices Worldwide f www.sandc.com