1. INTRODUCTION
1.1 general system description
1.1.1 Medium-voltage switchgear
The SVS/12 system is a metal encapsulated, epoxy resin
insulated switchgear system with permanently integrated
vacuum contact breakers. The system is suitable not only
for electricity companies, but also for industrial and utility
connections.
The system is suitable for the medium voltage range, in
other words for nominal voltages up to a maximum of 24 kV
and nominal currents up to a maximum of 1250 A.
1.1.2 Modular construction
The SVS/12 system is based on a modular concept. This
means that any combination and sequence of panels is
possible. Installations are supplied in sections up to 2.52 m
wide and can be constructed of narrow and wide panels.
The sections are mounted, assembled, screwed and tested
as complete units. The modular construction means that
existing systems can also be extended with one or more
panels.
1.1.3 Design
The SVS/12 system complies with all applicable safety,
reliability and environmental regulations.
The following is a summary of the principal design features.
Insulation
The primary components under voltage are epoxy resin
insulated. This prevents faults due to open arcing. All
connections between the primary components are provided
with rubber sleeves. This ensures that the same level of
insulation safety is maintained throughout the system. As a
result, the SVS/12 system belongs to the category of
"compartmented switchgear and controlgear"
(IEC 62271-200).
The earthed metal enclosure guarantees the safety of
personnel during normal operation (IEC 62271-200).
Mechanical interlocks
Thanks to built-in, mechanical interlocks, activities such as
earthing of cables and changing of fuses can only be
carried out in a safe manner. The mechanical interlocks
also prevent unauthorised switching operations.
Connections
The SVS/12 panels can be connected in three ways:
Via cables with plug-in connectors, for connection of 1
or 2 cables per phase.
For this purpose the SVS/12 is equipped with
connection cones (EN 50181).
Via Eaton Magnefix cable boxes. In this case, the
SVS/12 is equipped with locked access doors. These
remain closed until the cable is safely earthed.
Via cable socket connections In this case too, the
SVS/12 is equipped with locked access doors.
Materials
In accordance with current requirements, all materials used
in the SVS/12 system are environment-friendly, not only
while in use but also at the end of their technical service
life.
Transport
An SVS/12 system can be transported in sections up to
2.52 m wide. Each section can be provided with four lifting
eyes or a lifting frame. If no lifting facilities are provided, the
sections can also be transported with a fork lift truck, with
braces and transport wheels or with steel rollers.
Set-up
The panels can be placed on a level floor and fastened to it
with wedge bolts. All assembly work is carried out from the
front of the installation.
1.1.4 Operation
Each panel is equipped with a control panel. This contains
the mimicdiagram and the necessary controls and
indicators. The type of panel is clearly recognisable from
the mimic diagram.
1.1.5 Separate compartment for secondary
equipment
Secondary equipment, such as protection relays and
measuring instruments, can be accommodated in a
separate compartment on top of the panel. The auxiliary
cables are connected to terminal strips at the bottom of the
panel.