8
2.2 Reference Standards
The DS1 series apparatus complies with the following
Standards: IEC 62271-103 Special Purpose Capacitor Switch
with no making and breaking capability. IEC62271-100 has
been applied for capacitive switching (with some exclusions),
since is more demanding.
2.3 Fixed capacitor-switch
The fixed capacitor-switch (see fig. 4) corresponds to the basic
version complete with a front protection shield and frame.
The anchoring holes are drilled in the lower part of the frame.
The terminal board connection, fixed on the upper protection, is
available for connecting the auxiliary circuits of the apparatus.
The earthing screw is located on the side of the apparatus.
For further details, consult the “External Drawing for DS1
Integration” at the end of this document.
2.4 Main electrical characteristics
The main electrical ratings of DS1 are:
Rated Voltage
17.5 kV at 50 Hz
15 kV at 60 Hz
Rated current
630 A at 50 Hz
600 A at 60 Hz
Short Time Current
20 kA for 0.5 s
Figure 5. Typical circuit for integration with MECB
An additional safety interlock should be used
in order to prevent DS1 from operating in the
maintenance mode (due to incorrect wiring
of the upstream CB interlock).
See specific section for details of the
upstream interlock feature.
ABB declines all liability for the product
following failure to comply with these
guidelines when DS1 is installed.
Since it is a special purpose capacitor switch based on diodes
for switching,
DS1 is unable to break and make a fault
current
. It can switch up to its rated current, indicated above.
However, it has a short time withstand current of 20 kA for 0.5
s that allows the upstream protection to operate and interrupt
the fault, thus preventing the DS1 and capacitors from being
damaged.
A supply side protection must always be present (circuit
breaker), and it is preferable for fast fuses to be installed as
well.
Additional interlocks are strongly recommended in order to
prevent DS1 from operating in the following conditions:
− During a fault (when an upstream protection is tripping)
− When a downstream earth switch has not been opened (e.g.
after maintenance).
DS1 has a generic interlock (Pin 10 internally performs loop
with Pin 20 of terminal block) with the scope of implementing
this interlocking function. See specific section.
Coordination signals and interlocks (mandatory) are described
in the following section.
Provided
by
Northeast
Power
Systems,
Inc.
(NEPSI)
