Characteristics - Siemens SIPROTEC 7SJ62 Manual

Introduction

1.3 Characteristics

1.3 Characteristics
General Characteristics
• Powerful 32-bit microprocessor system.
• Complete digital processing and control of measured values, from the sampling of the analog input quanti-
ties to the initiation of outputs, for example, tripping or closing circuit breakers or other switchgear devices.
• Total electrical separation between the internal processing stages of the device and the external transformer,
control, and DC supply circuits of the system because of the design of the binary inputs, outputs, and the
DC or AC converters.
• Complete set of functions necessary for the proper protection of lines, feeders, motors, and busbars.
• Easy device operation through an integrated operator panel or by means of a connected personal computer
running DIGSI.
• Continuous calculation and display of measured and metered values on the front of the device.
• Storage of min/max measured values (slave pointer function) and storage of long-term mean values.
• Recording of event and fault data for the last 8 system faults (fault in a network) with real-time information
as well as instantaneous values for fault recording for a maximum time range of 20 s.
• Constant monitoring of the measured quantities, as well as continuous self-diagnostics covering the hard-
ware and software.
• Communication with SCADA or substation controller equipment via serial interfaces through the choice of
data cable, modem, or optical fibers.
• Battery-buffered clock that can be synchronized with an IRIG-B (via satellite) or DCF77 signal, binary input
signal, or system interface command.
• Motor Statistics: Recording of important statistical motor data (operation and startup information).
• Switching statistics: Recording of the number of trip signals instigated by the device and logging of currents
switched off last by the device, as well as accumulated short circuit currents of each pole of the circuit break-
er.
• Operating Hours Counter: Tracking of operating hours of the equipment being protected.
• Commissioning aids such as connection check, direction determination, status indication of all binary inputs
and outputs, easy check of system interface and influencing of information of the system interface during
test operation
Time Overcurrent Protection 50, 51, 50N, 51N
• Three definite time overcurrent protective elements and one inverse time overcurrent protective element for
phase current and ground current I
• two-phase operation of the time overcurrent protection (I
• Different curves of common standards are available for 51 and 51N, or a user-defined characteristic;
• Blocking capability e.g. for reverse interlocking with any element;
• Instantaneous tripping by any overcurrent element upon switch onto fault is possible;
• In-rush restraint with second harmonic oscillation.
26
or summation current 3I ;
N 0
, I ) is possible;
A C
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008