Application Scope - Siemens siprotec SJ62 User Manual

1 Introduction
1.2

Application Scope

Protective Func-
tions
Control Functions
25
The numerical, multi-functional SIPROTEC 4 7SJ62/63/64 are versatile devices de-
signed for protection, control and monitoring of busbar feeders. The devices can be
used for line protection in networks that are grounded, low-resistance grounded, un-
grounded, or of a compensated neutral point structure. They are suited for networks
that are radial or looped, and for lines with single or multi-terminal feeds. The devices
are equipped with motor protection applicable for asynchronous machines of all sizes.
The devices include the functions that are necessary for protection, monitoring of
circuit breaker positions, and control of the circuit breakers in straight bus applications
or breaker-and-a-half configurations; therefore, the devices can be universally em-
ployed. The devices provide excellent backup facilities of differential protective
schemes of lines, transformers, generators, motors, and busbars of all voltage levels.
Non-directional overcurrent protection (50, 50N, 51, 51N) is the basis of the device.
There are two definite time overcurrent protective elements and one inverse time over-
current protective element for phase and ground current. For inverse time overcurrent
protective elements, several characteristics of different standards are provided. Alter-
natively, user-defined characteristics can be programmed.
Depending on the version of the device that is ordered, the non-directional overcurrent
protection can be supplemented with directional overcurrent protection (67, 67N),
breaker failure protection (50BF), and sensitive ground fault detection for high-resis-
tance ground faults. The highly sensitive ground fault detection can be directional or
non-directional.
In addition to the fault protection functions already mentioned, other protective func-
tions are available. Some of them depend on the version of the device that is ordered.
These additional functions include frequency protection (81O/U), overvoltage protec-
tion (59) and undervoltage protection (27), negative sequence protection (46) and
overload protection (49) with start inhibit for motors (66/68) and motor starting protec-
tion (48), as well as automatic reclosing (79) which allows different reclosing cycles on
overhead lines. The automatic reclosing system may also be connected externally. To
ensure quick detection of the fault, the device is equipped with a fault locator.
A protection feature can be ordered for the detection of intermittent ground faults
which detects and accumulates transient ground faults.
External detectors account for ambient temperatures or coolant temperatures (by
means of an external RTD-box).
Before reclosing after three-pole tripping 7SJ64 can verify the validity of the reclosure
by voltage check and/or synchronous check. The synchronization function can also be
controlled externally.
The device provides a control function which can be accomplished for activating and
deactivating switchgears via the integrated operator panel, the system interface,
binary inputs, and the serial port using a personal computer with DIGSI.
The status of the primary equipment can be transmitted to the device via auxiliary con-
tacts connected to binary inputs. The present status (or position) of the primary equip-
ment can be displayed on the device, and used for interlocking or plausibility monitor-
ing. The number of the operating equipment to be switched is limited by the binary
inputs and outputs available in the device or the binary inputs and outputs allocated
for the switch position indications. Depending on the primary equipment being con-
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015