Construction - Siemens 7SJ47 SIPROTEC easy Handbuch

Manual 7SJ46
Overcurrent protection
•
2-stage overcurrent protection. The device has always a
normal stage for phase currents (definite-time or inverse-
time). For the second stage, the user can choose between a
high-current stage for phase currents (definite-time) or a
normal stage for calculated earth currents (definite-time or
inverse-time).
•
Inverse-time overcurrent protection with integrating
measurement method (disk emulation), IEC or ANSI
characteristics.
•
Undelayed tripping possible at any stage when closing onto a
short-circuit.
•
Insensitivity against DC components, inrush and charging
currents as well as higher-frequency transients.
Command output
•
In case there is a fault, tripping will be carried out for at least
500 ms. When a switching operation is carried out the trip
command remains in a waiting state until the circuit-breaker
trips.
Monitoring functions
•
Increased reliability thanks to monitoring of the hardware and
software. The monitoring function controls the live status
contact and the RUN/ERROR LED.
C53000-K1174-C002-4
2.6

Construction

The 7SJ46 overcurrent protection is a compact unit that
comprises all components for:
•
Measuring and processing
•
Alarm and command output
•
Operation and indication
•
Wide range AC/DC power supply
Housing
The device is available for
•
Panel flush mounting and
•
Standard rail mounting
The housings of the 7SJ46 devices are dimensioned to fit into
standard panel cutouts.
In the condensation proof version, the module inside the device
is sealed with protective lacquer so that the device can be used
even in very rough and extremely humid environmental
conditions.
Construction
45