Siemens SIPROTEC 7SJ80 User Manual

[7sjx_logic_51-phase, 1, en_US]
Figure 2-14
Logic diagram of the voltage-restraint inverse-time overcurrent protection
Dynamic Cold Load Pickup Function
It may be necessary to dynamically increase the pickup thresholds of the overcurrent protection if certain
system components exhibit an increased power consumption when they are switched on after a long period
of zero voltage (e.g. air-conditioning systems, heating installations, motors). Thus, a general increase of
pickup thresholds can be avoided taking into consideration such starting conditions.
This dynamic pickup value changeover fuction is common to all overcurrent elements and is described in
Section 2.4 Dynamic Cold Load Pickup. The alternative pickup values can be set individually for each element
of the time overcurrent protection.
2.2.6
Functions
2.2 Overcurrent Protection 50, 51, 50N, 51N
SIPROTEC 4, 7SJ80, Manual 67
E50417-G1140-C343-A8, Edition 12.2017

Siemens SIPROTEC 7SJ80 Specifications

General

Rated Frequency	50/60 Hz
Rated Current	1 A / 5 A
Operating Temperature	-25°C to +55°C
Storage Temperature	-40°C to +70°C
Current Transformer Inputs	4
Application	Protection of feeders, motors, transformers, and generators
Rated Voltage	100-240 V AC/DC
Communication Protocols	IEC 61850, Modbus, DNP3, IEC 60870-5-103
Display	Graphical LCD
Mounting	Flush mounting
Protection Functions	Overcurrent, Earth fault
Communication Interfaces	Ethernet, RS485
Housing	Plastic
Weight	Approx. 1.5 kg