Siemens SIPROTEC 7SJ80 User Manual

[stoerfallverlauf-mit-stromkriterium-260602-kn, 1, en_US]
Figure 2-46
Typical fault profile for load side connection of the voltage transformers (with current supervi-
sion)
Upon the closing of the circuit breaker, current criterion is delayed for a short period of time. If the voltage
criterion drops out during this time period (about 60 ms), the protection function does not pick up. Therefore
no fault record is created when voltage protection is activated in a healthy system. It is important to under-
stand, however, that if a low voltage condition exists on the load after the circuit breaker is closed (unlike
Figure 2-46), the desired pickup of the element will be delayed by 60 ms.
The following figure shows the logic diagram of the undervoltage protection function.
Functions
2.6 Voltage Protection 27, 59
126 SIPROTEC 4, 7SJ80, Manual
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