Siemens 7SC80 Manual page 431

[dw_FaultProfileSide2withCurrent, 1, en_US]
Figure 2-144
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 Undervoltage protection of side 2 function
does not pick up. Therefore no fault record is created when voltage protection is activated in a healthy system.
It is important to understand, however, that if a low voltage condition exists on the load after the circuit
breaker is closed (unlike
The following figure shows the logic diagram of the undervoltage protection function.
The logic diagram also applies to setting the phase-specific undervoltage protection (Vphph selective or
Vph-n selective). The threshold values and time delays have to be replaced with the phase-specific
values.
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017
Typical Fault Profile for Load-Side Connection of the Voltage Transformers (with Current
Supervision)
Figure 2-144), the desired pickup of the element will be delayed by 60 ms.
2.30 Additional Applications with 6 Voltage Inputs
Functions
431