Setting Notes - Siemens 7SC80 Manual

Functions
2.6 Voltage Protection 27, 59
[logik_59n-it-funk-14012013, 1, en_US]
Figure 2-53

Setting Notes

2.6.5
General
Voltage protection is only effective and accessible if address 150 27/59 is set to Enabled during configura-
tion of protection functions. If this function is not required, then Disabled is set.
The voltage to be evaluated is selected in Power System Data 1 (see Section
Table 2-11).
Overvoltage protection can be turned ON or OFF, or set to Alarm Only at address 5001 FCT 59.
Undervoltage protection can be turned ON or OFF or set to Alarm Only at address 5101 FCT 27.
If the protection function is switched ON, tripping is initiated, a trip log started, and fault recording is triggered
if the limit has been exceeded and the time delay has elapsed.
When setting Alarm Only, no trip command is given, no trip log is initiated, and no spontaneous fault indi-
cation is issued.
Overvoltage Protection with Phase-to-phase or Phase-to-ground Voltages
The largest of the applied voltages is evaluated for the phase-to-phase or phase-to-ground overvoltage protec-
tion.
The threshold values are set in the value to be evaluated (see Section
Table 2-11).
The overvoltage protection has two elements. The pickup value of the lower threshold (address 5002 or 5003,
59-1 PICKUP, depending on the phase-to-ground or the phase-to-phase voltages, can be assigned a longer
time delay (address 5004, 59-1 DELAY) and the upper threshold element (address 5005 or 5006, 59-2
PICKUP) a shorter (address 5007, 59-2 DELAY) time delay. There are no specific procedures on how the
pickup values are set. However, as the function is mainly used to prevent high insulation damage to system
components and users, the threshold value 5002 , 5003 59-1 PICKUP lies generally between 110 % and 115
% of the nominal voltage and setting value 5005, 5006 59-2 PICKUP at approximately 130 %.
The time delays of the overvoltage elements are entered at addresses 5004 59-1 DELAY and 5007 59-2
DELAY, and should be selected in such manner that they make allowance for brief voltage peaks that are
generated during switching operations and also enable clearance of stationary overvoltages in due time.
The choice between phase-to-ground and phase-to-phase voltage allows voltage asymmetries (e.g. caused by
a ground fault) to be taken into account (phase-to-ground) or to remain unconsidered (phase-to-phase)
during evaluation.
194
Logic Diagram of the Dependent Displacement Voltage Protection
2.6 Voltage Protection 27,
2.6 Voltage Protection 27,
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017
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