Siemens 6MD86 - Undervoltage Protection with 3-Phase Voltage; Overview of Functions; Structure of the Function

Undervoltage Protection with 3-Phase Voltage
Overview of Functions
The function Undervoltage protection with 3-phase voltage (ANSI 27):
•
Monitors the permissible voltage range
•
Protects equipment (for example, plant components and machines) against damages caused by under-
voltage
•
Handles disconnection or load shedding tasks in a system
Structure of the Function
The function Undervoltage protection with 3-phase voltage is used in protection function groups with
voltage measurement.
The function Undervoltage protection with 3-phase voltage comes factory-set with 2 Definite-time under-
voltage protection stages.
In the function Undervoltage protection with 3-phase voltage, the following stages can be operated simul-
taneously:
•
3 stages Definite-time undervoltage protection
•
2 stages Inverse-time undervoltage protection
Stages that are not preconfigured are shown in gray in the following figure.
The protection function is structured such that one current-flow criterion can act on all undervoltage protec-
tion stages (see Figure 7-148). If the protection function group used has no current measurement, you can
only set the current-flow criterion as fulfilled via the corresponding binary input signal.
[dwstru3p-110211-01.tif, 4, en_US]
Figure 7-148 Structure/Embedding of the Function
7.16
7.16.1
7.16.2
Protection and Automation Functions
7.16 Undervoltage Protection with 3-Phase Voltage
SIPROTEC 5, High-Voltage Bay Controller, Manual 805
C53000-G5040-C015-9, Edition 11.2017