Functions
2.15 Monitoring Functions
SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011
205
Figure 2-87 Broken-wire monitoring
Voltage Phase Sequence
The phase rotation of the measured voltages is checked by monitoring of the voltage phase sequence.
U
L1
before U
L2
before U
L3
This check takes place if each measured voltage has a minimum magnitude of
|U
L1
|, |U
L2
|, |U
L3
| > 40 V/√3
In case of negative phase rotation, the indication „Fail Ph. Seq.“ (No. 171) is issued.