Siemens SIPROTEC 4 7SD80 Manual page 113

Monitor", also see Section
formers is indicated (internal blocking) via the binary input
[lo-unterspg-ph-20101108, 1, en_US]
Figure 2-50
Undervoltage Phase-to-Phase
Basically, the phase-to-phase undervoltage protection operates like the phase-to-ground protection except
that it detects phase-to-phase voltages. Accordingly, both phases are indicated during pickup of an under-
voltage element if one of the stage thresholds 27-1-Vpp PICKUP (address 3762) or 27-2-Vpp PICKUP
(address 3764) was undershot. Apart from that,
SIPROTEC 4, 7SD80, Manual
E50417-G1100-C474-A2, Edition 02.2018
2.14.1 Measurement
Logic diagram of the undervoltage protection for phase voltages
2.8 Undervoltage and Overvoltage Protection (optional) 27/59
Supervision) or if the trip of the mcb of the voltage trans-
>FAIL:Feeder VT .
Figure 2-50 also applies generally.
Functions
113