Broken Wire Monitoring Of Voltage Transformer Circuits - Siemens SIPROTEC 7SJ62 Manual

Multi-functional protective relay with local control

Hide thumbs Also See for SIPROTEC 7SJ62:

Table of Contents

2.11.1.7 Broken Wire Monitoring of Voltage Transformer Circuits

Requirements

This function is only available in device version „World" (Ordering Information Pos. 10 = B), as it is only used

in certain regions. Furthermore, the measurement of all three phase-to-ground voltages is a requirement. If only

two phase-to-phase voltages were measured, it would not be possible to evaluate two of the required criteria.

The broken wire monitoring function monitors the voltage transformer circuits of the secondary system with

regard to failure. One distinguishes between single-pole, two-pole and three-pole failures.

Mode of Operation / Logic

All three phase-to-ground voltages, the displacement voltage and the three phase currents are measured. The

required values are calculated for the respective criteria and eventually a decision is made. The resulting alarm

message may be delayed. A blocking of the protection functions is however not effected. This is done by the

measuring voltage failure detection.

The broken wire monitoring is also active during a fault. The function may be enabled or disabled.

SIPROTEC, 7SJ62/64, Manual

C53000-G1140-C207-2, Release date 01.2008

2.11 Monitoring Functions