Setting Notes - Siemens 7SK80 Manual

Figure 2-59 Message logic for trip circuit supervision

2.10.2.2 Setting Notes

General
The function is only effective and accessible if address 182 (Section 2.1.1.2) was set to either 2 Binary
Inputs or 1 Binary Input during configuration, the appropriate number of binary inputs has been config-
ured accordingly for this purpose and the function FCT 74TC is ON at address 8201. If the allocation of the
required binary inputs does not match the selected supervision type, a message to this effect is generated
(„74TC ProgFail"). If the trip circuit monitor is not to be used at all, then Disabled is set at address 182.
In order to ensure that the longest possible duration of a trip command can be reliably bridged, and an indica-
tion is generated in case of an actual fault in the trip circuit, the indication regarding a trip circuit interruption is
delayed. The time delay is set under address 8202 Alarm Delay.
Supervision with One Binary Input
Note: When using only one binary input (BI) for the trip circuit monitor, malfunctions, such as interruption of the
trip circuit or loss of battery voltage are detected in general, but trip circuit failures while a trip command is active
cannot be detected. Therefore, the measurement must take place over a period of time that bridges the longest
possible duration of a closed trip contact. This is ensured by the fixed number of measurement repetitions and
the time between the state checks.
When using only one binary input, a resistor R is inserted into the circuit on the system side, instead of the
missing second binary input. Through appropriate sizing of the resistor and depending on the system condi-
tions, a lower control voltage is mostly sufficient.
Information for dimensioning resistor R is given in the Chapter "Installation and Commissioning" under Config-
uration Notes in the Section "Trip Circuit Supervision".
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
Functions
2.10 Monitoring Functions
181