Description - Siemens siprotec SJ62 User Manual

2.11.2.1 Description

Supervision with
Two Binary Inputs
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
When using two binary inputs, these are connected according to Figure 2-62, parallel
to the associated trip contact on one side, and parallel to the circuit breaker auxiliary
contacts on the other.
Figure 2-62 Principle of the trip circuit monitoring with two binary inputs
Supervision with two binary inputs not only detects interruptions in the trip circuit and
loss of control voltage, it also supervises the response of the circuit breaker using the
position of the circuit breaker auxiliary contacts.
Depending on the conditions of the trip contact and the circuit breaker, the binary
inputs are activated (logical condition "H" in Table 2-10), or not activated (logical con-
dition "L").
In healthy trip circuits the condition that both binary inputs are not actuated ("L") is only
possible during a short transition period (trip contact is closed, but the circuit breaker
has not yet opened.) A continuous state of this condition is only possible when the trip
circuit has been interrupted, a short-circuit exists in the trip circuit, a loss of battery
voltage occurs, or malfunctions occur with the circuit breaker mechanism. Therefore,
it is used as monitoring criterion.
Table 2-10 Condition table for binary inputs, depending on RTC and CB position
No. Trip contact
1 Open
2 Open
3 Closed
4 Closed
Circuit 52a Contact
breaker
Closed Closed
Open Open
Closed Closed
Open Open
2.11 Monitoring Functions
52b Contact BI 1
Open H
Closed H
Open L
Closed L
BI 2
L
H
L
H
194