Application - ABB Relion SMU615 Technical Manual

Section 5
Supervision functions
5.1.5
124
A070785 V2 EN
Figure 84: Functional module diagram
TCS status
This module receives the trip circuit status from the hardware. A detected failure in the
trip circuit activates the timer.
Timer
Once activated, the timer runs until the set value of Operate delay time has elapsed.
The time characteristic is according to DT. When the operation timer has reached the
maximum time value, the ALARM output is activated. If a drop-off situation occurs
during the operate time up counting, the fixed 0.5 s reset timer is activated. After that
time, the operation timer is reset.
The BLOCK input can be controlled with a binary input, a horizontal communication
input or an internal signal of the merging unit's program. The activation of the BLOCK
input prevents the ALARM output to be activated.

Application

TCSSCBR detects faults in the electrical control circuit of the circuit breaker. The
function can supervise both open and closed coil circuits. This supervision is
necessary to find out the vitality of the control circuits continuously.
Figure 85 shows an application of the trip circuit supervision function use. The best
solution is to connect an external R
internal contact. Although the circuit breaker internal contact is open, TCS can see the
trip circuit through R . The R
ext
through the resistance remains small, that is, it does not harm or overload the circuit
breaker's trip coil.
shunt resistor in parallel with the circuit breaker
ext
resistor should have such a resistance that the current
ext
1MRS758407 B
SMU615
Technical Manual