Technical data

32
1MRS751108-MUM
Protection Relay
Technical Reference Manual, General
REX 521
The following values are recommended for the external resistor R
ext
:
A051906
Fig. 5.1.10.-1 Operating principle of the trip-circuit supervision, without an
external resistor. The TCS blocking switch is set, blocking the TCS1
when the circuit breaker is open.
A051907
Fig. 5.1.10.-2 Operating principle of the trip-circuit supervision, with an external
resistor. The TCS blocking switch is open, enabling trip-circuit
supervision independent of circuit breaker position.
If there are more auxiliary contacts available, an opening contact can be series
connected with the R
ext
-resistor. The shunt-resistor circuit is opened when the CB is
closed. Therefore the supervision of the auxiliary contact is also possible.
Table 5.1.10-1 Values recommended for R
ext
Operating voltage U
c
Shunt resistor R
ext
48 V DC
1.2 kΩ, 5 W
60 V DC
5.6 kΩ, 5 W
110 V DC
22 kΩ, 5 W
220 V DC
33 kΩ
, 5 W
+
-
Rs
TCS1
BS
TCSSTATE
ALARM
HW
SW
TCS
R
int
1
2
3
4
X4.2
CBPOS_open
TCS blocking
+
-
Rs
TCS1
BS
TCSSTATE
ALARM
HW
SW
TCS
R
int
1
2
3
4
X4.2
R
ext
CBPOS_open
TCS blocking