Trip/Close Circuit Supervision (74T/Ccs); Trip Circuit Supervision Connections - Siemens 7SR10 Argus Series Manual

5.4

Trip/Close Circuit Supervision (74T/CCS)

The relay provides three trips and three close circuit supervision elements, all elements are identical in operation
and independent from each other allowing 3 trip and 3 close circuits to be monitored.
One or more binary inputs can be mapped to 74TCS-n. The inputs are connected into the trip circuit such that at
least one input is energised when the trip circuit wiring is intact. If all the mapped inputs become de-energised,
due to a break in the trip circuit wiring or loss of supply an output is given.
The 74TCS-n Delay setting prevents the failure being incorrectly indicated during circuit breaker operation. This
delay should be greater than the operating time of the circuit breaker.
The use of one or two binary inputs mapped to the same Trip Circuit Supervision element (e.g. 74TCS-n) allows
the user to realise several alternative monitoring schemes.
74TCS-n
Enabled
Disabled
74TCS-n
74TCS-n
Figure 5-4
74CCS-n
Enabled
Disabled
74CCS-n
74CCS-n
Figure 5-5
5.4.1

Trip Circuit Supervision Connections

The following circuits are derived from UK ENA S15 standard schemes H5, H6 and H7.
For compliance with this standard:
Where more than one device is used to trip the CB then connections should be looped between the
tripping contacts. To ensure that all wiring is monitored the binary input must be at the end of the looped
wiring.
Resistors must be continuously rated and where possible should be of wire-wound construction.
© 2018 Siemens Protection Devices Limited
&
≥1
NOTE: Diagram shows two binary inputs mapped
to the same Trip Circuit Supervision element
Logic Diagram: Trip Circuit Supervision Feature (74TCS)
&
≥1
NOTE: Diagram shows two binary inputs mapped
to the same Close Circuit Supervision element
Logic Diagram: Close Circuit Supervision Feature (74CCS)
7SR10, 7SR11, 7SR12 Applications Guide
74TCS-n Delay
74CCS-n Delay
Chapter 7 Page 37 of 41
TCS-n
CCS-n