Ct Supervision (60Cts); 60Cts - 7Sr1702/3; Figure 4-5 Logic Diagram: Ct Supervision Function - Current Inputs Only - Siemens 7SR17 Rho Manual

4.5 CT S
UPERVISION
The relay has two methods of detecting a CT failure, depending on the relay model.
4.5.1

60CTS - 7SR1702/3

The current from each of the Phase Current Transformers is monitored. If one or two of the three input currents
falls below the CT supervision current setting Gn 60CTS-I for more than Gn 60CTS-I Delay then a CT failure
output 60CTS-I is given. If all three input currents fall below the setting, CT failure is not raised.
Outputs are also available to indicate the faulted phase, 60CTS-I PhA , 60CTS-I PhB, and 60CTS-I PhC
Operation of the CT supervision elements can be inhibited from:
Inhibit 60CTS
Figure 4-5
©2014 Siemens Protection Devices Limited
(60CTS)
A binary or virtual input.
Logic Diagram: CT Supervision Function – Current Inputs Only
Chapter 1) 7SR17 Rho Description Of Operation
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