7SR18 Description Of Operation
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5.3.2 60CTS
Normally the presence of negative phase sequence (NPS) current in a power system is accompanied by NPS
voltage. The presence of NPS current without NPS voltage is used to indicate a current transformer failure.
The element has a setting for NPS current level 60CTS Inps and a setting for NPS voltage level 60CTS Vnps If
the negative sequence current exceeds its setting while the negative sequence voltage is below its setting for
more than 60CTS Delay then a CT failure output (60CTS Operated) is given.
Operation of the CT supervision elements can be inhibited from:
Inhibit 60CTS A binary or virtual input.
Figure 5.3.2-1 Logic Diagram: CT Supervision Function (60CTS)
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