7SR210 & 7SR220 Description of Operation
Unrestricted Page 80 of 94
©2018 Siemens Protection Devices Limited
5.4
CT Supervision (60CTS & 60CTS-I)
The relay has two methods of detecting a CT failure, depending on the relay variant.
5.4.1
(60CTS-I) – 7SR21 & 7SR22
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
CTS-I
for more than
60CTS-I Delay
then a CT failure output
(
60CTS-I Operated
) is given. If all three input currents fall below the setting, CT failure is not raised.
Operation of the CT supervision elements can be inhibited from: -
Inhibit 60CTS-I
A binary input, virtual input or remote data Comms.
60CTS-I Delay
IL1
IL2
IL3
60CTS I
<
Any 2 phases
but not all 3
&
Inhibit 60CTS
60CTS-I Element
Enabled
Disabled
60CTS-I Operated
Inhibit 60CTS
60CTS-I Pick-UP
60CTS-I Operated
&
Figure 5.4.1-1
Logic Diagram: CT Supervision Function (60CTS-I) – 7SR21 & 7SR22
5.4.2
(60CTS) – 7SR22
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 input, virtual input or remote data Comms.
&
60CTS Delay
VL1
VL2
VL3
NPS
Filter
V2
60CTS Vnps
<
IL1
IL2
IL3
NPS
Filter
I2
60CTS Inps
>
&
Inhibit 60CTS
60CTS Element
Enabled
Disabled
&
60CTS Operated
Inhibit 60CTS
60CTS Pick-Up
60CTS Operated
Figure 5.4.2-1
Logic Diagram: CT Supervision Function (60CTS) – 7SR22
Summary of Contents for Argus 7SR21
Page 1: ...Energy Management 7SR21 7SR22 Argus Overcurrent Relay Reyrolle Protection Devices ...
Page 2: ......
Page 4: ...Contents 7SR11 and 7SR12 Page 2 of 2 2018 Siemens Protection Devices Limited ...
Page 185: ...7SR210 Settings Guide Unrestricted 2018 Siemens Protection Devices Limited Page 61 of 61 ...
Page 277: ...7SR220 Settings Guide Unrestricted Page 72 of 107 2013 Siemens Protection Devices Limited ...
Page 382: ...7SR220 Technical Manual Chapter 4 Page 2 of 96 2017 Siemens Protection Devices Limited ...
Page 386: ...7SR220 Technical Manual Chapter 4 Page 6 of 96 2017 Siemens Protection Devices Limited ...
Page 398: ...7SR220 Technical Manual Chapter 4 Page 18 of 96 2017 Siemens Protection Devices Limited ...
Page 414: ...7SR220 Technical Manual Chapter 4 Page 34 of 96 2017 Siemens Protection Devices Limited ...
Page 466: ...7SR220 Technical Manual Chapter 4 Page 86 of 96 2017 Siemens Protection Devices Limited ...
Page 468: ...7SR220 Technical Manual Chapter 4 Page 88 of 96 2017 Siemens Protection Devices Limited ...
Page 470: ...7SR220 Technical Manual Chapter 4 Page 90 of 96 2017 Siemens Protection Devices Limited ...
Page 472: ...7SR220 Technical Manual Chapter 4 Page 92 of 96 2017 Siemens Protection Devices Limited ...
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