Ct Failure Detector - GE UR Series Instruction Manual

5 SETTINGS
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PATH: SETTINGS CONTROL ELEMENTS
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CT FAILURE
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DETECTOR
MESSAGE
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The CT FAIL logic is designed to detect problems with the system current transformers used to supply current to the relay.
This logic detects the presence of a zero sequence current at the supervised source of current without a simultaneous zero
sequence current at another source, zero sequence voltage or some protection element condition.
CT FAIL logic (see figure below) is based on the presence of the zero sequence current in the supervised CT source and
absence of one of three or all three conditions as follows:
• zero sequence current at different source current (may be different set of CTs or different CT core of the same CT)
• zero sequence voltage at the assigned source
• appropriate protection element or remote signal
CT FAIL FUNCTION:
This setting is used to Enable/Disable operation of the element.
CT FAIL BLOCK:
This setting is used to select a FlexLogic™ operand that blocks operation of the element during some conditions (i.e. open
pole in process of the single pole tripping-reclosing) when CT Fail should be blocked. Remote signals representing opera-
tion of some remote current protection elements via communication channel or local ones can be chosen as well.
CT FAIL 3I0 INPUT 1:
This setting is used to select the source for the current for input 1. Most important protection element of the relay should be
assigned to the same source.
CT FAIL 3I0 INPUT 1 PICKUP:
This setting is used to select the pickup value for 3I_0 for the input 1 (main supervised CT source) of the relay.
GE Power Management
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MONITORING ELEMENTS
CT FAIL FUNCTION:
Disabled
CT FAIL BLOCK:
Off
CT FAIL 3I0 INPUT 1:
SRC 1
CT FAIL 3I0 INPUT 1
PKP: 0.2 pu
CT FAIL 3I0 INPUT 2:
SRC 2
CT FAIL 3I0 INPUT 2
PKP: 0.2 pu
CT FAIL 3V0 INPUT:
SRC 1
CT FAIL 3V0 INPUT
PKP: 0.2 pu
CT FAIL PICKUP
DELAY: 1.000 s
CT FAIL TARGET:
Self-reset
CT FAIL EVENTS:
Disabled
L90 Line Differential Relay
5.6 CONTROL ELEMENTS

5.6.10 CT FAILURE DETECTOR

CT FAILURE DETECTOR
Range: Disabled, Enabled
Range: FlexLogic™ operand
Range: SRC 1, SRC 2,..., SRC 6
Range: 0.0 to 2.0 pu in steps of 0.1
Range: SRC 1, SRC 2,..., SRC 6
Range: 0.0 to 2.0 pu in steps of 0.1
Range: SRC 1, SRC 2,..., SRC 6
Range: 0.0 to 2.0 pu in steps of 0.1
Range: 0.000 to 65.535 s in steps of 0.001
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
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