Toshiba GR200 Series Instruction Manual page 1328

Current transformer failure detected with DIF (DIF-CT)
10.5.2
The CT failure can be monitored by the operation of DIFL-CTF element† in the current
differential function (DIF); the automatic supervision function can alarm its erroneous
operation by the notification from the DIF function.
†Note: The DIF function has the supervision feature itself; hence, the user can program
the criteria for the supervision using setting [DIFL-CTF]; then set On for the
scheme switch [CTFL-EN]. For more information about the DIF supervision, see
Chapter
current monitor
Error level
(i)
Generally, the default error level is set at level 3 (Minor error), but the user can program the
level using setting [CHK_DIF_CTF:LVl]; then, set On for the setting [CHK_DIF_CTF:Sw]. The
manufacturer sets the time for the detection for 10 seconds. The function resets instantly after
the error is cleared.
Error message
(ii)
When the function operates and detects error, an error message can be shown at the LED and
the LCD screen.
Table 10.5-5 Error messages provided by the supervisor in CHK_DIF_CTF
Message and level
DIF-CT fail
Error level
Table 10.5-6 Detailed information in Hexadecimal in CHK_DIF_CTF
Display area
N/A
Relay application: Current differential protection for the line: Differential
.
Meaning of the information
Failure detection on the CT
Minor error (Level 3)
Meaning of the detailed information
(No information is displayed)
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6F2S1914 (0.49)
GRL200 (Soft 033 & 037)