Figure. 5.6.1 - 200. Primary side high-impedance earth fault.
In this example there is a high-impedance earth fault. It does not activate the function, if the
measurement conditions are met, while the calculated and measured residual current difference does
not reach the limit. The
I
sum
difference setting should be set according to the application in order to
reach maximum security and maximum sensitivity for the network earthing.
Events and registers
The current transformer supervision function (abbreviated "CTS" in event block names) generates
events and registers from the status changes in ALARM ACTIVATED and BLOCKED signals. The user
can select which event messages are stored in the main event buffer: ON, OFF, or both. The function
offers two (2) independent stages.
The events triggered by the function are recorded with a time stamp and with process data values.
Table. 5.6.1 - 284. Event messages.
Event block name
Event names
CTS1
Alarm ON
CTS1
Alarm OFF
CTS1
Block ON
CTS1
Block OFF
CTS2
Alarm ON
CTS2
Alarm OFF
CTS2
Block ON
CTS2
Block OFF
The function registers its operation into the last twelve (12) time-stamped registers; this information is
available for all provided instances separately. The register of the function records the ON event
process data for ACTIVATED, BLOCKED, etc. The table below presents the structure of the function's
register content.
A
AQ
Q-M257
-M257
Instruction manual
Version: 2.07
© Arcteq Relays Ltd
IM00021
375
Summary of Contents for AQ-M257
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