Figure. 5.4.10. - 66. Restricted earth fault on outside of Y winding transformer.
If the fault is located inside of the transformer and thus inside of the protection area the REF function
catches the fault with high sensitivity since the measured residual current directions are now opposite
for the outside fault situation the measured differential current is high.
Figure. 5.4.10. - 67. Restricted earth fault on inside of Y winding transformer.
Events and registers
The REF function generates events and registers from the status changes of the Trip activated and
blocked signals. To main event buffer it is possible to select status “On” or “Off” messages.
12 last registers are available in the function where the triggering event of the function (Trip activated or
blocked) is recorded with time stamp and process data values.
AQ-F255
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
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