
Multi-Function Control ETMFC610
http://www.entecene.co.kr
212
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8.2.6. Sensitive Earth Fault (50SG)
The sensitive earth fault (SEF) is applicable to systems that have restricted current flow for phase
to earth fault. The SEF is not applicable to the case in 4 wire multi-earthed systems. The sensitivity
of SEF element for non-earthed systems is dependent upon available fault current and the accuracy
of CTs. For SEF element, ETMFC610 has the separate SEF terminal on side panel. This input can
be connected in series with the provided phase CT’s(standard) or connected to a separate window
type ZCT.
The SEF element provides a definite time delay versus sensitive earth fault current. The SEF
element is enabled in the group setting and PROTECTION ENABLED, GROUND ENABLED and
SEF ENABLED on user interface panel.
For user systems, a directional SEF is available. The directional control is polarized by a zero
sequence voltage(V0). The CVD or PTs should be connected Wye-grounded.
A sensitive earth fault element does not work during the inrush restraint to prevent malfunction of
the inrush current that occurs when the recloser or nearby distribution device is closed.
50SG Pickup Current
CURRENT INPUT
SET
Setting Value
-
+
50SG1
LATCH
RST
FLTS
50SG1T
FI RESET
TIME DELAY
SEF LAMP
ESPROT
SEF
ENABLED
EGPROT
GROUND
ENABLED
BLOCKING by
SEF INRUSH
EPROT
PROTECTION
ENABLED
Figure 8-14. Sensitive Earth Fault (50SG) Logic Diagram
‘INST OC-SEF’ menu is sub-divided as follow;
[INST OC - SEF]
>1.(+)INST OC-SEF
2.(-)INST OC-SEF
Содержание ETMFC610
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