RECLOSER CONTROL EVRC2A-N6,NT
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HNOLOGY
7.17. Other Element
7.17.1. Sequence Coordination
When several Reclosers are connected in series to protect distribution systems, EVRC2A
contains Sequence Coordination feature which can prevent the simultaneous trip operations in
both of Back-up and Down-line Reclosers due to phase/ground fault. Sequence Coordination
feature is activated only if one out of several Down-line Reclosers connected to one Back-up
Recloser detects a fault current.
The following rules should be kept to activate Sequence Coordination feature.
1)
The same characteristics of fast and delay operations in the total number of the trip
operations and identical basic Time Current Curves should be set for all Reclosers connected
in series.
2)
The identical reclose interval time should be set for all Reclosers in series.
3)
To coordinate the protection characteristics, an additional delay operation time (at least 100
ms) should be applied to the Time Current Curve characteristics of Back-up Recloser, not to
those of Down-line Reclosers.
4)
The reset time of Back-up Recloser should be set longer than any reclose interval time of all
Down-line Reclosers. This setting will prevent the reset operation of Back-up Recloser
during the reclose operation of Down-lines.
The Sequence Coordination feature should be enabled to the following settings.
PRIMARY SETTING / PROTECTION / OTHER ELEMENT / Seq' Coordi'
Range
OFF, ON
Default
OFF
Step
~
Sequence coordination offers the function of preventing unnecessary
operation of the backup recloser when two more reclosers are
connected in series.
If function = OFF,
the feature is not operational.
If function = ON,
the feature is operational.
[ OTHER ELEMENT ]
>Seq’ Coordi’: OFF
L.O Priority: GND
F/I Reset: AUTO
Summary of Contents for EVRC2A-N6-NT
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