Entec EVRC2A-N6-NT, User Manual

Page: 190 / 306

RECLOSER CONTROL EVRC2A-N6,NT http://www.entecene.co.kr
180
EN
HANCED
TEC
HNOLOGY
7.18. Time Overcurrent Curves
The EVRC2A is equipped Standard ANSI/IEEE curves, IEC curves, ESB curves, user-defined
curves and all 37 non standard recloser curves are available.
A Configuration setting determines whether elements set to use ANSI/IEEE curves, IEC curves,
ESB curves, user-defined curves reset instantaneously, or corresponding with electromechanical.
The operation times and reset times refer to ANSI/IEEE C37.112 and IEC 255-3.
The operation times and reset times are defined as follows :
ANSI/IEEE
Trip Time(Sec) = TD
×
( (
α
/ (M
β
-
1)
+ γ
) + TA)
IEC
Trip Time(Sec) = TD
×
( (
α
/ (M
β
-
1)) + TA)
ESB
Trip Time(Sec) = TD
×
( (
α
/ (M
β
-
1)
+ γ
) + TA)
USER-DEFINED
Trip Time(Sec) = TD
×
( (
α
/ (M
β
-
1)
+ γ
) + TA)
Reset Time(Sec) = TD
×
(Rt / (1
-
M
2
))
Table 7-2. Curve Factor
TD
Time dial
TA Time adder
α , β , γ Characteristic constant
M Multiples of pickup current
Rt
Reset characteristic constant
NOTE )
1) “Time Dial” and “Time Adder” settings of each Time Overcurrent(Fast/Delay) menu are
applied to Time dial(TD) and Time adder(TA) respectively.
2)
“Recloser clearing time curves”
are used when rated voltage of recloser is 15
㎸
or 27
㎸
,
otherwise which added 30
㎳
(
±
4
㎳
) are used when it is 38
㎸
.