Application - ABB RELION 620 Series Technical Manual

1MRS757644 F
4.2.1.7
620 series
Technical Manual
Operating curve type
(14) IEC Long Time Inverse
(15) IEC Definite Time
(17) User programmable curve
(18) RI type
(19) RD type
EFIPTOC supports only definite time characteristics.
For a detailed description of timers, see the
features
Table 376: Reset time characteristics supported by different stages
Reset curve type EFLPTOC
(1) Immediate
(2) Def time reset
(3) Inverse reset
The Type of reset curve setting does not apply to EFIPTOC or when
the DT operation is selected. The reset is purely defined by the Reset
delay time setting.

Application

EFxPTOC is designed for protection and clearance of earth faults in distribution and
sub-transmission networks where the neutral point is isolated or earthed via a
resonance coil or through low resistance. It also applies to solidly earthed networks
and earth-fault protection of different equipment connected to the power systems,
such as shunt capacitor bank or shunt reactors and for backup earth-fault protection of
power transformers.
Many applications require several steps using different current start levels and time
delays. EFxPTOC consists of three different protection stages.
• Low EFLPTOC
• High EFHPTOC
• Instantaneous EFIPTOC
section in this manual.
EFHPTOC
x x
x x
x x
Section 4
Protection functions
EFLPTOC EFHPTOC
x
x
x
x
x
General function block
Note
Available for all operate time curves
Available for all operate time curves
Available only for ANSI and user
programmable curves
x
x
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