ABB REF615 L - Identification; Function Block; Functionality

4.2 Earth-fault protection
4.2.1 Non-directional earth-fault protection EFxPTOC
4.2.1.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Non-directional earth-fault protection -
Low stage
EFLPTOC Io> 51N-1
Non-directional earth-fault protection -
High stage
EFHPTOC Io>> 51N-2
Non-directional earth-fault protection -
Instantaneous stage
EFIPTOC Io>>> 50N/51N
4.2.1.2 Function block
EFLPTOC
Io
BLOCK
START
OPERATE
ENA_MULT
EFHPTOC
Io
BLOCK
START
OPERATE
ENA_MULT
EFIPTOC
Io
BLOCK
START
OPERATE
ENA_MULT
A070432 V2 EN
Figure 131: Function block
4.2.1.3 Functionality
The earth-fault function EFxPTOC is used as non-directional earth-fault protection
for feeders.
The function starts and operates when the residual current exceeds the set limit.
The operate time characteristic for low stage EFLPTOC and high stage EFHPTOC
can be selected to be either definite time (DT) or inverse definite minimum time
(IDMT). The instantaneous stage EFIPTOC always operates with the DT
characteristic.
In the DT mode, the function operates after a predefined operate time and resets
when the fault current disappears. The IDMT mode provides current-dependent
timer characteristics.
The function contains a blocking functionality. It is possible to block function
outputs, timers or the function itself, if desired.
1YHT530004D05 D Section 4
Protection functions
615 series 263
Technical Manual