ABB RELION RET670, Applications Manual

Page: 537 / 1016

40 100 40 40 220 t ms ms ms ms ms
D ³ + + + =
EQUATION1266 V1 EN-US
(Equation 426)
where it is considered that:
the operate time of overcurrent protection B1 is 40 ms
the breaker open time
is 100 ms
the resetting time of protection A1 is 40 ms and
the additional margin is 40 ms
9.3 Instantaneous residual overcurrent protection EFPIOC
(50N)
IP14508-1 v3
9.3.1 Identification
M14887-1 v4
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Instantaneous residual overcurrent
protection
EFPIOC
IN>>
IEF V1 EN-US
50N
9.3.2 Application
M12699-3 v5
In many applications, when fault current is limited to a defined value by the object
impedance, an instantaneous ground-fault protection can provide fast and selective
tripping.
The Instantaneous residual overcurrent EFPIOC (50N), which can operate in 15 ms (50
Hz nominal system frequency) for faults characterized by very high currents, is
included in the IED.
9.3.3 Setting guidelines
IP14985-1 v1
M12762-44 v2 M12762-4 v4
The parameters for the Instantaneous residual overcurrent protection EFPIOC (50N)
are set via the local HMI or PCM600.
Some guidelines for the choice of setting parameter for EFPIOC (50N) is given.
1MRK 504 163-UUS A
Section 9
Current protection
Transformer protection RET670 2.2 ANSI 531
Application manual