Four Step Residual Overcurrent Protection, (Zero Sequence Or Negative Sequence Directionality) Ef4Ptoc (51N/67N); Identification; Setting Guidelines - ABB REB670 Applications Manual

1MRK 505 337-UUS -
7.3
7.3.1
7.3.2
Application manual
are uncertainties in the values of protection operation time, breaker opening time and
protection resetting time. Therefor a safety margin has to be included. With normal values
the needed time difference can be calculated according to equation 38.
D ³ + +
t 40 ms 100 ms
EQUATION1266 V1 EN
where it is considered that:
the operation time of overcurrent protection B1 is 40 ms
the breaker open time
the resetting time of protection A1
the additional margin
Four step residual overcurrent protection, (Zero
sequence or negative sequence directionality)
EF4PTOC (51N/67N)

Identification

Function description
Four step residual overcurrent
protection

Setting guidelines

When inverse time overcurrent characteristic is selected, the operate time
of the stage will be the sum of the inverse time delay and the set definite
time delay. Thus, if only the inverse time delay is required, it is important
to set the definite time delay for that stage to zero.
The parameters for the four step residual overcurrent protection, zero or negative
sequence direction EF4PTOC (51N/67N) are set via the local HMI or PCM600.
The following settings can be done for the four step residual overcurrent protection.
+ =
40 ms 40 ms 220 ms
is 100 ms
is 40 ms and
is 40 ms
IEC 61850
identification
EF4PTOC
Section 7
Current protection
IEC 60617 ANSI/IEEE C37.2
identification device number
51N_67N
4(IN>)
4
alt
4
TEF-REVA V2 EN
(Equation 38)
183