Four Step Single Phase Overcurrent Protection Ph4Sptoc (51); Identification; Application - ABB REB670 Applications Manual

1MRK 505 370-UUS A
7.2
7.2.1
7.2.2
Busbar protection REB670 2.2 ANSI
Application manual
D ³ + +
t 40 ms 100 ms
EQUATION1266 V1 EN-US
where it is considered that:
the operate time of overcurrent protection B1 is 40 ms
the breaker open time
the resetting time of protection A1
the additional margin
Four step single phase overcurrent protection
PH4SPTOC (51)

Identification

Function description
Four step single phase overcurrent
protection

Application

The Four step single phase overcurrent protection(PH4SPTOC, 51) function is used in
several applications in the power system. Some applications are:
• Short circuit protection of feeders in distribution and subtransmission systems.
Normally these feeders have radial structure.
• Back-up short circuit protection of transmission lines.
• Back-up short circuit protection of power transformers
• Short circuit protection of different kinds of equipment connected to the power
system such as; shunt capacitor banks, shunt reactors, motors and others.
• Back-up short circuit protection of power generators.
The single phase overcurrent protection is used in IEDs having only input from one
phase, for example busbar protection for large busbars (with many bays).
+ =
40 ms 40 ms 220 ms
is 100 ms
is 40 ms and
is 40 ms
IEC 61850
identification
PH4SPTOC
Section 7
Current protection
IEC 60617 ANSI/IEEE C37.2
identification device number
51
I>
4
alt
4
OC V1 EN-US
(Equation 29)
SEMOD127812-1 v2
SEMOD127810-2 v2
SEMOD127937-4 v2
187