ABB REB670 - Four Step Single Phase Overcurrent Protection PH4 SPTOC (51); Identification; Application

40 100 40 40 220t ms ms ms ms msD ³ + + + =
EQUATION1266 V1 EN-US (Equation 29)
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
7.2 Four step single phase overcurrent protection
PH4SPTOC (51)
SEMOD127812-1 v2
7.2.1
Identification
SEMOD127810-2 v2
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Four step single phase overcurrent
protection
PH4SPTOC
4
4
alt
I>
OC V1 EN-US
51
7.2.2 Application
SEMOD127937-4 v2
The Four step single phase overcurrent protection(PH4SPT
OC, 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).
1MRK 505 370-UUS A Section 7
Current protection
Busbar protection REB670 2.2 ANSI 187
Application manual