ABB Relion 670 series - Setting Guidelines

unsymmetrical check on the line where the IED connected will give alarm or trip at
detecting broken conductors.
9.12.3 Setting guidelines
Broken conductor check BRCPTOC (46) must be set to detect open phase/s (series faults)
with different loads on the line. BRCPTOC (46) must at the same time be set to not operate
for maximum asymmetry which can exist due to, for example, not transposed power lines.
All settings are in primary values or percentage.
Set IBase (given in GlobalBaseSel) to power line rated current or CT rated current.
Set minimum operating level per phase Pickup_PH to typically 10-20% of rated current.
Set the unsymmetrical current, which is relation between the difference of the minimum
and maximum phase currents to the maximum phase current to typical Pickup_ub = 50%.
Note that it must be set to avoid problem with asymmetry under minimum
operating conditions.
Set the time delay tOper = 5 - 60 seconds and reset time tReset = 0.010 - 60.000 seconds.
9.13 Voltage-restrained time overcurrent protection
VRPVOC (51V)
9.13.1 Identification
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Voltage-restrained time overcurrent
protection
VRPVOC I>/U< 51V
9.13.2 Application
A breakdown of the insulation between phase conductors or a phase conductor and ground
results in a short-circuit or a ground fault. Such faults can result in large fault currents and
may cause severe damage to the power system primary equipment.
A typical application of the voltage-restrained time overcurrent protection is in the
generator protection system, where it is used as backup protection. If a phase-to-phase
1MRK 506 369-UUS - Section 9
Current protection
Line distance protection REL670 2.2 ANSI 561
Application manual