Symbol Notations - ABB REX 521 Technical Reference Manual, Standard Configurations

1MRS 751802-MUM
12.
Protection Relay
Technical Reference Manual, Standard Configurations

Symbol notations

= multiple-stage three-phase overcurrent protection, low-set, high-set and instantaneous
3I > 50/51
stage available
= multiple-stage three-phase directional overcurrent protection, low-set, high-set and
3I>
67
instantaneous stage available
= multiple-stage earth-fault protection, low-set, high-set and instantaneous stage
I >
50N/51N
available
0
= multiple-stage directional earth-fault protection, low-set, high-set and instantaneous
I > 67N
stage available
0
= three-phase overvoltage protection, low-set and high-set stage available
3U > 59
= three-phase undervoltage protection, low-set and high-set stage available
3U < 27
= multiple-stage residual overvoltage protection, low-set, high-set and instantaneous
U > 59N
stage available
0
= inrush detection based on the 2nd harmonic content of phase currents, applied for
3I > 68
preventing possible unnecessary operation of overcurrent or earth-fault protection
2f
during transformer switching-in or to start cold load pick-up logic
= phase discontinuity protection
DI>
46
= thermal overload protection for feeders
3
49F
= under/overfrequency protection/load shedding scheme
f </f>
81U/81O
= multiple-shot auto-recloser
0 79
I
= circuit breaker synchro-check/direction of energizing check function
SYNC 25
= circuit-breaker failure protection
CBFP * /62
= lockout (Refer to chapter “Lockout function” in this manual)
86
LO
= voltage waveform distortion measurement
3U~harm
= current waveform distortion measurement
3I~harm
= annunciating, event generating and value recording functions
R
= disturbance recorder
= digital value indication
000
= local and remote control interface
0 I
REX 521
SYMNOTREX
201