ABB RET 543 - Page 58

Fig. 13 Symbol notations, part I
3I > 50/51
3I> 67
I
0
>
50N/51N
3U > 59
3U < 27
U
0
>
59N
3I
2f
>
68
CBFP 62BF
I
2
>
46
3D I >
87T
DI
0
>
87TN
SYMNOT1_RET
U < 27
3D I >
87TG
U/f 24
I(U)> 51V
I
0S
> 64S
I
0R
> 64R
f >
df/dt
81U
81U-R
f <
df/dt
81O
81O-R
f>/f<
81O
81U
49T
3
49
38
Q>
f >
81U
3
49G
= multiple-stage three-phase overcurrent protection, double low-set, high-set
and instantaneous stages available (NOC3_)
= multiple-stage three-phase directional overcurrent protection, low-set, high-set and
instantaneous stage available (DOC6_)
= multiple-stage earth-fault protection, low-set, high-set and instantaneous stage
available (NEF1_)
= three-phase overvoltage protection, low-set and high-set stage available (OV3_)
= three-phase undervoltage protection, low-set and high-set stage available (UV3_)
= multiple-stage residual overvoltage protection, low-set, high-set and instantaneous
stage available (ROV1_)
= inrush detection based on the 2nd harmonic content of phase currents, applied for
preventing possible unnecessary operation of overcurrent or earth-fault protection
during transformer switching-in or to start cold load pick-up logic (Inrush3_)
= negative phase sequence (NPS) protection,
low-set and high-set stages available (NPS3_)
= underfrequency protection and frequency rate of change function (incl. in Freq1St_)
= three phase differential protection for transformers, stabilized and instantaneous
stages (Diff3)
= restricted earth-fault (REF) protection, low- or high-impedance type (Diff3)
= circuit-breaker failure protection (included in all current-based
short circuit and earth-fault protection function blocks)
= undervoltage protection, low-set and high-set stage available (UV3_)
= overall differential protection for generator and transformer blocks, stabilized and
instantaneous stages (Diff6T)
= overexcitation protection, low-set and high-set stages available (OE1_)
= voltage-dependent overcurrent protection, low-set and high-set stages
available (VOC6_)
= stator earth-fault protection (NEF1_)
= rotor earth-fault protection (NEF1_)
= overfrequency protection and frequency rate of change function (incl. in Freq1St_)
= over/underfrequency protection (incl. in Freq1St_)
=
three-phase thermal overload protection for transformers (TOL3Dev)
= thermal supervision for generator windings and bearings with RTDs (MEAI_)
= overfrequency protection (incl. in Freq1St_)
= three-phase thermal overload protection for generator (TOL3Dev)
Transformer Terminal RET 541, RET 543, RET 545
1MRS755543
58