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Date Code 990430 Overcurrent, Voltage, Synchronism Check, and Frequency Elements 3-1
SEL-351P Manual Técnico
SECTION 3:
OVERCURRENT, VOLTAGE, SYNCHRONISM
CHECK, AND FREQUENCY ELEMENTS
Many of the elements described in this section are used in the factory-set logic for the SEL-351P
Recloser Control. Refer to Table1.1 in
Section 1: Factory-Set Logic for the correlation between
the EZ settings that drive this factory-set logic and the “regular” settings that set many of the
elements in this section. Refer to Table 1.2 in
Section 1: Factory-Set Logic for the functions of
the overcurrent elements when the factory default EZ settings are active for a particular setting
group.
I
NSTANTANEOUS
/D
EFINITE
-T
IME
O
VERCURRENT
E
LEMENTS
Phase Instantaneous/Definite-Time Overcurrent Elements
Four levels of phase instantaneous/definite-time overcurrent elements are available. Two
additional levels of phase instantaneous overcurrent elements (Levels 5 and 6) are also available.
The different levels are enabled with the E50P enable setting, as shown in Figure SECTION 3:
.1, Figure SECTION 3: .2, and Figure SECTION 3: .3.
Level 2 element 67P2S in Figure SECTION 3: .3 is used in directional comparison blocking
schemes (see
Directional Comparison Blocking (DCB) Logic in Section 5: Trip and Target
Logic ). All the other phase instantaneous/definite-time overcurrent elements are available for
use in any tripping or control scheme.
Settings Ranges
Setting range for pickup settings 50P1P through 50P6P:
0.05 - 20.00 A secondary (1 A nominal phase current inputs, IA, IB, IC)
Setting range for definite-time settings 67P1D through 67P4D:
0.00 - 16000.00 cycles, in 0.25-cycle steps
Setting range for definite-time setting 67P2SD (used in the DCB logic):
0.00 - 60.00 cycles, in 0.25-cycle steps
Accuracy
Pickup:
±
0.01 A secondary and
±
3% of setting (1 A nominal phase current inputs, IA, IB, IC)
Timer:
±
0.25 cycles and
±
0.1% of setting
Transient Overreach:
±
5% of setting