Sel 421 - Page 60

U.1.18
SEL-421 Relay User’s Guide Date Code 20090715
Introduction and Specifications
Specifications
Out-of-Step Elements
Blinders (R1) Parallel to the Line Angle
5 A Model: 0.05 to 70 Ω secondary
–0.05 to –70 Ω secondary
1 A Model: 0.25 to 350 Ω secondary
–0.25 to –350 Ω secondary
Blinders (X1) Perpendicular to the Line Angle
5 A Model: 0.05 to 96 Ω secondary
–0.05 to –96 Ω secondary
1 A Model: 0.25 to 480 Ω secondary
–0.25 to –480 Ω secondary
Accuracy (Steady State)
5 A Model: ±5% of setting plus ±0.01 A for SIR
(source to line impedance ratio) < 30
±10% of setting plus ±0.01 A for 30
≤ SIR ≤ 60
1 A Model: ±5% of setting plus ±0.05 A for SIR
(source to line impedance ratio) < 30
±10% of setting plus ±0.05 A for
30 ≤SIR ≤ 60
Transient Overreach: <5% of setting plus steady-state
accuracy
Positive-Sequence Overcurrent Supervision
Setting Range
5 A Model: 1.0–100.0 A, 0.01 A steps
1 A Model: 0.2–20.0 A, 0.01 A steps
Accuracy
5 A Model: ±3% of setting plus ±0.05 A
1 A Model: ±3% of setting plus ±0.01 A
Transient Overreach: < 5% of setting
Timer Specifications
Setting Ranges
Breaker Failure: 0–6000 cycles, 0.125 cycle steps
(All but BFIDOn, BFISPn)
0–1000 cycles, 0.125 cycle steps
(BFIDOn, BFISPn)
Communications-
Assisted Tripping
Schemes: 0.000–16000 cycles, 0.125 cycle steps
Out-of-Step Timers
OSBD, OSTD: 0.500–8000 cycles, 0.125 cycle steps
UBD: 0.500–120 cycles, 0.125 cycle steps
Pole Open Timer: 0.000–60 cycles, 0.125 cycle steps
Recloser: 1–99999 cycles, 1 cycle steps
Switch-Onto-Fault
CLOEND, 52AEND: OFF, 0.000–16000 cycles,
0.125 cycle steps
SOTFD: 0.50–16000 cycles, 0.125 cycle steps
Synchronism Check Timers
TCLSBK1, TCLSBK2: 1.00–30.00 cycles, 0.25 cycle steps
Zone Time Delay: 0.000–16000 cycles, 0.125 cycle steps
Station DC Battery System Monitor Specifications
Operating Range: 0–350 Vdc
Input Sampling Rate: 2 kHz
Processing Rate: 1/8 cycle
Maximum
Operating Time:
≤1.5 cycles
Setting Range
DC settings: 15–300 Vdc, 1 Vdc steps
AC ripple setting: 1–300 Vac, 1 Vac steps
Accuracy
Pickup Accuracy: ±3% plus ±2 Vdc (all elements but
DC1RP and DC2RP)
±10% plus ±2 Vac (DC1RP and
DC2RP)
Metering Accuracy
All metering accuracy is at 20°C, and nominal frequency unless
otherwise noted.
Currents
Phase Current Magnitude
5 A Model: ±0.2% plus ±4 mA (2.5–15 A sec)
1 A Model: ±0.2% plus ±0.8 mA (0.5–3 A sec)
Phase Current Angle
All Models: ±0.2° in the current range 0.5 • I
nom
to
3.0 • I
nom
Sequence Currents Magnitude
5 A Model: ±0.3% plus ±4 mA (2.5–15 A sec)
1 A Model: ±0.3% plus ±0.8 mA (0.5–3 A sec)
Sequence Current Angle
All Models: ±0.3° in the current range 0.5 • I
nom
to
3.0 • I
nom
Voltages
Phase and
Phase-to-Phase Voltage
Magnitude: ± 0.1% (33.5–200 V
L-N
)
Phase and
Phase-to-Phase Angle: ±0.05° (33.5–200 V
L-N
)
Sequence Voltage
Magnitude: ±0.15% (33.5–200 V
L-N
)
Sequence Voltage Angle: ±0.1° (33.5–200 V
L-N
)
Frequency (Input 40–65 Hz)
Accuracy: ±0.01 Hz
Power and Energy
Real Power, P (MW), Three Phase
At 0.1 • I
nom
Power factor unity: ±0.4%
Power factor 0.5 lag,
0.5 lead:
±0.7%
At 1.0 • I
nom
Power factor unity: ±0.4%
Power factor 0.5 lag,
0.5 lead:
±0.4%
Courtesy of NationalSwitchgear.com