Sel SEL-421 - Page 59

U.1.13
Date Code 20020501 User’s Guide SEL-421/SEL-421-1 Relay
Introduction and Specifications
Specifications
(Minimum sensitivity is controlled by
the pickup of the supervising phase
and residual overcurrent elements for
each zone.)
Accuracy (Steady State): ±3% of setting at line angle for SIR < 30
±5% of setting at line angle for
30 £ SIR £ 60
Zone 1 Transient
Overreach: < 5% of setting plus
steady state accuracy
SEL-421 Maximum
Operating Time: 0.8 cycle at 70% of reach and SIR = 1
SEL-421-1 Maximum
Operating Time: 1.5 cycle at 70% of reach and SIR = 1
Quadrilateral Ground Distance Elements
Zones 1–5 Impedance Reach
Quadrilateral
Reactance Reach:
5 A Model: OFF, 0.05 to 64 W secondary, 0.01 W steps
1 A Model: OFF, 0.25 to 320 W secondary,
0.01 W steps
Quadrilateral
Resistance Reach:
5 A Model: OFF, 0.05 to 50 W secondary, 0.01 W steps
1 A Model: OFF, 0.25 to 250 W secondary,
0.01 W steps
Sensitivity:
5 A Model: 0.5 A secondary
1 A Model: 0.1 A secondary
(Minimum sensitivity is controlled by
the pickup of the supervising phase and
residual overcurrent elements for each
zone.)
Accuracy (Steady State): ±3% of setting at line angle for SIR < 30
±5% of setting at line angle for
30 £ SIR £ 60
Transient Overreach: < 5% of setting plus steady state accuracy
Instantaneous/Definite-Time Overcurrent Elements
Phase, Residual Ground, and Negative-Sequence
Pickup Range:
5 A Model: OFF, 0.25–100.00 A secondary,
0.01 A steps
1 A Model: OFF, 0.05–20.00 A secondary,
0.01 A steps
Accuracy (Steady State):
5 A Model: ±0.05 A plus ±3% of setting
1 A Model: ±0.01 A plus ±3% of setting
Transient Overreach: < 5% of pickup
Time Delay: 0.00–16000.00 cycles, 0.125 cycle steps
Timer Accuracy: ±0.125 cycle plus ±0.1% of setting
Maximum
Operating Time: 1.5 cycles
Note: See pickup and reset time curves in the Inverse Time-Overcurrent
Elements on page R.1.69 in the Reference Manual.
Time-Overcurrent Elements
Pickup Range:
5 A Model: 0.50–16.00 A secondary, 0.01 A steps
1 A Model: 0.10–3.20 A secondary, 0.01 A steps
Accuracy (Steady State):
5 A Model: ±0.05 A plus ±3% of setting
1 A Model: ±0.01 A plus ±3% of setting
Time Dial Range:
US: 0.50–15.00, 0.01 steps
IEC: 0.05–1.00, 0.01 steps
Curve Timing Accuracy: ±1.50 cycles plus ±4% of curve time
(for current between 2 and 30
multiples of pickup)
Reset: 1 power cycle or Electromechanical
Reset Emulation time
Ground Directional Elements
Neg.-Seq. directional
impedance threshold (Z2F, Z2R):
5 A Model: –64 to 64 W
1 A Model: –320 to 320 W
Zero-Seq. directional
impedance threshold (Z0F, Z0R)
5 A Model: –64 to 64 W
1 A Model: –320 to 320 W
Supervisory overcurrent
pickup 50FP, 50RP:
5 A Model: 0.25 to 5.00 A 3I0 secondary
0.25 to 5.00 A 3I2 secondary
1 A Model: 0.05 to 1.00 A 3I0 secondary
0.05 to 1.00 A 3I2 secondary
Undervoltage and Overvoltage Elements
Pickup Ranges: Phase elements: 1–200 V secondary,
1 V steps
Phase-to-phase elements: 1.0–300.0 V secondary, 0.1 V steps
Accuracy (Steady State): ±1 V plus ±5% of setting
Transient Overreach: < 5% of pickup
Breaker Failure Instantaneous Overcurrent
Setting Range:
5 A Model: 0.50–50.0 A, 0.01 A steps
1 A Model: 0.10–10.0 A, 0.01 A steps
Accuracy:
5 A Model: ±0.05 A plus ±3% of setting
1 A Model: ±0.01 A plus ±3% of setting
Transient Overreach: < 5% of setting
Maximum Pickup Time: 1.5 cycles
Maximum Reset Time: 1 cycle
Timers Setting Range: 0–6000 cycles, 0.125 cycle steps
(All but BFIDOn, BFISPn)
0–1000 cycles, 0.125 cycle steps
(BFIDOn, BFISPn)
Time Delay Accuracy: 0.125 cycle plus ±0.1% of setting
Synchronism-Check Elements
Slip Frequency
Pickup Range: 0.005–0.500 Hz, 0.001 Hz steps
Slip Frequency
Pickup Accuracy: ±0.0025 Hz plus ±2% of setting
Close Angle Range: 3–80°, 1° steps
Close Angle Accuracy: ± 3°
Load-Encroachment Detection
Setting Range:
5 A Model: 0.05–64 W secondary, 0.01 Wsteps
1 A Model: 0.25–320 W secondary, 0.01 Wsteps
Forward Load Angle: –90° to +90°
Reverse Load Angle: +90° to +270°
Accuracy:
Impedance measurement: ±3%
Angle measurement: ±2°
Out-of-Step Elements
Blinders (R1) parallel to the line angle:
5 A Model: 0.05 to 70 W secondary
–0.05 to –70 W secondary
1 A Model: 0.25 to 350 W secondary
–0.25 to –350 W secondary
Blinders (X1) perpendicular to the line angle:
5 A Model: 0.05 to 96 W secondary
–0.05 to –96 W secondary
1 A Model: 0.25 to 480 W secondary
–0.25 to –480 W 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