U.1.19
Date Code 20090715
User’s Guide
SEL-421 Relay
Introduction and Specifications
Specifications
Reactive Power, Q (MVAR), Three Phase
At 0.1 • I
nom
Power factor 0.5 lag,
0.5 lead:
±0.5%
At 1.0 • I
nom
Power factor 0.5 lag,
0.5 lead:
±0.4%
Energy (MWh), Three Phase
At 0.1 • I
nom
Power factor unity:
±0.5%
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%
Synchrophasors
See
for test exclusions and details.
TVE (total vector error):
≤1%
Frequency Range:
±5 Hz of nominal (50 or 60 Hz)
Voltage Range:
30 V–150 V
Current Range:
(0.1–2) • I
nom
(I
nom
= 1 A or 5 A)
Phase Angle Range:
–179.99° to 180°
Summary of Contents for 421
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