Schweitzer Engineering Laboratories SEL-787 - Page 36

1.12
SEL-787 Relay Instruction Manual Date Code 20081022
Introduction and Specifications
Specifications
Metering Accuracy
Accuracies are specified at 20°C, nominal frequency, ac currents
within (0.2–2.0) • I
NOM
A secondary, and ac voltages within
50–250 V secondary unless otherwise noted.
Phase Currents: ±1% of reading, ±1° (±2.5° at 0.2–0.5 A
for relays with Inom = 1 A)
3-Phase Average Current: ±2% of reading
Differential Quantities: ±5% of reading, ±0.1 A (5 A nominal),
±0.02 A (1 A nominal)
Current Harmonics: ±5% of reading, ±0.1 A (5 A nominal),
±0.02 A (1 A nominal)
IG (Residual Current): ±3% of reading, ±2° (±5.0° at 0.2–0.5 A
for relays with Inom = 1 A)
IN (Neutral Current): ±1% of reading, ±1° (±2.5° at 0.2–0.5 A
for relays with Inom = 1 A)
3I2 Negative-Sequence
Current: ±3% of reading
System Frequency: ±0.1 Hz of reading for frequencies
within 20–70 Hz (requires ac voltage
inputs option)
Line-to-Line Voltages: ±2% of reading, ±1° for voltages
within 24–264 V
3-Phase Average Line-to-
Line Voltage:
±2% of reading for voltages
within 24–264 V
Line-to-Ground Voltages: ±2% of reading, ±1° for voltages
within 24–264 V
3-Phase Average Line-to-
Ground Voltages:
±2% of reading for voltages
within 24–264 V
Voltage Harmonics: ±5% of reading, ±0.5 V
3V2 Negative-Sequence
Voltage:
± 3% of reading for voltages
within 24–264 V
Real 3-Phase Power (kW): ± 3% of reading for 0.10 < pf < 1.00
Reactive 3-Phase
Power (kVAR): ± 3% of reading for 0.00 < pf < 0.90
Apparent 3-Phase
Power (kVA): ± 3% of reading
Power Factor: ±2% of reading for 0.86 ≤ pf ≤ 1
RTD Temperatures: ±2°C