Schweitzer Engineering Laboratories SEL-351 - Metering Accuracy; Substation Battery Voltage Monitor; Under- and Overfrequency Elements

Date Code 20001006 Introduction and Specifications 1-19
SEL-351 Instruction Manual
Under- and Overfrequency Elements
Pickup Range: 40.10 - 65.00 Hz, 0.01 Hz steps
Steady-State plus Transient Overshoot: ±0.01 Hz
Time Delay: 2.00 - 16,000.00 cycles, 0.25-cycle steps
Timer Accuracy: ±0.25 cycle and ±0.1% of setting
Timers
Pickup Ranges: 0.00 - 999,999.00 cycles, 0.25-cycle steps
(reclosing relay and some programmable timers)
0.00 - 16,000.00 cycles, 0.25-cycle steps (some
programmable and other various timers)
Pickup and dropout accuracy for all timers: ±0.25 cycle and ±0.1% of setting
Substation Battery Voltage Monitor
Pickup Range: 20 - 300 Vdc, 1 Vdc steps
Pickup Accuracy: ±2% of setting
Metering Accuracy
Accuracies are specified at 20°C and at nominal system frequency unless noted otherwise.
Voltages V
A
, V
B
, V
C
, V
S
, 3V
0
, V
1
, V
2
V
AB
, V
BC
, V
CA
, V
S
, V
1
, V
2
±0.1% (33.5 - 150 V; wye-connected)
{150 V voltage inputs}
±0.2% (67.0 - 300 V; wye-connected)
{300 V voltage inputs}
±0.3% (33.5 - 260 V; delta-connected)
{150 V voltage inputs}
Currents I
A
, I
B
, I
C
±1 mA and ±0.1% (0.5 - 10 A) (5 A nominal)
±0.2 mA and ±0.1% (0.1 - 2 A) (1 A nominal)
Temperature coefficient:
[(0.0002%)/(°C)
2
] * (__°C - 20°C)
2
(see example below)
Currents I
N
, I
1
, 3I
0
, 3I
2
±0.05 A and ±3% (0.5 - 100 A) (5 A nominal)
±0.01 A and ±3% (0.1 - 20 A) (1 A nominal)
±1 mA and ±5% (0.01 - 1.5 A) (0.05 A nominal
channel IN current input)
Phase Angle Accuracy ±0.5°
Courtesy of NationalSwitchgear.com