1.14
SEL-351S Relay Instruction Manual Date Code 20080103
Introduction and Specifications
Specifications
MW / MVAR
(A, B, C, and 3-phase; 5 A nominal; wye connected voltages)
MW / MVAR(3-phase; 5 A nominal; open-delta connected
voltages; balanced conditions)
Accuracy
(MW / MVAR)
at load angle
for 0.5 A sec. ≤ phase current < 1.0 A sec.:
0.70% / – 0° or 180° (unity power factor)
0.75% / 6.50% ±8° or ±172°
1.00% / 2.00% ±30° or ±150°
1.50% / 1.50% ± 45° or ± 135°
2.00% / 1.00% ±60° or ±120°
6.50% / 0.75% ±82° or ±98°
– / 0.70% ± 90° (power factor = 0)
for phase current ≥ 1.0 A sec.:
0.35% / – 0° or 180° (unity power factor)
0.40% / 6.00% ± 8 or ±172°
0.75% / 1.50% ±30° or ±150°
1.00% / 1.00% ±45° or ±135°
1.50% / 0.75% ±60° or ±120°
6.00% / 0.40% ±82° or ±98°
– / 0.35% ± 90° (power factor = 0)
Metering accuracy calculation example for currents I
A
, I
B
, and I
C
is based on preceding stated temperature coefficient:
For temperature of 40°C, the additional error for currents I
A
, I
B
,
and I
C
is:
[(0.0002%)/(°C)
2
] • (40°C – 20°C)
2
= 0.08%
Synchrophasor Accuracy
(Specification is with respect to MET PM command and SEL Fast
Message Synchrophasor Protocol.)
Voltages (33.5–150 V; 45–65 Hz)
(150 V nominal)
(33.5–300 V; 45–65 Hz)
(300 V nominal)
Magnitudes: ± 2%
Angles: ±1°
Currents (0.50–1.25 A; 45–65 Hz) (5 A nominal)
(0.10–0.25 A; 45–65 Hz) (1 A nominal)
Magnitudes: ±4%
Angles: ±1.5° at 25°C
±2.0° over the full temperature range
Currents (1.25–7.50 A; 45–65 Hz) (5 A nominal)
(0.25–2.50 A; 45–65 Hz) (1 A nominal)
Magnitudes: ±2%
Angles: ±1.0° at 25°C
±1.5° over the full temperature range
Power Element Accuracy
Single-phase power elements:
Pickup:
Pickup setting
0.33–2 VA
{5 A nominal},
0.07–0.4 VA
{1 A nominal}
±0.05 A • (L-N voltage secondary)
and ±10% of setting at unity
power factor for power elements
and zero power factor for reactive
power element {5 A nominal}
±0.01 A • (L-N voltage secondary)
and ±10% of setting at unity
power factor for power elements
and zero power factor for reactive
power element {1 A nominal}
Pickup setting
2–13000 VA
{5 A nominal},
0.4–2600 VA
{1 A nominal}
±0.025 A • (L-N voltage secondary)
and ±5% of setting at unity power
factor {5 A nom}
±0.005 A • (L-N voltage secondary)
and ±5% of setting at unity power
factor {1 A nom}
Three-phase power elements:
Pickup:
Pickup setting
1–6 VA
{5 A nominal},
0.2–1 VA
{1 A nominal}:
±0.05 A • (L-L voltage secondary)
and ±10% of setting at unity
power factor for power elements
and zero power factor for reactive
power element {5 A nominal}
±0.01 A • (L-L voltage secondary)
and ±10% of setting at unity
power factor for power elements
and zero power factor for reactive
power element {1 A nominal}
Pickup setting
6–39000 VA
{5 A nominal},
1–7800 VA
{1 A nominal}:
±0.025 A • (L-L voltage secondary)
and ±5% of setting at unity power
factor for power elements and zero
power factor for reactive power
element {5 A nominal}
±0.005 A • (L-L voltage secondary)
and ±5% of setting at unity power
factor for power elements and zero
power factor for reactive power
element {1 A nominal}
The quoted three-phase power element accuracy specifications are
applicable as follows:
Wye-connected voltages (PTCONN = WYE): any conditions
Open-delta connected voltages (PTCONN = DELTA), with
properly configured broken-delta 3V0 connection (VSCONN =
3V0): any conditions
Open-delta connected voltages, without broken-delta 3V0
connection (VSCONN = VS): balanced conditions only
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