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350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
S3 PROTECTION
CHAPTER 6: SETPOINTS
CURRENT PICKUP
Range: 0.002 to 20.000 x CT in steps of 0.001 x CT
Default: 0.060 x CT
This setpoint specifies the neutral current supervision level for the measurement of zero
sequence power.
When the CURRENT setpoint value is Measured Ig, 1 x CT is the GROUND [SENS GND] CT
PRIMARY setpoint value. When the CURRENT setpoint value is Calculated In, 1 x CT is the
PHASE CT PRIMARY setpoint value.
POWER PICKUP
Range: 0.001 to 1.200 CTxVT in steps of 0.001 CTxVT
Default: 0.100 CTxVT
This setpoint specifies the operating point of the element.
A value of 1 CTxVT is a product of the 1 x VT voltage as specified in the VOLTAGE PICKUP
setpoint description of this element, and 1 x CT current as specified for the CURRENT
PICKUP setpoint of this element.
REF POWER PICKUP
Range: 0.001 to 1.200 CTxVT in steps of 0.001 CTxVT
Default: 0.100 CTxVT
This setpoint is used to calculate the inverse time characteristic delay (defined by Sref in
the equations below).
A value of 1 CTxVT is a product of the 1 VT voltage as specified in the VOLTAGE PICKUP
setpoint description of this element, and 1 CT current as specified for the CURRENT
PICKUP setpoint of this element.
ECA
Range: 0 to 359° in steps of 1°
Default: 0°
The setpoint adjusts the maximum torque angle of the element. The operating power is
calculated as:
Eq. 11
Where * indicates complex conjugate and · indicates simple vector multiplication.
By varying the element characteristic angle (ECA), the element can be made to respond
to forward or reverse direction in inductively, resistively, or capacitively grounded
networks as shown in the Wattmetric characteristic angle response diagram below.