sepam 20 user manual - Schneider Electric

Metering functions Residual voltage
Positive sequence voltage
PCRED301005EN - 06/2008
Residual voltage
Operation
This function gives the value of the residual voltage V0 = (V1 + V2 + V3).
V0 is measured:
b by taking the internal sum of the 3 phase voltages
b by an open star / delta VT.
It is based on measurement of the fundamental component.
Readout
The measurement may be accessed via:
b the display of a Sepam with advanced UMI by pressing the key
b the display of a PC with the SFT2841 software
b the communication link.
Characteristics
Measurement range 0.015 Vnp to 3 Vnp (1)
Unit V or kV
Accuracy ±1 % from 0.5 to 3 Vnp
±2 % from 0.05 to 0.5 Vnp
±5 % from 0.015 to 0.05 Vnp
Display format 3 significant digits
Resolution 1 V or 1 digit
Refresh interval 1 second (typical)
(1) Vnp: primary rated phase-to-neutral voltage (Vnp = Unp/3).
Positive sequence voltage
Operation
This function gives the calculated value of the positive sequence voltage Vd.
Readout
The measurement may be accessed via:
b the display of a Sepam with advanced UMI by pressing the key
b the display of a PC with the SFT2841 software
b the communication link.
Characteristics
Measurement range 0.05 to 1.2 Vnp (1)
Unit V or kV
Accuracy ±2 % at Vnp
Display format 3 significant digits
Resolution 1 V or 1 digit
Refresh interval 1 second (typical)
(1) Vnp: primary rated phase-to-neutral voltage (Vnp = Unp/3).
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