Metering Function - Toshiba GRT100 Series Instruction Manual

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3.5 Metering Function

The GRT100 performs continuous measurement of the analogue input quantities. The
measurement data shown below are displayed on the LCD of the relay front panel or on the local
or remote PC.
- Magnitude and phase angle of phase current of each winding (I a1 , I b1 , I c1 up to I a3 , I b3 , I c3 )
- Magnitude and phase angle of neutral current of each winding (I n1 up to I n3 )
- Magnitude and phase angle of symmetrical component current of each winding (I 11 , I 21 , I 01
up to I 13 , I 23 , I 03 )
- Magnitude and phase angle of phase-to-phase voltage (V)
- Magnitude of phase differential current (I da, I db, I dc )
- Magnitude of residual differential current for REF protection (I d01 up to I d03 )
- Frequency
Phase angles above are expressed taking that of positive sequence voltage as a reference phase
angle, where leading phase angles are expressed plus.
The above system quantities are displayed in values on the primary side or on the secondary side
of the CT by the setting. To display accurate values, it is necessary to set the CT ratio and VT
ratio too. For the setting method, see "Setting the transformer parameters" in 4.2.6.7.
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