Pt Specification For Power Supply; Pt Specification For Sensing Voltage; Ct Specification For Parallelism - WEG WRGA-02 Manual De Instalación, Operación Y Mantenimiento

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25.

PT SPECIFICATION FOR POWER SUPPLY

Using a PT for power supply is recommend if an auxiliary coil will not be used and the available voltage for power supply is
different from the voltage range of the regulator power supply. Some characteristics of the PT are shown below:
The power supply of the PT will always be single-phase;
Impedance of 4% and electrostatic shield;
Power of 1KVA;
The transformer ratio will be N/220, where N is the regulator's source of power (generator output voltage, grid, etc) ;
The insulation voltage class of the PT must be greater than the highest voltage , be it primary or secondary;
Single-phase connection type.
26.

PT SPECIFICATION FOR SENSING VOLTAGE

The PT for sensing voltage is recommended if the available voltage for the signal is higher than the one specified by the
regulator. This means that over 600V, a PT must be used. Some characteristics of the PT are as follows:
When the power supply is single-phase, only one PT is used. In case
The transformation relation will be of N/220, where N is the generator's output voltage;
The power will be of 100VA;
The class of the voltage isolation of the PT must be greater than the generator's output voltage.
27.

CT SPECIFICATION FOR PARALLELISM

Some characteristics of the CT for parallelism are shown below:
Accuracy class of 0,6C12,5;
Window or bar type;
5A secondary current;
he CT primary current must be 20% greater than the rated current of the Generator;
The working frequency of the CT must be the same as the generator frequency;
The transformer ratio will be IN/5A, where IN is the ratio of the primary of the CT.
Ex.: 100/5A, for a generator with rated current of 100A, 150/5A for generator with rated current of 150A; It is important and
necessary to correctly configure the regulator in accordance with the rated current of the external CT being used.
The class of the voltage isolation of the CT must be greater than the generator's output voltage;
Thermal resistance of 1,2 x IN.
34 l Automatic Voltage Regulator – GRT7-TH4-R2