WEG AVR-A-OPT-03 Installation, Operation And Maintenance Manual page 29

24 SPECIFICATIONS OF PT FOR POWER SUPPLY
The use of PT for power supply is recommend if an auxiliary coil is not been used and the available voltage for power
supply is bigger than 250Vac. Some characteristics of the PT follow bellow:

The power supply of the PT will always be single-phase;

Impedance of 4% and powder coated shield;

Power of 1KVA;

The transformation relation will be of N/220, where N is the generator's output voltage;
 The class of the voltage insulation of the PT must be greater than the generator's output voltage;

Single-phase connection type.
25 SPECIFICATION OF PT 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. It means, over 600V there must be used one PT. Some characteristics of the PT follow bellow:

When the power supply is single-phase, only one PT is used. In case of three-phase power supply there are used three
single-phase PT´s connected in YY;

The transformation relation will be of N/220, where N is the generator's output voltage;

The power loss will be of 100VA;

The class of the voltage isolation of the PT must be greater than the generator's output voltage.
26 SPECIFICATION OF THE CT FOR PARALLELISM
Some characteristics of the CT for parallelism follow bellow:

Precision class of 0,6C12,5;

Window or bar type;

Current of the secondary of 5A;

The current of the primary of the CT must be 20% greater than the rated current of the machine;
 The working frequency of the CT must be the same as the generator's frequency;

The transformation relation will be IN/5A, where IN is the relation for the primary of the CT.

Ex.: 100/5A, 150/5A;
 The class of the voltage isolation of the CT must be greater than the generator's output voltage;

Thermo factor of 1.2 x In.
27 PREVENTIVE MAINTENANCE
It is necessary to proceed with periodic inspections at the unit to make sure that the AVR is clean and free of dust and
other detritus. It's essential that all terminals and wire connections are maintained free of corrosion.
28 WARRANTY
See the Installation and Maintenance Manual of the alternator WEG.
Analog Voltage Regulator AVR-A-OPT-03
www.weg.net
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