VT Accuracy Class

The two numbers are the burden/accuracy class combination.

http://www.gedigitalenergy.com/products/brochures/ititechinfo.pdf

http://www.ritz-international.com/fileadmin/pictures/cms/pdf/downloads/VoltageInstrumentTransformerMediumVoltageBlock.pdf

It means that the VT has two windings; the first winding belongs to an accuracy class of 0.2 (i.e.) it will maintain its accuracy of +/- 0.2% ratio error between 80% to 120%of the rated primary voltage. Normally this is used for metering purposes.

The second winding belongs to an accuracy class of 3P, which means that it would maintain its accuracy of +/-3% ratio error between 5% to the rated voltage factor. This is used for protection purposes.

Thank you for information. But for 0.2 accuracy I understood like this ie for eg if pt ratio is 380 kV/115 V, if we are applying 380 kV on primary the secondary should be 99.8%of 115 to 100.2% of 115. If the ratio is inside the limit its following its class.isn't it, correct me if am wrong

Your understanding is correct. Accuracy class 0.2 means +/- 0.2% (i.e.) 0.002 p.u.

When you apply 380kV to the primary of a 380kV/115V VT, the secondary voltage in the VT could be anywhere between 114.77 V to 115.23V.