CT-PT Auto Test

A Systematic way to increase the efficiency, productivity of the CT/PT testing department.

CPAT is a fully integrated test suite for testing of Current Transformer & Potential Transformer for all rating. The suite consists of

Test bench

CPAT Pro software

measuring instruments


Loading transformer

Balancing transformer

Excitation transformer

HV tester

Standard CTs / PTs

Burden Box

Name plate Punching machine


With CPAT, operator connects test bench leads to the CT/PT under test. Then he clicks to start tests in sequence. CPAT then automatically conducts all the tests and signals completion on the screen. CPAT prints report that are in full compliance with IS, IEC standards. In CPAT, there is facility to test multiple CTs at a time.

Salient Features

• Automatic Tap & Core selection of CT under test

• Automatic Tap selection of primary & Secondary of std. CT

• Automatic burden selection

• Automatic Injector & Exciter operation

Benefits of CPAT

• Automated data acquisition ensures error free data logging

• Allows users to easily store and retrieve data with simple but intuitive graphical user interface.

• Increases testing productivity significantly by reducing test preparation time, testing process time and report generation time

• Because of fixed cabling with instruments, CPAT eliminates the subsequent cable connection time.

Following tests covered by CPAT

• Insulation Resistance

• Accuracy test

• Winding Resistance

• Over Voltage Inter Turn Voltage

• Composite Error

• Knee Point Voltage Measurement


• Instrument Safety Factor

• Power-Frequency voltage withstand test on winding

• Partial discharge

• C-Tan Delta

• Temp. rise of winding

• Voltage withstand test on secondary winding

Instruments covered in CPAT

• CT/PT Bridge

• Resistance meter

• Power Analyzer

• IR Meter