Current transformers (CT) play an important role in an electrical system, they convert the high current flowing in the main conductor to a lower and safer level for instrumentation and monitoring devices. For this reason it is important to check their accuracy. If a CT is defective, the metering devices may record wrong readings or the monitoring device like a protective relay may not trip in case of an electrical fault.
To help assess the accuracy of current transformers, the Vanguard EZCT family of Automated CT Test Sets can conduct winding, polarity, excitation and current-ratio tests. The Vanguard EZCTs also have an automated system that sets the test voltage after selecting the proper excitation test. The ratio and excitation point is automatically calculated and charted, helping to save time and effort. You can operate these test sets as stand-alone units or connect them to a computer through USB or RS232C ports. The Vanguard EZCTs also offer an onboard printer so you can print out the results after diagnostics.