Partially shorted windings on current transformers can cause them to consume too much power and overheat. If this isn’t detected, it can eventually fail after awhile. Current transformers should be tested regularly to prevent unexpected delays and injury to personnel.
Getting the right test equipment is very important to get accurate readings. A commonly used CT tester of electricians and engineers is the Megger CTER-91. This tester allows you to run excitation, ratio and polarity tests. It also lets you test current transformers while it is attached to transformers, switchgears and circuit breakers. This eliminates removing CTs from switchgears or bushings making testing convenient. It has a variable output voltage output of 0-1000 volts which allows you to test any current transformer you’ll encounter. It has two modes for reading the results of the test. The “Hold Mode” lets you freeze the recent readings of the AC ammeter, primary and secondary AC voltmeters while the “Run Mode” shows the real-time readings.
If you are interested with the Megger CTER-91 CT tester and want to evaluate it, consider renting one from Protec. You can also choose from a wide selection of Megger test equipment and other high voltage test equipment from leading brands. Contact us to learn more about rental offers.