Electrical

The Three-Phase Automatic TTR is designed to measure the turns ratio of power, instrument, and distribution transformers in a substation or manufacturing environment. A rugged and robust design makes this TTR well suited for use in a variety of harsh environments. The TTR is also particularly suited for testing in power transformer manufacturing environments where testing of complex, three-phase substation power transformers can be performed quickly while minimizing the possibility of errors.

The Megger 550503 measures a wide turns ratio range (10,000:1) while also providing high accuracy (0.1%). The operator is able to enter the ratio of the transformer and all of its taps which indicates immediately when a tap is outside the acceptable limits. This also allows for a pass/fail limit so problem taps can be easily flagged. For single person testing a remote control switch allows the operator to test transformers with LTCs very quickly. To improve set up times and remove the need for additional test equipment the unit records ratio errors for bushing CTs to an accuracy of ±0.1% nameplate. A Quick Test Mode is also available that provides a fast determination of the turns ratio for single and three-phase transformers.

Phase deviation of the transformer primary versus secondary can be measured to indicate problems such as partial shorted turns and core faults. This measurement is also useful in verifying phase errors in all types of PTs and CTs. The Megger 550503 displays all values for each test including measured and calculated ratio, exciting current, ratio error, and phase angle deviation thus providing comprehensive and conclusive data along with automatically self-calibrating for each test.