Megger MTO300 Series - The Industry's First Six Winding Transformer Ohmmeters

Megger MTO300 series transformer ohmmeters measure all six windings of a three-phase transformer automatically without changing connections. With test current capability up to 10 A, they provide simultaneous winding magnetization to ensure fast, accurate results, and auto-demagnetization after test. And, by sharing the same lead set as Megger TTR turns ratio testers, they make transformer testing even more convenient.

Selected Features and Benefits

• Automated, eight-terminal/six-winding measurement capability – saves time and money by testing all windings in one test sequence, which means big reductions in disconnect/reconnect time and “ladder time”.

• Simultaneous winding magnetization – allows MTO300 series instruments to deliver reliable results fast, even on large transformers.

• Got a Megger TTR300 turns ratio tester? – The leads are the same as the MTO300 series. Connect once to test both turns ratio and resistance.

• On-load tap-changer testing – continuous operation with graphical display of winding resistance per tap, and test current change detection.

• Auto-demagnetization feature – removes residual magnetization of the transformer core after testing, making the transformer ready for SFRA or excitation tests, or for return to service.

• Automatic discharge for safety – active circuitry monitors both current and voltage leads to ensure safe discharge of the transformer after test, even if the power is lost.

• PowerDB compatibility – store, organize and archive your test data, and produce reports quickly and easily in almost any format.

• Two models to suit all users – The MTO300 is controlled by PowerDB software on an external PC while the MTO330 has its own on-board computer, keyboard and display.