•  Direct 2-channel digital reading (1 µΩ to 2000 Ω)
•  DC test current up to 10 A maximum
•  0.25% measurement accuracy
•  Integrated demagnetization feature
•  Tests operation of on-load tap-changers
•  Very fast auto safety discharge circuit

The MTO210 transformer ohmmeter is a line-operated, field-portable instrument designed specifically to measure the dc resistance of all types of magnetic windings safely and accurately. It can test transformers and rotating machine windings and perform low-current resistance measurements on connections, contacts and control circuits.

The Transformer Ohmmeter is extremely useful when testing the windings and contact resistance of tap-changers with “make-before-break” contacts and voltage regulators. This action will check for pitted or misaligned contacts as the instrument will give an indication if either condition occurs.

•  Automated 8-terminal/6-winding measurement capability
•  Simultaneous winding magnetization
•  Tests operation of on-load tap-changers
•  Built-in auto-demagnetization feature
•  Automatic discharge
•  Power DB software (MTO330)

The MTO 300 series delivers full eight-terminal/six-winding resistance measurement capability. It is designed to save time for the user by testing all normal 6 windings without having to disconnect and reconnect leads during testing.

The MTO3xx series also shares the Megger TTR300 series lead set. Users who test both turns ratio and winding resistance can save time and money since only one lead set is needed to connect to the transformer.

•   Stand-alone or remote-control operation
•   Accurately measures ratio, phase deviation and excitation current
•   Field upgradeable without compromise to calibration
•   Built-in capability for storing and downloading test results in an XML format, via RS-232, Ethernet or USB ports (depending on model)
•   Works in the presence of high interference/high voltage
•   Highest ratio measurement (45,000:1); highest accuracy (0.1%)
•   Displays % error vs. name plate with pass/fail limits

The TTR300 Series of three-phase transformer turns ratio test sets are designed to measure the turns ratio of power, instrument, and distribution transformers in a substation or manufacturing environment. A rugged and robust design makes these instruments well suited for use in a variety of harsh environments. Our leads are specially designed to provide the necessary flexibility needed in cold weather.

The TTR300 Series are ideal for use by power transformer manufacturers. Their unique testing procedures and storage capability allows an operator to set up and test difficult three-phase transformers (with multiple tap changers and bushing CTs) in a fraction of the time than it used to take with other TTRs. This test also includes a pass/fail limit of individual ratios.