Transformer Ohmmeter measures winding resistance

For smaller distribution and transmission transformers, the MTO106 is a transformer Ohmeter to measure winding resistance. It is compact and portable, weighing just 7.25kg (16 pounds).

To operate the MTO106, the user makes the ground connection, connects the power and then make connections to the transformer under test using the supplied Kelvin leads. Once the required test current is selected, the user simply presses the start button. Test results are clearly shown on a large backlit display.

To ensure safe operation, both audible and visual indicators alert users that a test is being conducted. At the end of the test, the winding is automatically discharged with visual and audible indicators alerts. Discharge continues until completion, even if the supply to the instrument is turned off.

The MTO106 has two test channels and manually selectable test currents in five steps up to a maximum of 6.0A. This allows the current to be chosen correctly for the transformer under test, while minimising the risk of heating the windings. The Ohmmeter delivers an open circuit test voltage up to 48V, ensuring that even large transformers are saturated rapidly, reducing the time needed for testing.

The MTO106 can detect problems like faulty tap changer contacts, broken conductors, shorted winding disks or layers, as well as poor bushing connections.  This tester can also be used to measure the winding resistance of other inductive assets, including generators and motors.

The MTO106 carries out winding resistance measurements in line with most major transformer testing standards, including those set by CIGRE, IEEE, IEC and ANSI.

Megger manufactures and supplies test and measurement equipment used in telecommunications, building wiring and the electric power industries.

It has research, engineering and manufacturing facilities in the USA, UK, Sweden and Germany, combined with sales and technical support in most countries.

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