The Megger MTO250 Transformer Ohmmeter stands out as a robust, field-portable solution for testing winding resistance in transformers up to 1000 MVA, shunt reactors, motors, and control circuits. With a powerful 50 A DC output, it measures resistances from 10 µΩ to 2000 Ω at ±0.25% accuracy, slashing test times for high-current windings. Its dual-channel design enables simultaneous testing of primary and secondary windings, cutting test duration significantly.
A key feature, the integrated demagnetization function, prevents core magnetization, avoiding erroneous AC test results or relay trips. The MTO250 excels in validating load tap changer (LTC) make-break transitions, detecting issues like pitting or misalignment by monitoring continuity in high resolution. Safety is paramount, with auto-discharge on power loss or lead disconnection, a safety interlock, and an optional HV strobe for hazard alerts. It stores up to 891 results across 9 groups, transferable via Ethernet, with PowerDB Lite software streamlining heat run tests and reporting. Weighing 13.6 kg, it includes 18 m universal Kelvin lead sets with 4-inch jaws and a backpack bag, supporting tests on 500 kV transformers. Operating from -10°C to 50°C, optional accessories like a remote tap controller and 30 m leads enhance flexibility. For engineers, the MTO250 ensures transformer reliability, pinpoints defects, and safeguards critical infrastructure against failures.
