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MTO250 Transformer Ohmmeter 50 A

Megger MTO250 Transformer Ohmmeter designed to measure the resistance of all types of magnetic windings safely & accurately.

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13506.00 incl. VAT)
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Megger MTO250 Transformer Ohmmeter - Line-Operated / Field- Portable

Megger MTO250 has been designed specifically to measure the resistance of all types of magnetic windings safely and accurately.  The dual set of potential inputs enables the resistance measurement of either two primary, two secondary windings, or of a primary plus a secondary winding simultaneously. This dual reading, dual injection characteristic, is a highly efficient method of completing tests in a timely manner.


Megger MTO250 Key Features:

  • Testing capability:
    • transformers
    • shunt reactors
    • rotating machine windings
    • performs low resistance measurements on connections, contacts and control circuits
  • 50 amp test current reduces test time on high current secondary windings by up to 10 times when compared to traditional 10A units
  • Internal data storage with nine internal sets (groups) of results, allowing for easier organization while in the field
  • Two channel digital displays allows for testing two windings at a time, improving traditional test time by 50% or more
  • Computer-aided test form guides operator through connections and tests for all single- and three-phase transformers via PC control or data download
  • Checks the contact and timing health of on-load tap changers
  • Patented universal kelvin clamps, with 4 inch (100 mm) adjustable jaws are available, eliminating the need for multiple types of lead clips (each kelvin clamp also includes banana plugs for use of external probes for testing on terminal blocks)
  • Built-in safety discharge circuit safely discharges the specimen when test is completed, if lead accidentally disconnects, or if power is lost
  • Automated ‘heat run‘ testing and report via PowerDB software


Megger MTO250 Applications:

  • Perform field testing of CT, PT, power transformer windings and their associated tap changers, and motors/generators.
  • Verify factory winding resistance test results.
  • Perform factory heat run tests.
  • Diagnose and pinpoint problems such as the presence of defects in transformers, such as loose connections, and poor tap changer
  • To validate proper “make-before-break” operation of  load tap-changers (LTC).


Comparison Chart for: Megger MTO250 Transformer Ohmmeter 50 A

Maximum windings connected22266
Max DC test current in A610501010
Direct digital read out
PC Control
PC on-board