Megger MTO250 Transformer Ohmmeter

The Megger MTO250 Transformer Ohmmeter is a line-operated, field-portable resistance tester suitable for checking transformers (up to 1000 MVA), shunt reactors, and rotating machine windings. It can be used to measure the resistance of all types of magnetic windings safely and accurately as well as conduct low resistance measurements on connections, contacts, and control circuits.

Efficiency is at the forefront of the Megger MTO250 Transformer Ohmmeter’s design. A dual set of potential inputs combined with dual-channel display enables resistance measurement of two primary, two secondary, or a primary and a secondary winding(s) simultaneously. The Megger MTO250 Transformer Ohmmeter is particularly well suited to testing the winding plus contact resistance of LTC (Load Tap Changers), as well as assessing the “make-break” transition event, allowing you to diagnose issues such as aggressive pitting, weak springs, and misalignment of contact mechanisms.

Furthermore, the Megger MTO250 Transformer Ohmmeter can deliver a DC test current up to 50A which reduces test time on high current secondary windings by up to ten times when compared to traditional 10A units. As applying DC current to highly inductive objects is potentially dangerous, the Megger MTO250 Transformer Ohmmeter also includes a variety of safety features such as:

• Auto discharge in the event of input power loss
• Automatic discharge in the event of inadvertent disconnection of a test lead
• Safety interlock which places the test into discharge when interrupted
• Optional high voltage strobe which warns personnel of a dangerous condition

Data can be stored on the Megger MTO250 Transformer Ohmmeter in nine internal sets (groups) facilitating better organisation while in the field. The Megger MTO250 Transformer Ohmmeter also offers guided test set ups and automated “heat run” testing and reporting via PowerDB Software.

The Megger MTO250 Transformer Ohmmeter is a precise, practical, and portable resistance tester.

Applications

The Megger MTO250 Transformer Ohmmeter can be used to: 

• 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 defects in transformers like loose connections and poor tap changer operation 
• Validate proper 'make-before-break' operation of load tap-changers (LTC)

Megger MTO250 Transformer Ohmmeter Key Features

• A line-operated, field-portable resistance tester
• Check transformers (up to 1000 MVA), shunt reactors, and rotating machine windings
• Measure the resistance of all types of magnetic windings safely and accurately
• Conduct low resistance measurements on connections, contacts, and control circuits
• Dual set of potential inputs
• Dual-channel display
• Measure two primary, two secondary, or a primary and secondary winding(s) simultaneously
• Test the winding plus contact resistance of LTC (Load Tap Changers)
• Assess the “make-break” transition event
• Diagnose issues such as aggressive pitting, weak springs, and misalignment of contact mechanisms
• DC test current up to 50A
• Reduces test time on high current secondary windings by up to 10x when compared to traditional 10A units
• Auto discharge in the event of input power loss
• Automatic discharge in the event of inadvertent disconnection of a test lead
• Safety interlock which places the test into discharge when interrupted
• Optional high voltage strobe which warns personnel of a dangerous condition
• Store data in nine internal sets (groups)
• Guided test setups
• Automated “heat run” testing and reporting via PowerDB Software
• A precise, practical, and portable resistance tester

What’s Included?

• Megger MTO250 Transformer Ohmmeter
• Canvas Carrying Bag
• AC Power Cord (IEC60320-C19 to US Standard)
• AC Power Cord (IEC60320-C19 to Schuko CEE 7/7)
• 15ft Ground Lead
• User Guide
• Quick Guide