Megger MTO300/330A Automated Six-Winding Transformer Ohmmeter - Optional Onboard Computer

The Megger MTO300/330A Automated Six-Winding Transformer Ohmmeter can be used to measure the resistance of transformers, even large transformers with delta configurations on the low voltage side, quickly and reliably. It delivers automated eight-terminal/ six-winding resistance measurement which significantly reduces safety risks and saves you time by testing all six windings without having to disconnect and reconnect test leads. Moreover, the Megger MTO300/330A Automated Six-Winding Transformer Ohmmeter’s ‘one clamp per designated bushing’ concept reduces the likelihood of making lead connection errors.

The Megger MTO300/330A Automated Six-Winding Transformer Ohmmeter offers a DC test current up to 10A and it includes a built-in discharge circuit that safely discharges the transformer when the test is complete, the lead accidentally disconnects, or the power is lost. Moreover, integrated demagnetisation circuitry allows the operator to de-magnetise the transformer core once resistance testing has been completed. Additionally, it can be used before SFRA testing or when the transformer is put back into service. Simultaneous winding magnetisation facilitates fast and accurate DC winding resistance measurements of high inductive loads.

Modular Testing

The Megger MTO3XX Automated Six-Winding Transformer Ohmmeters are the latest additions to Megger’s eclectic range of instruments with a common digital platform. This means the Megger MTO3XX Automated Six-Winding Transformer Ohmmeters can be linked with other compatible Megger transformer test instruments. In addition to this, they share an interchangeable lead set with the Megger TTR300 Series of 3-Phase Turns Ratio Instruments, saving you time and money.

There are two versions of Megger's MTO3XX Ohmmeters available:

• MTO300: this model does NOT include an internal PC; it can be operated using an external PC or other Megger products with an onboard computer such as the DELTA4310A and TTR330A.
• MTO330A: this version includes an industrial-grade internal computer with a 12-inch touch controller and a display that remains visible in direct sunlight. It can be used to control other Megger instruments such as the TTR300, TTR310, DELTA4310A, and MLR10. This version is also equipped with a ‘safety shutdown’ feature which saves results and shuts down the controller in the event of an abrupt power disruption.

MTO330A Onboard Software

The Megger MTO330A Automated Six-Winding Transformer Ohmmeter’s computer is powered by PowerDB software. It provides an easy-to-navigate, common user interface that minimises operator training and seamlessly interfaces with the full PowerDB (PC version) application. Results are displayed alongside PASS/FAIL assessments and can be stored on the Megger MTO330A Automated Six-Winding Transformer Ohmmeter or a USB memory stick in an open XML format. A historical data file allows current and past results to be analysed, compared, and displayed in trend charts on the Megger MTO330A while in the field. Furthermore, an integrated two-inch printer allows you to print critical results on site.

In addition to this, you can easily recall transformer setups from the PowerDB Software’s custom settings menu, while a custom PowerDB form enables production heat-run (interval) testing.

Applications

The Megger MTO300/330A Automated Six-Winding Transformer Ohmmeter can be used to:

• Verify factory test readings
• Locate the presence of defects in transformers, for instance, increased contact resistance in terminal connections and tap-changers
• Check the operation of on-load tap changers

The Megger MTO300/330A Automated Six-Winding Transformer Ohmmeter is an adaptable and efficient transformer resistance meter.

Megger MTO300/330A Automated Six-Winding Transformer Ohmmeter Key Features

• Measure the resistance of transformers quickly and reliably
• Suitable for measuring large transformers with delta configurations on the low voltage side
• Automated eight-terminal/ six-winding resistance measurement
• Test all six windings without having to connect and disconnect test leads
• Save time and improve safety
• ‘One clamp per designated bushing’ concept reduces the likelihood of making lead connection errors
• DC test current up to 10A
• Built-in discharge circuit
• Simultaneous winding magnetisation enables fast and accurate DC winding resistance measurements of high indictive loads
• Can be linked with other compatible Megger transformer test instruments
• Interchangeable lead set with Megger’s TTR300 Series of 3-Phase Turns Ratio Instruments
• MTO300: does NOT include an internal PC; it is operated using an external PC or Megger instruments with an onboard PC
• MTO330A: includes an industrial-grade internal PC with a 12” touch controller, a display that is visible in direct sunlight, and PowerDB Software
• Verify factory test readings
• Locate the presence of defects in transformers
• Check the operation of on-load tap changers
• An adaptable and efficient transformer resistance meter

What’s Included?

• Your Choice of Megger MTO300 OR MTO330A Automated Six-Winding Transformer Ohmmeter
• Universal AC Power Cord Set
• Ethernet Communication Cable
• USB to Ethernet Adapter (MTO300 Only)
• PowerDB Lite
• 5m Ground Lead
• Backpack Lead Bag
• MTO3XX User Guide on USB