Megger MTO 300 and MTO 330 Automated Transformer Ohmmeter


  • Automated 8-terminal/6-winding measurement capability 
  • Simultaneous winding magnetization 
  • Tests operation of on-load tap-changers 
  • Built-in auto-demagnetization feature 
  • Automatic discharge 
  • Power DB software (MTO330) 


The MTO 300 series delivers full eight-terminal/six-winding resistance measurement capability. It is designed to save time for the user by testing all normal 6 windings without having to disconnect and reconnect leads during testing.

The MTO300 series also shares the Megger TTR300 series lead set. Users who test both turns ratio and winding resistance can save time and money since only one lead set is needed to connect to the transformer.