For many years, stakeless or clamp-on testing has been accepted as an established method of testing earth system resistance, and is now included in the German standard VDE 0100-600:2008 (appendix B3). This method has a number of real user benefits, in particular not having to disconnect the electrode under test, increased user safety and huge savings in time and aggravation. However, many users are failing to enjoy the benefits of stake-less testing, and that’s mainly down to two main issues. Firstly many potential users do not fully understand the testing technique, and avoid it; secondly many people have found some problems when testing, resulting in a number of concerns.
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 MTO3xx 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.