Megger LTC 135 Load Tap Changer Testing Power Supply


  • Winding resistance measurement 
  • Dynamic resistance measurement (DRM) 
  • Switch sequence timing 
  • Transition resistor measurement 

 Megger’s LTC135 is an accessory for circuit breaker analysers to test load tap changers where it delivers test currents for the measurements. The load tap changer is the only moving part connected to the transformer windings. Taking a transformer off the system to investigate an internal problem with a tap changer is an expensive exercise, therefore it is in every utility’s interest to carry out condition assessments of their tap changers, to help detect developing faults at an early stage.

The LTC135 is designed to be used with the EGIL, TM1700 and TM1800 series. With a circuit breaker analysers (CBA),  it becomes a test setup for performing dynamic measurements on load tap changers. The unit can also be used for winding resistance measurements and other applications where a constant DC current test signal is requested. It is a power supply designed for DC current testing of inductive loads with provisions for discharging the transformer winding when the test is finalised.