The RMO60TD can be used to measure winding resistance of individual taps of a power transformer’s tap changer. It can also be used to check whether the on-load tap changer (OLTC) switches without an interruption and for resistance measurement of inductive test objects. Voltages up to 60V can be injected enabling test durations to be as short as possible. Two independent channels enable testing of two series windings, or primary and secondary windings. The RMO60TD generates true DC ripple free current and both injection of current and discharge of energy from the inductance are automatically regulated. Up to 500 time and date stamped measurements are able to be stored within the unit.
The RMO60TD can be used to measure the winding resistance of individual taps on a power transformer’s tap changer without discharging between tests. The unit also checks whether the on-load tap changer (OLTC) performs switching without an interruption as well as analysing measurements of ripple, transition time, and visualizing DRM graphs. The RMO60TD can perform fully automatic demagnetization after a DC current test or when disconnecting a transformer from service. The RMO60TD has a very high ability to cancel electrostatic and electromagnetic interferences that exist in HV electric fields and is equipped with a thermal and overcurrent protection.
An automatic discharging circuit (independent of power supply) safely discharges the energy stored in the transformer windings at the end of the test in a very short time with an audible and visible indication of the discharging state provided. An automatic connections check is performed at the beginning of each test and the instrument warns the user if an open connection is detected. The companion DV-Win software enables control and observation of the test process, as well as saving and analysing the results on a PC. It provides a test report arranged in a selectable form as an Excel spreadsheet, PDF, Word, or ASCII format. The software provides an OLTC (tap changer) condition assessment through analysis of the graphs representing dynamic resistance values during the tap changer transitions.
Features
- On-load tap changer dynamic resistance measurement
- Three resistance measurement channels
- One temperature measurement channel
- Automatic resistance measurement
- Heat Run test
- Rapid automatic demagnetization
- Tap changer motor current monitoring channel
- Automatic discharge circuit
- Built-in tap changer control unit
