The resonating inductor is an accessory for use with the semi-automatic 12 kV extended range capacitance and dissipation factor test set, or the automated insulation power factor test set (DELTA series).
The resonating inductor is used to expand the capacitance range of these test sets and cannot be used with the standard 12 kV capacitance and dissipation factor test set. It is connected in parallel with the internal power supply of the test set. A manual tuning wheel varies the inductance to tune the parallel circuit for minimum load current.
When used with the semi-automatic 12 kV extended range capacitance and dissipation factor test set, or DELTA series, the resonating inductor will extend the short-time rating of the power supply from 200 mA to 4 A. This capacity is suitable for testing capacitance loads of up to 1 µF at 10 kV.