The 5289 provides a motorized tuneable 15 kV, 100 kVA inductor coil to be used together with the MIDAS 2881 system and increase its test object capacitance range. Typically used on large rotating machines or other high capacitive load while testing on-site. The variable inductor is connected in parallel with the capacitive test object Cx forming a parallel resonant circuit. By adjusting the inductance the resonant point can be reached. At this resonance point the inductor compensates the reactive power required by the DUT capacitance and only the small portion of real power (ohmic losses) is needed to be fed by the Midas 2881. This arrangement enables measurement of capacitances up to 1.41 uF at 15 kV .

Applications
• Measuring power factor (capacitance and tan delta) of rotating machines on site
• Measuring partial discharges of large rotating machines on site (requires DDX9121b and 9230)