Exciter Transformers is designed to step up the mains voltage and supply the real power required by the test system. An exciter also provides galvanic isolation and electrostatic shielding of the high voltage test circuit from the mains. The exciter is either installed in the HV reactor tank or housed in separate grounded steel, oil filled tank with output termination. It is designed as an isolation transformer with an electrostatic shield for additional filtering of PD noise and for transient protection. The exciter is fitted with an independent voltage divider for driving the exciter kilovoltmeter in the control section.