A system comprising: a first high voltage unit that is coupled via a high voltage supply cable to a second high voltage unit; a transformer that is configured to magnetically couple the high voltage supply cable to windings of a transformer; and a detection unit that is configured to monitor a windings signal developed in the windings of the transformer to detect a first high voltage unit arc formed within the first high voltage unit and to detect a second high voltage unit arc formed within the second high voltage unit.