A system for an electrical power distribution network includes an electrical apparatus configured to monitor or control one or more aspects of the electrical power distribution network, the electrical apparatus including a contact switch configured to open and close. The system also includes an input apparatus. The input apparatus includes an impedance module; and an input interface electrically connected to the impedance module and to the contact switch of the electrical apparatus. The input interface is configured to have one of a plurality of input impedances, the plurality of input impedances include at least a first input impedance and a second input impedance that is lower than the first input impedance, and the input interface has the second input impedance when the contact switch of the electrical apparatus is open. The input apparatus may include a plurality of leakage current detection modules.