Electrical protection systems

摘要

An electrical protection system on a power distribution side includes a control element of a series combination of a PTC device thermally coupled with a resistive device, and a relay coil coupled with relay contacts. If the relay contacts are open the only way in which they can be closed is by supplying current to the relay coil through a resistance-capacitance network. An electronic control module on a control side includes an electronic control module for monitoring a voltage present in the system, and a switch for opening a current path feeding the system upon detection of a fault condition. An indicator indicates presence of a sensed fault condition.