Abstract: There is provided a circuit that protects the electronic tripping circuitry of a circuit breaker system from external transient high voltages and prolonged high voltage faults. The circuit preferably includes a transzorb that conducts in response to receiving a voltage signal having a magnitude greater than the breakdown voltage of the transzorb. This transzorb clamps the output voltage to its breakdown voltage. The circuit also includes a fuse that is designed to blow in response to a prolonged high voltage fault.

Abstract: A current regulator circuit for shunting excess current from a current supply utilizes two separate shunting paths, depending on the amount of excess current on the supply line. The first shunting circuit is activated when the current exceeds some minimum level established by a zener diode. The second current shunting circuit is selectively activated by a switching circuit which compares the current in the first shunting circuit to a reference voltage that is proportional to the line current. This arrangement is advantageous in that it shunts excess current without generating significant levels of heat or adversely affecting current sensing devices.

Abstract: An addressable relay module is provided for controlling a plurality of relay outputs associated with an electronic circuit breaker system using a trip unit for monitoring system functions or network parameters. The relay module is linked to a multi-drop serial communications network through which data pertaining to system functions is relayed to and from a communications microcontroller which controls the operational status of relay contacts linked thereto. The microcontroller addresses specific ones of associated relay outputs in accordance with address information contained within the network data. The addressable relay module effectively maps the plurality of relay contact outputs linked thereto to a corresponding plurality of network device parameters received through the multi-drop network.

Abstract: A circuit arrangement is used to interface a fault-powered circuit breaker trip unit to a communication network. The circuit arrangement includes a diode protected line which draws power from the trip unit, a battery acting as a backup power source and a control circuit, responsive to the trip unit, which detects a trip unit alarm condition, receives data from a circuit breaker trip unit and processes the data for subsequent use. In response to the control circuit detecting the trip unit alarm condition, a switch circuit enables the backup power source such that power is provided to the control circuit after the trip unit alarm condition is received so that the control circuit can process the received data after the power provided by the trip unit expires.