Ground fault monitoring system

Abstract

A ground fault monitoring system includes a ground fault interface device including a power interface and a data interface. The ground fault interface device is structured to output power via the power interface and to receive data via the data interface. The ground fault monitoring system also includes a plurality of ground fault devices structured to detect a ground fault on an associated circuit, to output data of the detected ground fault to the ground fault interface device, and to receive power to operate the ground fault devices via power lines. The plurality of ground fault devices are electrically connected in a series connection with the ground fault interface device by data lines and power lines. Each of the ground fault devices is configured to pass through received data and power.

What is claimed is: 
     
         1 . A ground fault monitoring system comprising:
 a plurality of data lines;   a plurality of power lines;   a ground fault interface device including a power interface structured to connect to one of the power lines and a data interface structured to connect to one of the data lines, wherein the ground fault interface device is structured to output power via the power interface and to receive data via the data interface; and   a plurality of ground fault devices each structured to detect a ground fault on an associated circuit, to output data of the detected ground fault to the ground fault interface device via the data lines, and to receive power to operate the ground fault devices via the power lines,   wherein the plurality of ground fault devices are electrically connected in a series connection with the ground fault interface device by the plurality of data lines and the plurality of power lines,   wherein each of the plurality of ground fault devices is configured to pass through data received via the data lines to a previous one of the plurality of ground fault devices in the series connection if the ground fault device is not first in the series connection and to pass through data received via the data lines to the ground fault interface device if the ground fault device is first in the series connection, and   wherein each of the plurality of ground fault devices is configured to pass through power received via the power lines to a next one of the plurality of ground fault devices in the series connection.   
     
     
         2 . The ground fault monitoring system of  claim 1 , wherein each of the ground fault devices includes:
 a data input interface structured to connect to one of the data lines and to receive data;   a data output interface structured to connect to one of the data lines and to output data;   a power input interface structured to connect to one of the power lines and to receive power; and   a power output interface structured to connect to one of the power lines and to output power,   wherein the ground fault device is configured to pass through data received at the data input interface and to output said data at the data output interface, and   wherein the ground fault device is configured to pass through power received at the power input interface and to output said power at the power output interface.   
     
     
         3 . The ground fault monitoring system of  claim 1 , further comprising:
 a plurality of current sensors,   wherein each of the ground fault devices is electrically connected to a corresponding two of the current sensors, and   wherein the ground fault devices are structured to detect ground faults on the associated circuits based on outputs of the current sensors.   
     
     
         4 . The ground fault monitoring system of  claim 1 , wherein the data of the detected ground fault includes a ground fault current level on the associated circuit. 
     
     
         5 . The ground fault monitoring system of  claim 1 , wherein each of the ground fault devices includes a trip output interface; and wherein each of the ground fault devices is configured to output a trip signal to an associated circuit breaker via the trip output interface. 
     
     
         6 . The ground fault monitoring system of  claim 5 , wherein the ground fault interface device is structured to control the ground fault devices to output the trip signal. 
     
     
         7 . The ground fault monitoring system of  claim 5 , wherein the ground fault devices are each configured to output the trip signal when a detected ground fault current on the associated circuit exceeds a predetermined value. 
     
     
         8 . The ground fault monitoring system of  claim 1 , wherein the ground fault interface device includes a display structured to display data received from the ground fault devices. 
     
     
         9 . The ground fault monitoring system of  claim 1 , wherein the plurality of ground fault devices includes at least three ground fault devices. 
     
     
         10 . A ground fault monitoring system comprising:
 a plurality of power lines;   a ground fault interface device including a power interface structured to connect to one of the power lines and a wireless receiver structured to receive wirelessly transmitted data, wherein the ground fault interface device is structured to output power via the power interface; and   a plurality of ground fault devices structured to detect a ground fault on an associated circuit and to receive power to operate the ground fault devices via the power lines,   wherein each of the plurality of ground fault devices includes a wireless transmitter structured to output the data of the detected ground fault to the wireless transmitter included in the ground fault interface device,   wherein the plurality of ground fault devices are electrically connected in a series connection with the ground fault interface device by the plurality of power lines, and   wherein each of the plurality of ground fault devices is configured to pass through power received via the power lines to a next one of the plurality of ground fault devices in the series connection.   
     
     
         11 . The ground fault monitoring system of  claim 10 , wherein each of the ground fault devices includes:
 a power input interface structured to connect to one of the power lines and to receive power; and   a power output interface structured to connect to one of the power lines and to output power,   wherein the ground fault device is configured to pass through power received at the power input interface and to output said power at the power output interface.   
     
     
         12 . The ground fault monitoring system of  claim 10 , further comprising:
 a plurality of current sensors,   wherein each of the ground fault devices is electrically connected to a corresponding two of the current sensors, and   wherein the ground fault devices are structured to detect ground faults on the associated circuits based on outputs of the current sensors.   
     
     
         13 . The ground fault monitoring system of  claim 10 , wherein the data of the detected ground fault includes a ground fault current level on the associated circuit. 
     
     
         14 . The ground fault monitoring system of  claim 10 , wherein the ground fault interface device includes a display structured to display data received from the ground fault devices. 
     
     
         15 . The ground fault monitoring system of  claim 10 , wherein each of the ground fault devices includes a trip output interface; and wherein each of the ground fault devices is configured to output a trip signal to an associated circuit breaker via the trip output interface. 
     
     
         16 . The ground fault monitoring system of  claim 10 , wherein the plurality of ground fault devices includes at least three ground fault devices. 
     
     
         17 . A ground fault monitoring system comprising:
 a ground fault interface device including a wireless receiver structured to receive wirelessly transmitted data; and   a plurality of ground fault devices structured to detect a ground fault on an associated circuit,   wherein each of the plurality of ground fault devices includes a wireless transmitter structured to output the data of the detected ground fault to the wireless transmitter included in the ground fault interface device,   wherein each of the plurality of ground fault devices includes a power input interface structured to electrically connect to and receive power from a corresponding power source, and   wherein each of the plurality of ground fault devices is structured to use power received via the power interface to operate the ground fault device.   
     
     
         18 . The ground fault monitoring system of  claim 17 , further comprising:
 a plurality of current sensors,   wherein each of the ground fault devices is electrically connected to a corresponding two of the current sensors, and   wherein the ground fault devices are structured to detect ground faults on the associated circuits based on outputs of the current sensors.   
     
     
         19 . The ground fault monitoring system of  claim 17 , wherein the data of the detected ground fault includes a ground fault current level on the associated circuit. 
     
     
         20 . The ground fault monitoring system of  claim 17 , wherein the ground fault interface device includes a display structured to display data received from the ground fault devices. 
     
     
         21 . The ground fault monitoring system of  claim 17 , wherein each of the ground fault devices includes a trip output interface; and wherein each of the ground fault devices is configured to output a trip signal to an associated circuit breaker via the trip output interface. 
     
     
         22 . The ground fault monitoring system of  claim 17 , wherein the plurality of ground fault devices includes at least three ground fault devices.