Patent ID: 7586840

Claim:
An apparatus, comprising: an Ethernet switch configured to provide inline power to a plurality of ports, where members of the plurality of ports comprise a positive rail and a negative rail; a power source operatively disposed in the Ethernet switch between the positive rails and the negative rails; a floating resistance disposed between the power source and the negative rails for providing isolation from ground for the plurality of ports, the floating resistance comprising a voltage divider sensing node; ground fault circuitry operatively coupled to a voltage divider sensing node, the ground fault circuitry configured for sensing a current flowing through the floating resistance; current sensing circuitry disposed in series within the positive rails and the negative rails of the plurality of ports; find port circuitry disposed between the rails, the find port circuitry being configured to selectively couple a secondary power source in parallel with the floating resistance, thereby breaking ground isolation for the plurality of ports and increasing current flowing through the plurality of ports to facilitate detecting a fault in a member of the plurality of ports; and to detect a current mismatch between the positive rails and the negative rails of one or more members of the plurality of ports; and where the ground fault circuitry is configured to detect a ground fault in at least one of the plurality of ports of the Ethernet switch when the current detected at the voltage divider sensing node exceeds a predefined level.