Technique for independent ground fault detection of multiple twisted pair telephone lines connected to a common electrical power source

A method of delivering power, applied from an electrical power source to a span power bus, by way of a plurality of telecommunication wireline segments to respective ones of a plurality of remote telecommunication terminals, said method comprising the steps of:

• (a) coupling first portions of said plurality of telecommunication wireline segments to said span power bus, so that power is coupled from said span power bus to said first portions of said plurality of telecommunication wireline segments;
• (b) coupling second portions of said plurality of telecommunication wireline segments to said respective ones of said plurality of remote telecommunication terminals, so that power coupled from said span power bus to said first portions of said plurality of telecommunication wireline segments is delivered by said second portions of said plurality of telecommunication wireline segments to said respective ones of said plurality of remote telecommunication terminals;
• (c) coupling the first and second portions of respective ones of said plurality of telecommunication wireline segments to respective ones of a plurality of ground fault detection and isolation circuits;
• (d) causing each ground fault detection and isolation circuit to monitor the respective telecommunication wireline segment to which said each ground fault detection and isolation circuit is coupled for the occurrence of a ground fault;
• and
• (e) in response to a respective ground fault detection and isolation circuit detecting the occurrence of a ground fault on said respective telecommunication wireline segment in step (d), causing said respective ground fault detection and isolation circuit to perform the operation of decoupling, and thereby isolating, said respective telecommunication wireline segment from said span power bus, said operation being effective to prevent a change in the power being delivered by others of said plurality of telecommunication wireline segments to remote telecommunication terminals coupled thereto, and thereby prevent misoperation of said remote telecommunication terminals coupled to said others of said plurality of telecommunication wireline segments.

A system for controlling delivery of span power supplied by a span power bus to respective ones of a plurality of remote telecommunication terminals, said system comprising:

• a plurality of telecommunication wireline segments coupled to said span power bus, so that span power is coupled from said span power bus to said plurality of telecommunication wireline segments, respective ones of said plurality of telecommunication wireline segments being coupled to respective ones of said plurality of remote telecommunication terminals, so that said span power is delivered by said plurality of telecommunication wireline segments to said respective ones of said plurality of remote telecommunication terminals;
• and
• a plurality of ground fault detection and isolation circuits, coupled with respective ones of said plurality of telecommunication wireline segments between said span power bus and said plurality of remote telecommunication terminals, and being operative to monitor respective ones of said plurality of telecommunication wireline segments for the occurrence of a ground fault therein, a ground fault being capable of presenting a hazardous voltage condition to service personnel, causing electrical current in excess of normal load current to flow in a remote telecommunication terminal that is connected to the respective telecommunication wireline segment in which the ground fault has occurred, as well as producing a reduction of normal span power supplied by said span power bus and said telecommunication wireline segments, causing remote telecommunication terminals to malfunction;
• and wherein
• a respective ground fault detection and isolation circuit is operative, in response to detecting the occurrence of a ground fault in an associated telecommunication wireline segment to which said respective ground fault detection and isolation circuit is coupled, to decouple and isolate said associated telecommunication wireline segment from said span power bus, so as to prevent said reduction in said span power being delivered by others of said plurality of telecommunication wireline segments, in which no ground fault has been detected as having occurred, to remote telecommunication terminals coupled thereto, thereby preventing misoperation of said remote telecommunication terminals coupled to said others of said plurality of telecommunication wireline segments.