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Live Wire Operation
The Live Wire tool consists of a short hotstick tube, an instrument box, and a 6" stainless steel barrel with a spring loaded center probe. The tool is attached to an appropriate length hotstick and pressed against the URD cable. On unjacketed cables, the spring loaded tip must touch the semiconductor between adjacent concentric neutral wires while the barrel touches the wires.
On jacketed cables, a heater adapter is attached to the Live Wire barrel and heated with a torch until the heater reaches 200 degrees centigrade as indicated by the supplied thermometer. The heater adapter barrel contains a thin lip and a small center tip which melts through the outer jacket and contacts the internal ground conductors and semiconductor. The concentric neutral wires prevent the heater from penetrating through the semiconductor. Soft jacket material reflows back into the penetrations when the heater is removed, leaving only very small impressions in the jacket.
When viewing the Live Wire tool at the end of the hot stick, a pattern of 6 lights is observed. The label illustrated is attached to the tool and indicates the energized condition of the cable. All lights are yellow except the DEAD light which is green and the LIVE light which is red.
The tool automatically turns itself on when applied correctly to the URD cable. This ON state is indicated by illuminating the center lamp on the top row.
If both the tip and the barrel touch a concentric neutral wire, a SHORT condition occurs which is indicated by illuminating the left lamp on the top row.
If a good connection is not obtained to both the semiconductor and a concentric neutral wire, an OPEN condition is indicated by illuminating the right lamp on the top row.
A good connection is indicated when both the SHORT and OPEN lamps are extinguished. Only then is the small voltage between the semiconductor and the concentric neutral wire measured. If no voltage is present, the bottom row left green DEAD lamp is illuminated which indicates the cable is not energized. If a voltage is present, the bottom row right red LIVE lamp is illuminated which indicates the cable is energized.
If a good connection is established to the cable, but the energized state of the cable cannot be determined, the bottom row center UNKNOWN lamp is illuminated.
Patent Pending
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