URD Probe
Determine the Energized Status of URD Cable
There are millions of miles of Underground Residential Distribution (URD) cable buried throughout the world. Until now, there was no way to determine if this cable is energized or not. A current probe around the outside of the cable cannot be used because outgoing center conductor current is canceled out by the equal-magnitude opposite-direction concentric neutral current. An electric field probe outside the cable cannot be used either because the URD cable semicon completely shields the center conductor voltage.New Technology
The new URD Probe by the Origo Corporation solves this problem and now allows utilities to determine if a URD cable is hot or de-energized before spiking or cutting into it. The URD Probe can also be used in conjunction with the Origo PhaseID System G3 Field Probe to determine the phase attribute of URD cable.
Principal of Operation
The URD Probe is a precision instrument that is gripped with a hot stick and allows a lineman to precisely probe the URD cable to a predetermined depth using a fine needle. As soon as the needle penetrates the outer semicon shield, the needle capacitively couples to the center conductor to determine the energized status of the cable. The needle does not penetrate through the primary insulation surrounding the center conductor but only the outer semicon which shields the center conductor electric field. The lineman places the URD Probe over the cable to be tested and slowly applies downward pressure on the hot stick. As pressure increases, a fine needle begins to protrude from the probe into the cable. The cable penetration depth in mils (1/1000 inch) is precisely monitored on the probe LCD display. A mechanical penetration hard stop, based on the cable type, is set prior to probing the cable to prevent over-penetration into the cable.
When the needle touches the grounded semicon shield, a yellow (short) light may illuminate indicating that the remaining needle penetration depth required to penetrate the semicon is on the order of 50 mils. As soon as the semicon is penetrated, the yellow (short) light extinguishes and the red (hot) light illuminates if the cable is energized.
If the cable is energized, the LCD display toggles between the needle depth and a coupled voltage magnitude number which is related to the center conductor voltage and the needle distance from the conductor. The URD Probe also provides an output monitor jack that allows the cable phase attribute to be determined using the Origo PhaseID System G3 Field Probe.
Connect the monitor output jack to the G3 Field Probe wand connector input.
URD Probe Brochure
URD Probe White Paper
OPERATING THE URD PROBE
This video contains an overview of how the Origo URD Probe operates and is used.