Underground Fault Locator
Shared equipment allows fast, economical diagnosis of underground faults
Since 1972, Guthrie County REC and five area electric cooperatives (Clarke Electric Cooperative, Farmers Electric Cooperative, Midland Power Cooperative, Pella Cooperative Electric and Southwest Iowa REC) have jointly owned a van outfitted with underground locating equipment. During an underground outage situation, co-op workers can quickly diagnosis the problem, allowing restoration of power to members in as short a timeframe as possible.
Once the crew isolates the area of the fault, measurements are taken to be sure the sections in front and behind the area are not energized, so they can safely continue with the diagnosis. A cable is connected from the faultfinding equipment housed in the van to the problem area of underground cable.
Next, the crew runs tests along the trenched underground cable until a pulse signal identifies the fault; a thumping sound is heard when the fault is discovered. Workers then employ radar equipment to pinpoint the exact distance of the fault from the starting point of the cable; finally, they make the measurement above ground and begin work on the repair.