Shared equipment allows fast, economical diagnosis of underground faults
Since 1972 Guthrie County REC and five other local electric cooperatives (Clarke Electric Cooperative, Southwest Iowa REC, Famers Electric Cooperative, Midland Power Cooperative, and Pella Cooperative Electric) have jointly owned a van outfitted with underground locating equipment. During an underground outage situation, co-op workers quickly can diagnosis the problem, allowing them to restore power to members in as short a timeframe as possible.
Once the crew isolates the area of the fault, they take measurements to be sure the sections in front and behind the area are not energized, so they can safely continue with the diagnosis. Then they run a cable connected to 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; they hear a thumping sound when the fault is discovered. The 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.