Tools and Techniques for High-Tech Cable Locating

Nov. 1, 2008
Georgia Power field crews work together to locate cables and prevent damage

Cable locating can be like a game of high-tech hide and seek. Locators must electronically penetrate the ground, locate the power cable and then isolate the signal. Fortunately, over the last decade, technology, tools and training have made it easier for utilities to locate cables in a safe and efficient manner. Georgia Power (Atlanta, Georgia) is one utility that has invested in the latest technology to minimize damage to underground cable.

Before excavation can begin, contractors are required by Georgia law to call the Utility Protection Center (UPC) to identify where they will be digging and what type of work they will be performing. In the Atlanta area, Georgia Power responds to this notification requirement by sending one of its 36 cable locators to mark where buried utility lines are located. The excavator then must use care to avoid damaging these marked facilities.

Over the last five years, the technological advances have allowed Georgia Power to cover a wider service territory with the same number of cable locators. In the past, the utility only used its metro cable locators in the Atlanta area, but now those cable locators have expanded their work areas to include calls from the nearby towns of Rome and Cartersville, Georgia. Over time, Georgia Power has been able to integrate these locate employees into the metro workforce.

Tradition of Teamwork

When a cable is cut and customers are out of electricity, restoration time is vital to Georgia Power. If field crews had to rely on trial and error, rather than the latest tools and technology, they would be wasting valuable time. The utility's 36 cable locators working in the metro Atlanta area can support the 79 metro troublemen to isolate problem cables and restore power quickly and safely.

For example, an excavator recently slashed a cable and knocked out power to Georgia homeowners. A cable locator arrived on the site to investigate the cause of the damage, followed by a troubleman who came to restore the power. By working together, they quickly identified the cause of the outage. The troubleman then isolated the cut power line and got the power back up and running.

This relationship between the cable locators and the linemen is essential to the productivity of Georgia Power's field crews. The cable locators know the area as well as most of the field employees, and as a result, they are able to easily identify the path of the cable. In the case of the cut cable, the underground utility maps had not been updated. The cable locator, however, had been on-site when the crew installed the cable, so he was able to help the troubleman identify the path of the cable and trace it out so he could perform the necessary switching. Without this relationship between the field professionals, the troubleman would have needed to ride out the circuit until he identified the location of the damage. The cable locator had prior knowledge of the ongoing excavation project in the area and was able to go directly to the work site.

Top Technology

In addition to the teamwork between the troublemen and cable locators in the field, another key to Georgia Power's success is its investment in the latest technology.

Georgia Power, a Southern Co. utility serving 2.25 million customers, uses electromagnetic cable-locating equipment from vendors such as 3M Dynatel (St. Paul, Minnesota), Radiodetection (Bridgton, Massachusetts), Metrotech (Santa Clara, California) and Ditch Witch (Perry, Oklahoma). Over the last few years, this technology has changed very rapidly.

One of the latest advancements has been a shift from analog to a combination of analog and digital. In addition, most manufacturers' products are now software driven and completely digital, which offers many more features to locators out in the field. Some of the software-driven equipment features a built-in compass. This technology does not require field crews to keep the equipment oriented to the path of the cable on the display screen. Instead, it will show the path of the cable on the screen regardless of the direction in which the machine is being held, which speeds up production.

In addition, the equipment has many new filters, which help to isolate the signal on the target cable. With so many buried cables now, the field crews are not as hampered by stray signals as in the past.

A few years ago, the crews would receive multiple signals, which made it difficult to differentiate between the target signal and a bleed signal. Now it is easier to identify the signal the crews are looking for, which helps to reduce damage.

Best Practices

One of Georgia Power's top goals is preventing damage and keeping the power on for customers. To reach this goal on a daily basis, Georgia Power crews have several field-proven strategies that have helped to improve productivity.

The cable locators make it a priority to understand the machine and its readouts. If locators are tracing a power cable, they must start from the source and make sure they are on the power cable and not on another facility.

Another work practice that has improved productivity is the shift to wireless technology. New software for Georgia Power's ticket management system allows the locators to receive work orders wirelessly in their vehicles and reach the locations in a timely manner. They can then spend more time in the field and on each individual locate. In the past, they did not have that technology, and as a result, they had to spend time traveling back and forth to the office to receive work orders. Now that Georgia Power has this technology, it enables the field crews to get accurate locates each time.

Georgia Power's locators have been using wireless technology for the past six years, and the technology has increased productivity and reduced damage in the field. It also has made the locators' jobs less stressful, because they are receiving their emergency requests in a timely manner. By getting the requests in real time, they are able to respond in real time.

Georgia Power uses the company SouthernLINC Wireless (Atlanta) to provide its wireless connection. Each cable locator has a modem connected to a laptop in his or her vehicle. The modem receives a signal from SouthernLINC, which powers the data the Georgia Power server received from the call center across the state. The laptop is loaded with ticket management software provided by KorTerra Inc. (Chanhassen, Minnesota). The software is designed to allow the locator to read the data, schedule/sort his or her work, complete a work order from the vehicle and transmit the appropriate completion code back to the UPC.

The UPC, which is funded by the major utilities in Georgia, plays a key role in the success of the wireless technology. As stated earlier, when a utility plans to do an excavation within Georgia, it must call the UPC, identify the location where digging will take place and give the specifics of what will be done. That information is then relayed to every utility that has underground lines in the area. The utilities have 48 hours to respond back to the call center that they are aware of the upcoming project and have resolved any issues prior to excavation.

Before Georgia Power had wireless technology, the utility had to record the job information, fax it into the office and have it keyed in. Through the wireless technology, the enhanced communication with the call center and the investment in the latest technology, Georgia Power's cable locators now have the tools they need to protect their facilities from damage and keep the lights on for customers.

Gene Redden is a cable locating supervisor with Georgia Power. [email protected]

Jim Weldon is a distribution operations manager for Georgia Power and has responsibility for cable locating and claims. [email protected]

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