Power outages or interruptions from dropped lines can be caused by a variety of factors. Damage from storms, ice or high winds can't be avoided, but power companies can limit equipment failures and prevent the huge cost of future drops by eliminating insulator arm damage.
After an insulator arm dropped a transmission line, John Wetig, Line Technician Supervisor and Tom Harbaugh, Line Crew Chief at Sunflower Electric Power Corp. in Great Bend, Kan., knew that they needed more than a repair–they needed a solution to a problem that could happen again and again.
The steel yoke that holds the transmission lines had, over time, damaged the end of the insulator blade. Movement of the yoke from the Kansas winds and winter ice had caused the steel to eat away at the aluminum. Eventually, the arm suffered enough damage to drop the yoke and the transmission line with it. The high-voltage transmission line dropped onto the distribution line below, taking it down as well.
Dropping both lines caused hundred's of thousand's of dollars in damage to the lines and substations. The entire town of Great Bend was without power for quite a while. The equipment damage, lost revenue and overtime paid to fix the mess was immense.
Upon inspecting the faulty insulator arm, an even bigger problem became evident. Sunflower Electric has thousands of this same insulator arm/yoke combinations, all of which have the potential to drop a transmission or distribution line. Economics prohibited replacing the entire unit, so how was the utility going to stop steel yokes from damaging aluminum insulator arms?
Sunflower Electric, through its partners at Cleaves-Bessmer-Marietti (CBM) turned to Pelco Products Inc. for a solution. The crew realized that the entire arm was not damaged, just the end. The engineering team at Pelco Products Inc. designed and built the Insulator Arm Adaptor Clamp to strengthen the arm, not replace it. The stainless steel construction is much more resistant to damage, offering a stronger and more secure power line mounting.
Instead of the costly, labor-intensive process of replacing the entire arm, the crews can simply clamp the stainless steel adaptor over the damaged aluminum blade. The threaded body (with anti-seize lubricant) is secured by two 2-3/4 inch long bolts, utilizing Belleville washers for a solid mounting system. The entire process takes less than five minutes, and can be done by one person. No special tools are required. Pelco Products has a three-minute, real-time video of the installation process on its Web site (www.pelcoinc.com).
The Insulator Arm Adaptor Clamp avoids line drops and insulator arm replacement in the same amount of time it would take to inspect the insulator blade. The damage is easily spotted and installation of the Insulator Arm Adaptor Clamp only takes minutes. A little preventive maintenance goes a long way toward avoiding dropped lines.
A down high-voltage line can create dangerous and damaging situations for people and property. A live line can start fires if it touches a tree branch or hits the ground, causing the electrical current to arc in explosions of sparks. According to the Department of Energy's Office of Electricity Transmission and Distribution, outage cost in residential areas can be costly for households with out-of-pocket costs for consumable goods and food spoilage, plus outages create customer dissatisfaction. A sudden loss of power in commercial or industrial areas can cost thousands of dollars per location involved, causing major losses of revenue and productivity.
The Insulator Arm Adaptor Clamp can save time and money, avoid damage and inconvenience, all while strengthening power line mountings. Line drops cannot be completely eliminated; storms and ice will still cause trouble, but damaged insulator inspection and maintenance can help limit the number of potential drops per year.
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