The electric utility industry has evolved from horse and buggy, wooden ladders and temporary platforms to hot line tools, boom trucks and material handling buckets. Many of the live-line working tools used for electrical equipment maintenance while the equipment is energized were developed in the first part of the 20th century. As the electric utility industry continues to evolve, so do the tools used to make the work more cost effective, efficient and safe.
One of the main design goals of an overhead power line is to maintain adequate clearance between energized conductors and the ground so there isn't contact with the line. Another is to provide support to the conductors, which permit the flow of electric charges in one or more directions, from potential causes of damage during storms or ice on the lines. On the transmission side of the business, these tools and techniques used to hold conductors often do not have the load rating needed to handle these transmission conductors. In addition, traditional live line tools require much rigging and are not intended to be installed for long time periods or in wet weather conditions.
Georgia Power's Alan Holloman, a maintenance and support team leader, developed a way to find a more efficient solution to handle these transmission conductors. Holloman developed the Hot Line Base Plate to facilitate construction, restoration and maintenance on energized transmission lines.
The base plate allows a transmission crew to install a non-ceramic insulator on a tubular steel, concrete or wood pole without the need of boring holes or banding to temporarily hold a conductor in place during emergency repairs. The base plate also has an attachment to create a brace post configuration for heavy load conditions. The use of the base plate will allow a utility crew to get a line in service faster during abnormal conditions, which increases system security and customer satisfaction. In many cases, the line can be temporarily put back in service with the use of the base plate, and the final repair can be performed at a later time, energized or de-energized.
The base plate is also rated to hold energized conductors as part of the live-line working program. Because the base plate is rated mechanically to hold a post non-ceramic insulator (NCI), the NCI should be rated for the voltage to be installed to obtain the proper insulating properties required. In some cases, to increase safe working space-known as minimum approach distance (MAD)-for live line activities, the use of a higher class NCI that is longer can be implemented.
|Traditional methods to perform live line maintenance.|
Using the base plate with a post NCI along with a material-handling aerial device or line truck with a rated insulated link stick can reduce a live-line maintenance procedure by as much as 50 percent while increasing safety. That procedure has been known to take up to eight hours-based on field use-using traditional live-line tool rigging.
The base plate is also useful when the need for a short temporary two-pole or three-pole line re-route is required. Many times, this type of job can use different kinds of poles because of the temporary nature, which the base plate with NCIs is useful for. In many cases, these temporary projects require live line work in the final stages of the project where the mobility of the base plate and NCIs are helpful.
|The safe and more efficient way to perform live line maintenance on energized 115 kV arm replacement using the Hot Line Base Plate, NCI post insulators and insulated aerial device.|
Because the base plate can be installed without boring a hole or banding the pole, the Georgia Power transmission crews have experienced the benefits this patented solution has provided-such as a reduction in outage time when replacing failed arms or post insulators, overall reduced cost and enhanced process.
The Hot Line Base Plate has been patented with the United States Patent and Trademark Office and is now available commercially.
If you would like more information about the Hotline Base Plate, please contact Barry Baker with Connector Manufacturing Corp. (CMC) at 404-312-7615.
Circle 104 on reader service card