Live-line working is a field of electrical engineering and alternatively known as hotline maintenance, pertains to the upkeep and servicing of electrical systems and components, frequently operating under high voltage, while they remain powered or energized. This approach, despite posing greater risks to personnel compared to methods involving powered-down equipment, is strategically employed in the electric power distribution sector. The primary aim is to circumvent the considerable inconvenience and substantial financial implications that would result from shutting down power supply to consumers for routine maintenance activities on transmission lines and other related apparatus.
The genesis of live-line working techniques dates back to the early 20th century. Over time, these techniques, along with the equipment used, have undergone significant advancements to accommodate the challenges posed by progressively higher voltage levels. Notably, in the 1960s, experimental methods were developed in laboratory settings, enabling field personnel to engage directly with high voltage lines without jeopardizing safety. These methodologies have been refined and adapted for application even at the most elevated levels of transmission voltages, ensuring the maintenance work is conducted effectively while prioritizing safety.
Generally, it is not feasible to ascertain through visual inspection alone whether electrical equipment is energized. Consequently, there are instances where it becomes essential to perform maintenance or repairs on circuits while they remain operational. Moreover, when dealing with high-voltage scenarios, direct contact with charged equipment is not a prerequisite for receiving an electric shock. This is due to the potential of an electrical arc to bridge the gap between the equipment and a tool or a part of the human body.
Furthermore, materials traditionally regarded as superior insulators, such as rubber, are not immune to electrical failure, especially under high-voltage conditions. The inherent properties of these materials, while effective under certain circumstances, may not provide sufficient protection against the intense electrical forces present in high-voltage environments. This underscores the importance of advanced safety measures and specialized equipment in handling and maintaining high-voltage electrical systems.
Live-Line working methods
Generally, there are three primary methods of live-line working, each designed to mitigate the significant risks associated with this type of work. These methods all share the common goal of preventing the flow of electrical current from live equipment through the worker.