Innovative 'electric insulated support rod' strengthens safety for live-line work in Zhejiang

At the relocation construction site of the 10 kV Dama J296 Maqiao Lower Branch Line in Lishui, Zhejiang province, State Grid Zhejiang Electric Power has recently completed integrated live-line pole erection and removal operations.

This operation marked the first deployment of the company's self-developed "electric insulated support rod", achieving completely "zero-perception" power supply for users throughout the process. The innovation balances grid operation and maintenance safety, operational efficiency and quality improvement, and optimization of the business environment, using technological advancement to fortify the defense line of regional reliable power supply.

The 10 kV distribution network live-line pole erection and removal is classified as a Category III complex live-line operation and represents a key and challenging construction project in distribution network maintenance.

In existing conventional live-line pole erection and removal procedures, workers have to first install full-coverage insulation shielding protection on energized conductors and cables, then use lifting ropes to thread the pole through the phase-to-phase gaps of the cables to complete hoisting and fixing operations.

While this method reduces the scope of customer outages and improves power supply reliability, it still suffers from core technical shortcomings.
During pole hoisting, the pole is highly susceptible to swaying, and the pole body can easily contact the middle-phase and side-phase conductors, damaging the outer insulation shielding cover of the conductors. This can lead to insulation shielding failure, triggering major safety hazards such as line grounding and worker electrocution.

Additionally, traditional old-style support rods cannot reliably fix or precisely control the distance of middle-phase and side-phase conductors, making phase-to-phase cable spacing management difficult. The industry has long lacked specialized anti-collision and distance-control tooling, leaving a gap in the technical field.

Addressing industry-wide construction weaknesses, traditional tool deficiencies, and on-site operational risks, State Grid Zhejiang Electric Power launched a special project to tackle three core challenges in live-line pole erection and removal: conductor anti-collision, cable fixation, and phase-to-phase distance control.

The company independently developed an electric insulated support rod anti-collision device, filling the technical gap in distribution network live-line construction tooling and bridging the void in this technical domain.

The "electric insulated support rod" consists of four modules: a telescopic support rod, an anti-collision protection rod, a conductor pulling rod, and extension rods. Featuring a lightweight structure and easy assembly, it can both securely lock the two side-phase conductors and precisely control the safe insulation distance between the middle line and any phase line, fully adapting to various 10 kV line pole erection and removal construction scenarios.

On-site operator He Yeyun explained that the new electric insulated support rod relies on quick-lock clamps to fasten onto two-phase conductors. Workers can use an electric wrench to adjust the support rod length. Combined with the matching anti-collision protection rod, it can construct a stable, enclosed square-shaped working space, with phase-to-phase safety distances reaching up to 4 meters. The device firmly fixes conductor positions, completely eliminating the risks of line contact, grounding, and electrocution caused by a swaying pole. It eliminates redundant procedures such as rope pulling and manual alignment, simplifies on-site staffing requirements, and significantly reduces the difficulty of multi-party collaborative operations. This technological innovation implementation is a vivid practice of State Grid Zhejiang Electric Power's commitment to frontline operations and technology-enabled grid maintenance.

Going forward, State Grid Zhejiang Electric Power will continue to focus on the challenges of distribution network live-line operations and the pain points of industry technical gaps. The company will deepen independent R&D and technology application of tooling and equipment, continuously enrich the live-line operation technical system, fully minimize construction impacts, and solidify the grid safety barrier. Adhering to the principal that "no outage is the best service", the company will empower local enterprise production and people's livelihoods, continuously optimizing the regional power business environment.