Dry-Type Outdoor Terminations Emerge

Dry-Type Outdoor Terminations Emerge

This piece was originally published in the January/February 2019 issue of electroindustry.

Ivan Jovanovic, Managing Director, Cable Accessories, G&W Electric Company

For decades, oil-filled terminations have been the norm for high-voltage cables. Moving away from this traditional technology are pre-molded dry-type outdoor terminations.

In 2018, 138 kV pre-molded dry-type outdoor terminations were installed in three different regions of the world for the first time: Malaysia, the Philippines, and Ansonia, Connecticut; each applied mechanical shrink installation technology to new and existing grids.

To meet the growing demand for regional grid efficiency and modernization, the 138 kV termination brings several benefits. It is the first termination installed at this voltage level utilizing a mechanical shrink installation method. The 138 kV dry-type outdoor termination is a single-piece pre-molded rubber body with a built-in stress control electrode. To provide protection from harsh weather, the termination has weather sheds that lock out environmental elements.

The rubber construction offers significant benefits. Dry-type terminations are 20 to 30 percent lighter, allowing for easier installation. They are fully tested and pre-expanded in the factory, making for straightforward installation in the field and reducing the potential for field damage and installation errors. No longer containing oil, these terminations avoid field damage from any potential leak that requires maintenance and can lead to power outages.

With fewer parts to install, no installation tools required, and the weight reduced, this product significantly reduces the risk of field damage, installation time, and dependency on jointers, all while improving overall grid efficiency. The lightweight and flexible design allows for vertical, horizontal, and angled mounting positions. Installing oil-filled equipment typically requires heavy-duty machinery, which drives up labor costs and limits installation options because of proximity to energized overhead lines.

Installing pre-molded dry-type is in greater demand where new grids are being developed and the level of electrification is low, as in some developing countries where it is an easier and cost-effective option.

While the transition in the U.S. might be slower, the installation in Ansonia may be the beginning for American utilities to start moving toward dry-type single-piece pre-molded outdoor termination with a mechanical shrink installation method to improve grid efficiency.

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