Resolving Transmission Line Switching Problems with ES-1

Every day across North America linemen are installing, operating and maintaining one way, two way and three way phase over phase transmission line switches. These are used to isolate and segment the system requiring switches that can break loop current and drop lines. These workers are on the front lines of the power grid, many expressing concerns with current transmission switch offerings that are often unreliable, difficult to adjust and install, require excessive maintenance and result in greater outage times for the utilities.

Southern States recognized this void in the market, specifically we understand that utilities wanted a faster and easier product assembly and installation, a device that was not dependent on operational speed and one with a long lasting contact geometry which helps maintain adjustment throughout the life of the switch. At Southern States we listen to the market to provide solutions, not just products. This approach is highlighted in our development of the ES-1 pole mounted transmission line switch backed by Southern States’ 100+ year of experience.


The ES-1 has 3 unique innovative design features: a patented collapsible frame assembly, a rigid, non-rotational blade, and a forgiving, innovative contact design. In addition, the ES-1 can be equipped with the Southern States LLS - load and line switcher: a single gap SF6 puffer interrupter that can offer the added benefit of full load breaking capability. This also comes with a health and safety indicating gauge that is not present in competing vacuum interrupting devices. The ES-1 offers all of the traditional side break switch configurations, allowing it to adapt to any mounting configuration. These include:

  • one way switches - used for basic sectionalizing, breaking long lines into smaller ones, and automatic restoration)

  • two way switches - used for circuit control at through line tap and tie points,

  • and three way switches - used for circuit control, but allowing the tap to be isolated without breaking the through line.

Why a build it Collapsible?

Shipped fully assembled and collapsed from our factory, the ES-1 patented switch design will significantly reduce installation times, saving customer time and money. Traditional offerings often require inefficient shipping procedures as well as costly assembly. The ES-1 patented collapsible frame design allows Southern States professionals set up each unit at the factory, prior to shipment, folding the unit into a compact package which can be easily received, unfolded and installed by crews. This can cut overall installation times in half.

What speed? Any Speed!

Additionally the Southern States ES-1’s rigid, non-rotational blade and contact geometry allows for trouble free seating in the jaw, regardless of operational pressure. Different manufacturers require various operating speeds, as some blades must be slammed into the jaw, while others need to be operated under a slow, continuous motion. This often creates uncertainty for linemen in the field. The ES-1’s unique design allows for either method of closure, minimizing the possibility for operator error and equipment damage.


Why the oversized contacts?

Lastly the ES-1 utilizes blade contacts and female jaw fingers replicated from a proved quality product line at Southern States. The jaw contact fingers positioned on the side use an oversized contact bar to allow for generous alignment as well as long term reliability. This design allows for improved performance during adverse weather conditions, ice loading, galloping lines, as well as normal wear and tear. Eliminating the need for precise initial adjustments and reducing the frequency of long-term field adjustments.


In summary the ES-1 solves current transmission line switching limitations by offering a fully assembled, collapsible frame that can significantly reduce installation time, a rigid, non-rotating blade that will seat properly in the jaw, regardless of closing pressure from the operator, and contact alignment that is reliable and long lasting. These features set the Southern States ES-1 apart from the competition, providing greater quality, efficiency and durability to your transmission line network.

Contact us for more information, demo, pricing and delivery times: