Vacuum Isolating Phase Change Switch

Vacuum technology for arc-free switching, environmental safety (no SF6 gas), and reliability in overhead or indoor applications. Combining vacuum-based isolation, load breaking, and phase reversal in a three-phase, medium-voltage setup. These are often marketed as vacuum load-break switches, reversing disconnect switches, or motor control isolators with phase-changing capabilities. 

What is a Vacuum Isolating Phase Change Switch?

A vacuum isolating phase change switch is a specialized electrical switch designed for use in three-phase AC power systems, typically operating at 50 Hz. It combines the functions of isolation, phase reversal, and limited load breaking using vacuum interrupter technology. The vacuum interrupter extinguishes electrical arcs in a vacuum environment, enabling safe disconnection and reconnection of circuits under load or fault conditions. This type of switch is particularly valued for its ability to change the phase sequence (e.g., to reverse motor direction) while providing a visible isolation gap for safety verification. It is commonly employed in industrial and utility applications where reliable isolation and phase control are critical, such as in mining, motor control, and power distribution systems.

The vacuum technology ensures minimal arcing, high breaking capacity, and a maintenance-free operation, making it superior to traditional air or oil-based switches in certain scenarios. The "isolating" aspect refers to its primary role of physically disconnecting a circuit to ensure it is de-energized for maintenance or safety, while "phase change" indicates its capability to alter the sequence of phases, often used to control the rotational direction of three-phase motors.

What is the Application of Vacuum Isolating Phase Change Switch?

Vacuum isolating phase change switches are highly versatile, finding critical applications across various industries. In underground coal mines, such as with the GLC-800/3.6 model, they serve as isolators in explosion-proof electromagnetic starters, ensuring safe operation under hazardous conditions. They are widely used for starting and reversing three-phase AC motors in manufacturing plants, as seen with the GHC79 series, and for controlling electric furnace transformers. In power distribution, models like the GHZ series provide reliable isolation in substations and overhead lines up to 6 kV. These switches also excel in harsh environments like steel plants and chemical facilities, offering robust performance for long-distance line sectionalizing and motor control, enhanced by their visible isolation gaps for safety.