Based on the installation method of the load switch, ring main units can be classified into side-mounted types and front-mounted types.

The side-mount ring main unit consists of electrical components, the cabinet body, and a specialized interlocking mechanism.

Primary electrical components include: FN12-12 load switches with side-mounted operating mechanisms; ISARC-type load switches; LBS- or VLBS-type load switches; current transformers; voltage transformers; and high-voltage live-line indicators. All components are securely mounted onto the cabinet body.

The cabinet body adopts a fully assembled structure, comprising a frame, top panel, door panel, and side enclosure panels. The frame and panels are all fabricated from precision-bent steel plates.

• 1When the load switch is closed, the earthing switch cannot be closed and the front door panel cannot be opened.
• 2When the load switch is open, the earthing switch may be closed. When the earthing switch is closed, the front door panel may be opened.
• 3When the earthing switch is closed, the load switch cannot be closed, but the front door panel may be opened.
• 4When the earthing switch is open, the load switch may be opened or closed, but the front door panel cannot be opened.
• 5In cable-inlet cabinets, an electromagnetic lock prevents the front door from being opened if voltage is present at the incoming cable.

Includes the FN12-12 type load switch without side-mounted operating mechanisms, ISARC type load switches, LBS or VLS type load switches, current/voltage transformers, and high-voltage live-line indicators.

Features a fully assembled structure comprising a frame, top plate, door panels, side enclosure panels, and an integrated operating mechanism.

Busbars may be manufactured from copper or aluminum.