The FYN33 type four-position oil-immersed load switch is suitable for integrated transformers with AC frequencies of 50Hz and 60Hz and rated voltages of 10kV, 24kV, and 35kV. It is an ultra-small load switch specially designed for the specific environment where the space inside the integrated transformer is small and the load capacity requirements of the power grid are constantly increasing. It uses transformer oil as the insulation and arc-extinguishing medium, with spring energy storage and three-phase linkage. It can accurately and quickly make or break the load current. It is suitable for 10kV, 24kV, and 35kV ring-main or dual-power supply line distribution systems.

According to customer needs, the load switch can be made into a buried type or equipped with an electric operating mechanism for use in various types of transformers. The load switch adopts a ring-main T-type four-position structure, namely: ring-main power supply, power supply 1, power supply 2, and disconnection. The contact system of the switch adopts a double-contact bridge floating clamp plate type. It features low resistance, strong current-carrying capacity, and a good electromagnetic compensation effect, which greatly improves its load resistance. The static contact wiring board is fixed, making the installation and wiring of the switch more convenient and reliable. The additional auxiliary static contact makes the relative contact position between the moving and static contacts more accurate.

The load switch is installed on the side wall of the transformer oil tank. According to the power supply line switching requirements, the load switch is rotated clockwise or counterclockwise using a dedicated insulated operating lever. Each operation rotates the switch by 90° to the next position, and it can cycle through 360° of rotation. Customers can choose corrosion protection classes such as C3, C4, C5, etc., according to design requirements.