Universal American standard medium voltage armored switchgear

Unlike domestic medium voltage switchgear, which are all KYN28 mid mounted cabinets with the same structural layout and even size. Therefore, the supporting circuit breaker handcart, contact box, valve mechanism, mechanical interlocking, and so on are all universal components with almost no difference.

Especially for cabinet shells, most complete manufacturers do not produce cabinets themselves, but purchase from professional cabinet manufacturers according to order requirements.

The medium voltage armored switchgear produced by American standard manufacturers, except for the width dimension of 36 inches (914mm) and the basic layout of double-layer circuit breaker handcarts, have different forms of circuit breakers, handcarts, and propulsion mechanisms, each with its own characteristics. Therefore, not to mention the cabinet, even the valve and propulsion mechanism cannot be adapted to American standard circuit breakers and cannot be purchased. The existing supply chain of domestic mid mounted cabinets cannot provide supporting products.

At present, domestic complete equipment manufacturers conduct their own tests, and it is very difficult to certify medium voltage circuit breakers in North America. It is not a technical parameter issue, but a huge cost of testing and certification. In addition, the recognition of domestic circuit breakers by North American customers is not high, and after-sales service will also face huge challenges due to the lack of institutions in North America.

Therefore, choosing medium voltage circuit breakers with American standard certification, along with circuit breaker compartments equipped with contact boxes, valves, secondary plugs, grounding contacts, MOC, TOC, ASD, or L-shaped frames, can quickly meet user requirements when assembled into cabinets.

The solution to quickly solve the above problems is also simple. The switchgear adopts a side panel form, and the cabinet body can be appropriately enlarged in size. For example, the cabinet width can be 30 inches 762mm or 36 inches 914mm; the cabinet depth can be 100 inches 2540mm, because the American standard instrument room is generally installed in the front of the circuit breaker handcart, and the compartment is generally deep. The L-shaped frame includes a front extended guide rail, with a depth of about 1.25 meters. The rear cabinet needs to consider the connection between the busbar room and the upper and lower double-layer cables, which also needs to be about 1.25 meters.

The cabinet height is 95 inches 2413mm. This can accommodate an American standard 26 inch 660mm L-shaped frame and its circuit breaker.

The American standard 26 inch 660mm L-shaped frame and its circuit breakers include Eaton, LS, SCHNEIDER, etc., with a maximum current of 2000A, a circuit breaker phase spacing of 178mm, and a maximum breaking current of 40kA, which can meet general engineering needs.

The 3000A 40kA circuit breaker is assembled in loose parts or with a cabinet width of 38 inches, 38 × 25.4=965mm. The L-shaped circuit breaker frame is generally 914mm wide, with a 25.5mm side panel connection on one side.

The overall side panel structure allows for flexible matching of the front cabinet according to the height of the circuit breaker compartment. The upper and lower compartments are arranged in a double layered manner, and an instrument room can be reserved in the middle, such as an L-shaped frame with a height of 1000 meters. For a 95 inch 2413mm high switchgear, 2413-2000=413mm, and a 413mm high instrument room. For general American standard non arc switchgear, the instrument room is located in front of the circuit breaker and generally reserved with a depth of 10 inches and 254mm for microcomputer protection and other devices to ensure that the microcomputer protection and circuit breaker do not interfere with each other when the circuit breaker is in the test position.

The middle of the rear cabinet serves as a busbar room, with the main busbar height located in the center, making it easy to connect the upper and lower circuit breaker branch busbars. The copper busbar for the lower circuit breaker outlet is raised to facilitate cable connection, and a cable channel needs to be designed for the upper circuit breaker inlet and outlet