The design and structure of KYN61 type 35KV indoor metal armored high-voltage switchgear shall comply with the requirements of national standard GB3906 for indoor AC metal armored withdrawable switchgear. All metal parts of the switchgear shall have anti rust and anti-corrosion measures.

1. Reliability and safety

The outer shell of the switchgear and the partitions of each functional unit are bolted together with aluminum zinc coated plates, and each compartment is isolated from each other. Pressure release devices are installed above the handcart room, busbar room, and cable room. When an internal fault occurs in the circuit breaker room or cable room, the pressure release metal plate installed at the top will be automatically opened to release pressure and gas, ensuring the safety of the switch and operators.

2. Grounding method and requirements

a. The grounding of each component installed in the switchgear should comply with the requirements of its own technical conditions.

b. A common grounding conductor should be arranged along the width direction of the switchgear. When the conductor is made of copper, its cross-sectional area should not be less than 150mm2. If it is not made of copper, its cross-sectional area should be determined according to Appendix F of GB3906. The grounding conductor should have a terminal block for connecting to the grounding system.

c. The wiring terminal of the grounding conductor should be made of copper, and the diameter of its fixing bolt should not be less than 12mm.

d. The outer shell of the switchgear should be equipped with wiring terminals for grounding.

e. The contact surface of the grounding conductor terminal should not be less than 400mm2, and there should be a grounding symbol near the terminal.

f. The grounding conductor and grounding wire shall comply with the provisions of GB2681.

g. In addition to the main and auxiliary circuits, metal parts designated for grounding should also be connected directly or through metal components to the grounding system.

3. Quality requirements and interchangeability of main components and assemblies

Handcarts are divided into circuit breaker handcarts, voltage transformer handcarts, metering handcarts, isolation handcarts, etc. according to their purposes. The height and depth of each type of handcart are uniform, and handcarts of the same specifications can be interchanged. Handcarts have isolation positions, testing positions, and working positions inside the cabinet. Each position is equipped with a positioning device to ensure that the handcart cannot be moved freely when it is in the above position, and the interlock must be released when moving the handcart, so that the circuit breaker handcart can be opened before moving. The position reached by the handcart inside the cabinet can be indicated or locked by electrical position indicators or mechanical positioning devices.

4. During the process of moving the handcart from the isolation position and test position to the working position, the static contact partition installed on the static contact box in the busbar room and cable room automatically opens, and completely closes when moving in the opposite direction, ensuring that the operator does not touch the live body. The circuit breaker handcart can be operated with the switch cabinet door closed.

5. The design and structure of the product should meet interlocking requirements and be able to:

a. Prevent pushing and pulling circuit breaker handcart with load;

b. Prevent accidental opening and closing of circuit breakers;

c. Prevent closing the circuit breaker when the grounding switch is in the closed position;

d. Prevent accidental closing of the grounding switch when energized;

e. Prevent accidental entry into electrified compartments.