Detailed mechanism of high voltage switch cabinet

The switchgear is composed of a fixed cabinet and a withdrawable part (handcart). The cabinet shell and the partitions of each functional unit are bolted with aluminum-zinc steel plate. The enclosure protection level reaches IP4X, and the protection level of each compartment is IP2X.

This switchgear is generally arranged in a single row and not installed against the wall. Since the installation, debugging and maintenance can be carried out on the front of the cabinet, it can also be back-to-back to form a double arrangement or be installed against the wall.

1. Shell and partition:

The outer shell of the product is made of aluminum-zinc-coated steel plate, processed by CNC machine tools, and assembled with bolts after multiple compound folding processes. It not only has strong corrosion and oxidation resistance, but also has high mechanical strength and structural dimensions The uniformity of the product effectively ensures the neatness and beauty of the product. The cabinet door is spray-coated, which has strong impact resistance and corrosion resistance. The switchgear is divided into the handcart room, the busbar room, the cable room and the relay instrument room by the partition, and each unit is independently grounded.

2. Handcart:

The insulation coordination and mechanism interlocking between the handcart and the cabinet are safe, reliable and flexible. According to their respective functions, they can be divided into isolated handcarts (GL cars), voltage transformer handcarts (PT cars), and current transformer handcarts. (CT car), lower voltage transformer handcart (XPT car), metering handcart (JL car), isolation voltage transformer handcart (GL+PT car), fuse handcart (RDQ car), lower lightning arrester handcart (XBLQ car), grounding handcart (JD car) and nuclear phase handcart (HX car), and similar handcarts are completely interchangeable. The handcart has a positioning device in the work, test, and removal positions in the cabinet to ensure reliable interlocking. Equipped with special worm gear and worm mechanism, which can be pushed and retracted by shaking, which can realize the interchange of working, testing, and removing positions.

3. Breaker isolation room:

A specific track is installed in the circuit breaker compartment for the handcart to move. When the circuit breaker moves between the test position and the working position, the isolation valve automatically opens or closes to ensure that the staff does not touch the live body. The handcart can be operated with the cabinet door closed, and the position of the handcart in the cabinet can be seen through the observation window, and any signs on the handcart can be seen at the same time.

4. Busbar isolation room:

The main busbar is a single splicing and interpenetrating connection, which is fixed by the branch small busbar and the static contact box. The branch small busbar is connected to the static contact box and the main busbar by bolts, and no other support is needed. The main busbar is fixed with busbar bushings when passing through the side panels of adjacent cabinets, so that the air buffer between the connecting busbars is reserved. If an internal fault arc occurs, it can prevent it from penetrating and melting. Spread from other cabinets.

5. Cable isolation room:

The switchgear adopts the middle-mounted type, so the cable room has a large space, and the current transformer and grounding switch are installed on the back wall of the compartment.

The lightning arrester is installed in the compartment. After the handcart and the withdrawable partition are removed, the construction personnel can enter the cabinet from the front for installation and maintenance. Ample space can connect multiple cables per phase.

6. Relay isolation room:

The relay indoor board and panel can be installed with secondary components such as control and protection components, metering, display instruments, and live monitoring indicators. The top plate of the relay room also has a control line through hole that is convenient for construction, and the top plate can be turned over for easy installation.

7. Interlocking device:

1) The switch cabinet has a reliable interlocking device, which effectively guarantees the safety of operators and equipment;

2) When the earthing switch is in the open position, the handcart can move between the test position and the working position;

3) Only when the circuit breaker trolley is reliably positioned at the test position or working position, can it be operated;

4) When the grounding switch is closed, the handcart cannot be moved from the test position to the working position;

5) The grounding switch can only be operated when the handcart is in the test position;

6) Interlock between the secondary plug and the handcart position: The secondary plug can only be inserted or released when the handcart is in the test position; when the handcart is in the working position, the secondary plug is locked and cannot be released due to mechanical interlocking. .

8. Grounding device:

In the cable room, there is a separate grounding busbar of 4×40 mm2, which can penetrate through adjacent cabinets and make good contact with the cabinet.