When it comes to high-voltage complete equipment, most people would immediately think of high-voltage and low-voltage distribution cabinets, as these electrical devices are quite common in daily life. High-voltage distribution cabinets refer to electrical products with voltage levels ranging from 3.6kV to 550kV that serve switching, control, or protection functions in power generation, transmission, distribution, power conversion, and consumption within power systems. They mainly include high-voltage circuit breakers, high-voltage disconnectors and grounding switches, high-voltage load switches, high-voltage automatic reclosers and sectionalisers, high-voltage operating mechanisms, high-voltage explosion-proof distribution devices, and high-voltage switchgear. The high-voltage switchgear manufacturing industry constitutes an important part of the power transmission and transformation equipment manufacturing sector and holds a crucial position in the entire power industry.
High and low-voltage complete distribution cabinets have wide-ranging applications, primarily suitable for distribution systems in power plants, petroleum, chemical, metallurgical, textile, and high-rise building industries. The following are key considerations for the installation and construction of high and low-voltage electrical complete equipment:
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Cabinet Installation: According to the layout in the construction drawings, high and low-voltage complete distribution cabinets should be sequentially positioned on the base channel steel. For individual cabinets, vertical alignment of the cabinet face and sides can be adjusted using shims, but no more than three shims should be used, and they must be securely welded. After positioning all cabinets in a row, their levelness and panel deviation should be adjusted to comply with construction specifications.
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Wall-mounted distribution cabinets can be fixed to walls using expansion bolts, but for hollow bricks or block walls, dovetail bolts or through bolts should be pre-embedded for secure fixation.
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For installing distribution cabinets, a sleeve box should be pre-embedded, and the rear panel should be flush with the wall surface after installation.
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After completing cabinet adjustments, the cabinet body should be firmly fastened to the base channel steel using bolts.
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Cabinet Grounding: Each cabinet should be individually connected to the base channel steel. Copper wires can be used to reliably connect the PE busbar inside the cabinet to the grounding bolt, with spring washers added to prevent loosening. Additionally, each cabinet door should be separately connected to the PE busbar using braided copper wires.
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When connecting the cabinet top to busbars, ensure to use the matching busbar wrench for proper tightening as required, and apply neutral Vaseline to the contact surfaces. During busbar connections between cabinets, pay attention to whether the busbars are too close to other components or the cabinet body, and ensure correct phase sequence.
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Control Circuit Inspection: Check whether wiring has become loose due to transportation or other factors, and tighten all connections one by one. Verify if any electrical components are damaged. In principle, control circuits in cabinets are calibrated before leaving the factory, so no unauthorized adjustments should be made to internal wiring. If issues are found, contact the supplier.
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After control wire verification, form each core wire into a loop and connect it to terminal blocks using galvanized screws, washers, and spring washers. Generally, only one wire should be connected per terminal on each side of the terminal block, with a maximum of two wires allowed, and washers must be placed between two wires. Stranded wires should be tinned, and broken strands are strictly prohibited.
The above summarizes and analyzes the "Applications and Considerations for High and Low-Voltage Complete Distribution Equipment." We hope this information proves helpful! For more knowledge about electrical systems, please consult Yingquan Electric's technical team.
