What should be paid attention to in the design and processing of electrical cabinet customization?

Matters needing attention in customized design and processing of electric cabinet

First, the core points in the design stage

Adaptation of working conditions and environment

Identify the installation environment: indoor/outdoor, dust, humidity, corrosive gas, oil stain, high and low temperature, and determine the protection level (IP54, IP55, IP65, etc.).

Outdoor cabinets should be protected from rain, sun, condensed water and rust, and equipped with cooling fans, air conditioners, heaters and sealing strips when necessary.

Size and layout planning

Reasonably determine the length, width and height of the cabinet according to the number of components, wiring space and heat dissipation distance.

Reserve maintenance space, door opening angle, slot/guide rail installation position to avoid poor heat dissipation and difficult wiring caused by too dense components.

Strong and weak current are arranged in zones, and power lines and signal lines are routed separately to reduce interference.

Electrical specification and safety

Conform to GB/IEC standard, and reasonably configure air switches, contactors, relays, terminals and grounding bars.

Reliable grounding system: cabinet grounding, functional grounding and shielding grounding are separated or standardized.

Insulation distance and creepage distance shall meet the voltage level to prevent short circuit and ignition.

Heat dissipation and temperature rise control

Calculate load power and total heat generation, and design natural convection or forced heat dissipation.

High-power devices should avoid closed dead angles, and frequency converters and servo drivers should pay attention to unobstructed air ducts.

Avoid direct sunlight and dense stacking, and install cooling fans/fins if necessary.

Electromagnetic compatibility EMC

Shielded wires are used for signal lines, and one or both ends of the shielding layer are reliably grounded.

Input and output are routed separately, and isolation transformers, filters and surge protectors are used.

The metal shell of the cabinet is continuously conducted to improve the shielding effect.

Inlet and outlet line and interface design

Reserve the position of cable inlet and outlet, glen head and waterproof joint, and determine the number and aperture in advance.

The bottom/side wiring mode is unified, which is convenient for on-site wiring.

And relates to the selection of special connectors for explosion-proof and anti-corrosion scenes.

Second, the processing and process control

Material and plate selection

Commonly used cold-rolled steel plate (spraying) and stainless steel 304/316 (corrosion resistance).

Plate thickness: cabinet door ≥1.2mm, cabinet body ≥1.5mm, and load-bearing parts are strengthened.

Machining accuracy of sheet metal

The bending and punching dimensions are accurate, ensuring the uniform gap of the cabinet door and smooth opening and closing.

Standardization of installation holes and guide rail holes to avoid assembly dislocation.

surface treatment

Pickling and phosphating → electrostatic plastic spraying/baking paint to ensure adhesion and rust prevention.

Outdoor and chemical environments need thick coating or stainless steel body treatment.

Assembly and wiring technology

The components are firmly fixed, and the torque of the terminal reaches the standard to prevent loosening and heating.

The wire number is clear, the wiring is horizontal and vertical, and the binding is standard, which is convenient for maintenance.

The strength of door hinges and locks is sufficient, and frequent switching is not easy to deform.

Identification and nameplate

Configure loop identification, component labels, warning identification, wiring diagram and schematic diagram.

The nameplate shall be marked with model, power, current, protection level and manufacturer information.

III. Testing and Acceptance

Insulation withstand voltage test

Ground and interphase withstand voltage test, insulation resistance detection.

Power-on no-load test

Each loop operates normally without short circuit or misoperation.

Temperature rise and on-load test

Run under rated load, and the temperature rise is within the allowable range.

Protection level inspection

Water-proof and dust-proof test, no leakage of seal.

IV. On-site Adaptation and Post-maintenance

Consider transportation, hoisting, door opening direction and landing/hanging mode.

Reserve spare circuits, spare terminals and spare space to facilitate later expansion.

Dust-proof net is added to the radiator, and the wearing parts (fan, sealing strip) are easy to replace.