How to choose a suitable stainless steel cabinet for the installation of distribution electromechanical engineering?

Key points of stainless steel cabinet selection in distribution electromechanical engineering

Combined with power distribution, electrical safety of mechanical and electrical equipment, environmental conditions, load grade and installation method, the selection criteria are given in different dimensions, taking into account compliance, durability and operation and maintenance.

First, determine the material brand (according to the environment, the first step)

Mainstream choose 304, 316, according to the need to distinguish:

304 stainless steel (general preferred)

Resistant to ordinary humidity, dust, indoor/semi-outdoor environment, rust-proof ability to meet the vast majority of distribution electromechanical scenes, high cost performance, indoor computer room, building power distribution, ordinary factory area, corridor weak current distribution box is preferred.

316 stainless steel (for harsh environment)

Salt spray resistance, acid and alkali resistance, chemical corrosion resistance, suitable for coastal areas, chemical workshops, sewage treatment plants, pickling workshops, open-air coastal distribution points, high corrosion conditions must be selected.

Pit avoidance: 201 stainless steel is not recommended, which is poor in rust prevention and easy to rust in short term, and does not meet the long-term operation requirements of distribution equipment.

Second, according to the protection level selection (IP level, corresponding to the installation environment)

According to the requirements of waterproof, dustproof and foreign body prevention of equipment, the commonly used standards in power distribution industry are:

IP30: cabinet of indoor drying machine room and power distribution room, which is resistant to solid foreign matter and waterproof, and is used in a purely indoor closed environment.

IP54: semi-outdoor, corridor, underground garage, ordinary outdoor upright box, dustproof+splash-proof, the most common grade of distribution machinery.

IP65: All-outdoor, rain-drenched, low-lying and easy-to-accumulate area, completely dustproof+high-pressure water spraying, necessary for outdoor power distribution terminal and outdoor electromechanical control box.

Third, choose the structural style according to the function & equipment type.

1. According to the installation form.

Wall-mounted cabinet: small power distribution circuit, terminal box, local control box, signal transfer box, installed on wall and column with narrow space, small size and convenient wiring.

Floor-standing cabinet: power distribution cabinet, PLC control cabinet, integrated power cabinet and multi-equipment integrated cabinet. The main equipment in the machine room and power distribution room is used, with strong load bearing and large internal expansion space.

Upright box: outdoor electromechanical point, outdoor power box, supporting vertical pole installation, off-ground layout, to prevent ground water immersion.

2. Internal structure requirements (special power distribution)

Bearing and reinforcing ribs: for high-power switches, transformers and heavy-duty modules, the cabinets must be reinforced, and the door panels and side panels should be thickened (conventional plate thickness: box ≥1.2mm, frame ≥1.5mm) to prevent deformation.

Wiring structure: reserved strong and weak current separation area, cable access hole and grounding bar installation position; The high-voltage distribution cabinet needs to be equipped with an independent cable bin, and the high-voltage and weak-current are separated to avoid interference.

Heat dissipation design

Low power consumption equipment: sealed box+natural ventilation holes/louvers;

High-power frequency converter, contactor and power module: ventilation net and heat dissipation louver are installed, and fan installation position can be reserved in high temperature environment.

Protective accessories: Insulating rubber strips, door locks (anti-theft locks are selected in outdoor/public areas) and grounding bolts are standard, which meet the electrical safety specifications.

Iv. electrical safety & engineering compliance requirements (power distribution must be checked)

Grounding design: special grounding terminals are reserved for cabinet, cabinet door and internal mounting plate. Stainless steel itself conducts electricity, and reliable grounding can prevent static electricity, leakage and lightning strike.

Insulation matching: insulation partition/insulation sheath shall be added to the internal mounting plate and bus area, and the metal cabinet shall be protected from the exposure of charged body.

Flame-retardant adaptation: the stainless steel body is nonflammable, and the matching sealing strip, cable trough and door lock fittings must be made of flame-retardant material, which conforms to the electromechanical fire protection code.

Identification position: the installation position of nameplate, loop identification and warning label is reserved to facilitate the later operation and maintenance inspection.

Five, special conditions special selection

High-temperature workshop: give priority to the structure of large air volume, and thicken the plate to avoid the aging of seals accelerated by high temperature; Reject fully enclosed box.

Low temperature/outdoor in the north: choose low temperature resistant sealing tape, the box body is designed to prevent condensation, and condensation drainage holes can be reserved.

Multi-dust workshop (metallurgy, building materials): high IP grade+detachable dust screen, which is convenient for regular cleaning.

Explosion-proof area: explosion-proof stainless steel case is selected, which meets the explosion-proof grade standard, and it is strictly forbidden to replace ordinary case.

VI. Trade-offs between cost and details

Conventional indoor power distribution: 304+IP30/IP54, with the best cost performance;

Corrosion/coastal environment: upgrade 316 directly, and don't replace it with 304;

Surface treatment: mirror/wire drawing can be selected indoors; Use matte wire drawing outdoors to reduce reflection, avoid scratches, and last longer;

Plate thickness: light-duty small box ≥1.0mm, conventional distribution box ≥1.2mm, heavy-duty floor cabinet frame ≥ 1.5 ~ 2.0 mm.

Quick selection comparison table

form

Use the scene recommendation material to recommend the IP grade recommendation style.

Indoor distribution room, computer room main cabinet 304 IP30 floor cabinet

Corridor, underground garage distribution box 304 IP54 wall hanging box

Ordinary outdoor point 304 IP65 vertical pole/wall hanging box

316 IP54/IP65 Wall-mounted/Floor-mounted Boxes in Coastal, Chemical and Sewage Plants

High temperature/dusty workshop 304 IP54 box with ventilation louver