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The protective shell of the electrical control cabinet

Release time:

2025-06-09

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Abstract

Control Cabinet Protection Level Classification

According to the national standard GB 4208-2017 "Degree of protection provided by enclosures (IP Code)", the degree of protection of the control cabinet enclosure is represented by the two letters "IP" followed by two digits. The first digit indicates the protection level against solid foreign objects, ranging from 0 to 6. The larger the number, the stronger the protection capability. For example, 0 indicates no protection, while 6 indicates that it can prevent dust from entering or that the amount of dust entering will not affect the normal operation of the equipment; the second digit indicates the protection level against water, ranging from 0 to 8, with 0 being no protection and 8 being able to withstand long-term submersion without harmful effects.

Application Scenarios of Control Cabinets with Different Protection Levels

IP20 : Generally used in ordinary indoor environments, it can prevent solid foreign objects larger than 12mm in diameter from entering, but it has no protection against water. This level of control cabinet is mainly suitable for dry, low-dust, and splash-free indoor environments, such as ordinary production workshop control cabinets, where there are no special liquid or dust hazards.

IP54 : Can prevent a large amount of dust from entering and can prevent water splashing from all directions. It is often used in places with some dust and occasional water splashes, such as food processing workshops, where there is water vapor and a small amount of water splashes, but not long-term contact with a large amount of water.

IP65 : Completely prevents dust from entering and can prevent strong water jets from all directions. Suitable for outdoor or humid environments, such as the electrical control devices of outdoor billboards, which must be able to withstand wind and rain and prevent rainwater from entering through gaps to damage the equipment.

IP67 : Completely prevents dust from entering and can be immersed in a certain water depth for a short time without being damaged. This high-protection level control cabinet is used in more severe water immersion environments, such as the drainage system control cabinet in an underground parking lot, which may be submerged during heavy rain, but the equipment must be able to operate normally after the water recedes.

Methods to Achieve Control Cabinet Protection Level

Sealing

Door Seal : The control cabinet door and cabinet body usually use sealing strips, with materials such as rubber and silicone. For example, silicone sealing strips have good elasticity, heat resistance, and cold resistance, and can fit well with the door seam to prevent dust and water vapor in the air from entering.

Cable Entry Seal : For holes where wires and cables enter and exit the cabinet body, sealing putty or waterproof connectors are used. Sealing putty has strong plasticity and can fill gaps, while waterproof connectors use threaded tightening and sealing rings to achieve a pipe-like sealing effect, ensuring that the gaps around the cables are tightly sealed.

Material Selection

Metallic Materials : Some metal control cabinet enclosures are made of stainless steel, which has high strength and corrosion resistance. For example, control cabinets used near chemical workshops use 304 stainless steel, which can resist slight corrosion from acidic and alkaline gases. Its smooth surface also prevents dust from adhering, which helps reduce the risk of dust intrusion.

Engineering Plastics : For some lightweight control cabinets, engineering plastics such as polycarbonate (PC) may be used. PC material has high transparency, good insulation performance, and a certain mechanical strength. By treating the material surface specially, such as adding a protective coating, its protective performance can be improved to achieve the corresponding IP protection level.

Control Cabinet Protection Level Inspection

Solid Foreign Object Protection Inspection : Using solid shavings or needle-shaped probes of specific sizes, the method simulates dust and other solid foreign objects contacting the control cabinet enclosure to check whether foreign objects have entered the enclosure or whether the probe can touch the internal live parts, etc., to determine whether it meets the solid protection level requirements.

Water Protection Inspection : This includes using water jets and immersion to simulate different situations where water comes into contact with the control cabinet enclosure. For example, for IP65 level inspection, a water gun with a specified pressure will be used to spray water on the control cabinet from all directions at a certain distance and angle to check whether water enters the cabinet, thereby determining whether it meets the water protection level standard.

Control Cabinet Maintenance and Precautions

Regularly check sealing components, such as sealing strips, for aging, deformation, etc. If any are found, replace them promptly to ensure good sealing performance.

For control cabinets with ventilation holes, install protective nets. The aperture of the protective net must meet the protection level requirements to prevent dust and small insects from entering through the ventilation holes.

In special environments, such as coastal areas, consider the impact of salt spray on the protective performance of the control cabinet enclosure and appropriately increase protective measures or improve the protection level.

The protection of the control cabinet enclosure should be reasonably selected according to the actual application scenario. Through appropriate materials, sealing treatment, and regular maintenance, its protection performance can be guaranteed, thereby ensuring the safe and stable operation of the equipment inside the control cabinet.

Key words:

What environments are suitable for IP54 protection level?

What industrial scenarios are PLCs typically used in?