What Is a Waterproof Micro Switch and Why Use It?

Micro switches are widely used in various fields, but they can be divided into various types according to different application situations. Among them, waterproof micro switches are one of the most popular types of micro switches. This article is written by a professional micro switch manufacturer in China to answer in detail "What is a waterproof micro switch" and "Why use it", hoping to help you better understand waterproof micro switches!

What Is a Waterproof Micro Switch

Definition Of Waterproof Micro Switch

A waterproof micro switch is a micro switch that reaches IP67 or even IP68 level through sealing means (such as epoxy sealant, O-ring, double-layer shell) in structure, which can effectively resist the entry of fine dust and water with a diameter less than 1.0 mm. Its test standard is that it can still operate normally after being immersed in 1m deep water for 30 minutes, which is a typical IP67 waterproof micro switch. The following is a standard diagram of IP level:

Structure Of Waterproof Micro Switch

It shares the core of "snap-action mechanism + spring sheet" with the basic micro switch, but the following parts have been strengthened for protection:

• ●Corrosion-resistant shell: PBT+30%GF, PA66 or stainless steel shell is selected to resist acid, alkali and salt mist.
• ●Plastic sealing ring: Silicone ring is pressed into the joint surface between the cover and the base and the wire outlet.
• ●Spring and contact: Tin-nickel-copper spring sheet is used, and silver alloy is commonly used for contacts, which takes into account conductivity and anti-melting welding.
• ●Lever: roller, short handle, long handle and customized form, which is convenient for customers to match different strokes.
• ●Terminal: quick-connect terminal, solder terminal or pre-installed wire, optional waterproof glue filling or injection molding.

Working Principle Of Waterproof Micro Switch

The core is still "spring snap action" - when the external force pushes the lever to reach the "action point", the internal spring flips instantly, making the moving contact and the static contact complete the connection and disconnection; after releasing the hand, it rebounds instantly under the action of the spring reset force. Compared with the basic micro switch, the principle is similar, the only difference is the shell seal: the waterproof type isolates moisture and dust through the shell glue seal, wire glue filling and exhaust valve design. Compared with the basic micro switch, it has better protection ability and longer service life.

Features Of Waterproof Micro Switch

IP67 Rating

The IP67 protection rating is its biggest feature, which can protect the intrusion of moisture and dust to the greatest extent, avoiding premature damage and failure of internal contacts and circuits. This is something that other types of micro switches cannot do.

Corrosion-Resistant And High-Temperature Resistant Shell

The shell adopts reinforced corrosion-resistant plastic shell, which is extremely strong and not easy to wear after long-term use. The continuous working temperature covers -40℃~+80℃, which meets high-temperature scenes such as engine compartments.

High load capacity

Common specifications 1A/250VAC, 3A/125VAC, DC side 0.5A/250V, thanks to the dual gold alloy contacts and silver tin oxide formula, the industrial equipment waterproof limit switch can work stably in the 5A/250VAC high load dual range.

Working temperature and weather resistance

The sealant layer is both waterproof and anti-ultraviolet. In addition, it must pass the -40℃ low temperature impact, high humidity 85%RH/85℃ and 96h salt spray test, and can be exposed to the sun outdoors for more than 7 years throughout the year.

Why use waterproof micro switches

Since the working principle of waterproof micro switches is not significantly different from that of basic micro switches, why use more expensive waterproof micro switches? In practical applications, many devices cannot avoid working in environments such as humidity, high temperature, condensation, oil mist or splashing of cleaning fluids. Basic micro switches will fail due to patina, arc oxidation or water vapor short circuits due to insufficient protection. Waterproof micro switches can significantly reduce the frequency of maintenance with IP67 sealing and corrosion-resistant housing.

Where waterproof micro switches are used

Automotive industry

Automobile door locks

The door lock body is in an exposed area to the external environment and is exposed to rain and car wash water all year round. If the internal switch is not sealed well, short circuit or feedback signal delay is likely to occur. The use of IP67 waterproof automotive door lock micro switches can ensure long-term stable operation in a high humidity and high corrosion environment in the lock body.

Electric seat adjustment position limit detection

The seat adjustment mechanism is usually installed near the vehicle chassis and is exposed to splashing water and moisture from the bottom for a long time. Ordinary micro switches are prone to adjustment failure due to contact corrosion. The use of sealed seat adjustment micro switches can not only resist moisture corrosion, but also support a long service life of 500,000 times.

Industrial equipment

GV unmanned logistics vehicle: outdoor operation anti-collision control

In intelligent warehousing and outdoor logistics systems, AGV needs to deal with rain, dust and continuous working conditions. Ordinary micro switches are prone to misoperation or failure. The G11 dustproof and waterproof micro switch is used as an anti-collision detection switch, which can withstand all-weather outdoor operation, ensure reliable system response, and effectively prevent collision accidents.

How to choose a suitable waterproof micro switch

Identify the use environment

When selecting a waterproof micro switch, you must first fully understand the working environment in which it is located, which is the basis for ensuring long-term reliable operation:

• Media type:What medium will the switch be exposed to? If it is a pure water environment, the general protection level is sufficient; but if it involves 3% salt spray (seaside environment), lubricating oil (machining equipment), or acid and alkaline cleaning fluid (food equipment), you need to choose a model with corrosion-resistant housing and sealing materials.
• Waterproof method:Is the environment static immersion or dynamic impact spray? IP67 can cope with short-term immersion, while continuous flushing, high-pressure water gun cleaning and other working conditions need to consider IP68 or even higher levels, and combine with glue sealing design.
• Using temperature:Is the ambient temperature extreme? Refrigeration equipment is as low as -30℃, and the engine compartment may be as high as +120℃. Products with wide temperature range working capabilities (such as -40℃ to +125℃) should be selected, and attention should be paid to whether their sealing performance is stable under temperature difference conditions.

Select the rated specifications according to the working voltage/current

It is essential to clarify the rated current and voltage. For high-voltage AC loads, look at the arc tolerance, and for low-voltage DC, look at the contact material and contact resistance; avoid "small-size switches cutting large inductive loads" leading to welding.

Clarify the size and size

The mechanical structure design must first determine the installation hole spacing, rod length, thrust direction, and details such as the installation hole spacing, lead wire outlet direction, and operating force direction to ensure accurate matching of structural parts. If there is no ready-made drawing, the supplier should be asked to provide 2D/3D contours, action stroke curves and schematic diagrams; an assembly tolerance of ±0.1mm is reserved during the design stage.

Check the safety certification standards

Whether it has international or regional authoritative certification is one of the key indicators to measure the reliability of waterproof micro switches:

• Common certifications include: UL61058 (North America), ENEC (EU), CQC (China), TUV (Germany), RoHS, REACH (environmental compliance), etc.
• Compliant products usually have passed multiple verifications such as high temperature ball pressure test, voltage resistance test, flame retardancy and electrical clearance, which can greatly reduce the factory audit and quality acceptance pressure of terminal manufacturers.
• For export products, it is recommended to choose switch models with multi-country certification to avoid the risk of batch returns due to inconsistent regional regulations.

Recommended to choose Unionwell waterproof micro switch

Unionwell has a fully automated injection molding + fully automated contact point riveting production line, which can produce 120 million micro switches per year, and provides one-stop services from shell color matching, wiring harness welding to IP68-level customization. It has passed IATF16949, ISO14001 certification, ISO9001 and other international certifications, and is widely used by European Tier1 automobile manufacturers and North American tool brands.

Conclusion

The waterproof micro switch combines the fast action characteristics of the traditional micro switch with the environmental protection capability of IP67/68 by upgrading the housing, sealing ring and contact system, providing a reliable status detection solution for new energy vehicles, smart home appliances, outdoor communication equipment, etc. Through this article, you have a deeper understanding of the waterproof micro switch.

And the waterproof micro switch is mostly used in automobiles. If you are interested in automotive micro switches, you may wish to learn about the Unionwell automotive micro switch page! If you are looking for a waterproof micro switch manufacturer, please feel free to contact Unionwell waterproof micro switch manufacturer, we will provide you with the most suitable waterproof micro switch type!