When choosing a waterproof and dustproof connector, is it enough to just look at the IP rating?

The IEC 60529 standard defines ingress protection (IP) ratings using standardized levels, represented by an IP prefix followed by two digits: the first digit for protection against solid objects and the second for protection against liquids. There are also some national or regional equivalents, such as ANSI 60529 (USA) and EN 60529 (Europe).

Figure 1: IP protection rating code structure (Image source: CUI Devices )

Further explanation of the meaning of the numbers in the IP protection code is shown in the following table (Figure 2). For example, IP56 protection means that the component is not only dust-proof, but also protected against strong water jets.

Exposed external connectors are a common entry point for water and dust to enter a device. It is critical to determine the intended use of the application as early as possible so that when selecting an exposed connector, its IP rating meets the minimum requirements of the system.

IP-rated connectors are often used in devices with external ports such as audio, USB, or DC power jacks. In these cases, the proper IP rating protects all internal circuitry from accidental ingress of water or dust when no plug or external device is connected. Other situations, such as connections between industrial cables, may require a connector and plug combination that is fully sealed when mated. A fully sealed connection prevents dust and moisture from interfering with the signal, or damage to components during operation due to high-pressure water ingress or even complete immersion.

Figure 3: Cable plugs and connectors with locking and sealing interfaces (Image source: CUI Devices)

However, it is important to note that even if the plug and connector are individually IP rated, this does not automatically create an IP rated connection. Unless the design incorporates an additional sealing mechanism, such as the screw terminal interface shown in Figure 3, dust and moisture can still easily penetrate the connection interface (Figure 4). If the interface is not properly sealed, it may interfere with the signal or cause damage to the internal circuitry.

Figure 4: Dust and moisture can still easily intrude into a typical connection (Image source: CUI Devices)

As portable devices become more popular, the demand for durable components has increased accordingly. CUI Devices has launched a series of IP67-rated connectors, including USB receptacles , 3.5mm audio jacks and DC power jacks , to provide designers with flexible choices for harsh environment applications. These connectors use custom-shaped gaskets or O-rings to provide effective sealing, thereby achieving dust and water protection and can be fully submerged in water up to 1m when not connected.