Waterproof or water-resistant?

Water-resistant, waterproof and watertight are three terms that seem to mean exactly the same and are often used synonymously. However, there are differences that are particularly important depending on the context. We explain what the terms mean and where the crucial difference is!

Watertight means that the structure and/or material of something, e.g. a housing, are such that water can hardly get in. However, this does not mean that water is completely prevented from getting in. If a material keeps water completely away, it is waterproof.

Water resistance, on the other hand, is not a question of how well a material can withstand water, but whether it will cause damage when exposed to water. For example, a cable is water-resistant, if the sheath plastic does not dissolve over time.

At a glance:

• Watertight: it is hard for water to penetrate.
• Waterproof: water cannot penetrate.
• Water-resistant: water does not cause damage.

Within an industrial application, there are many ways of transporting current, signals and data from one place to another. This is made possible by so-called connections or entire connection systems that connect a servo motor to a plant, for example, and thus ensure the power supply. A connection can involve a variety of electrical components, which depends on whether the entire connection is water-resistant, waterproof and/or watertight. Components that can be part of a connection system, for example, include:

• Cables and wires
• Plug connectors
• Conduit glands
• Switches

Water-resistant cables or waterproof plug connectors are not enough –
it comes down to the connection points!

It is not just the individual components that need to withstand the influence of moisture and water. In particular, the connection points where the power supply or data communication changes from one component to another are the critical weaknesses in the system that need to be tested for being waterproof and water-resistant.

A cable connection is the connection point at which two cables are connected to one another by means of a cable connector. A cable connector should therefore be waterproof in damp and wet environments. With a plug connection, on the other hand, two connectors (plug and socket) meet each other – typically when a cable is connected to a housing using a plug connector. Under no circumstances may the contacts inside the plug connector become moistened, otherwise it could result in a dangerous short circuit. A plug connector must therefore also be waterproof.

Both water-resistant as well as waterproof connection systems should be used in wet environments so that under no circumstance do water and electrical conductors come into contact with each other and at the same time so that the durability of the connection is ensured. But what does “wet” mean in this context?

In a wet environment, it is not just a cable that is laid under water, for example. It is much more common for cables to lie in dry conditions but become damp every now and again. This can be the case if liquid leaks into a machine or systems need to be regularly cleaned.

Generally, water-resistant and waterproof connection solutions are required when cables can get moist!

Typical environments where water-resistant and waterproof connection systems are used are:

• Plants in the food industry that have to be regularly blasted and disinfected with hot steam.
• Applications outdoors, such as on photovoltaic systems, antennae, systems in the chemical and construction industry, and much more.
• Cleaning plants that transport water and cleaning agents, such as washing plants and washing lines.
• Use on the high seas where particularly harsh conditions prevail, e.g. on ships, oil rigs or arbour facilities.
• Permanent use in water, e.g. up to a water depth of 100 m and a water temperature of 40 °C.
• Burial, e.g. for infrastructure construction.

Not all waterproofing is the same in electrical engineering.

In the context of cables, for example, a distinction is made between

• laterally waterproof and
• longitudinally waterproof.

When water cannot penetrate the wire plastic and get to the cores, this is known as a laterally waterproof cable.

If water penetrates at the plug connector into the end of the cable, but it cannot spread along the cores, as a jelly-like filling prevents the spread, this is known as a longitudinally waterproof cable.

However, in the context of devices or device components such as plug connectors or cable glands, the waterproofness is measured completely differently.

The IP protection class and the IP protection rating are often confused with one another or unclearly separated from one another because they are supposed to say the same thing. But there are differences that you need to know.

The IP protection rating describes whether a device or device component is protected by a housing against the ingress of foreign bodies and water.

The IP protection class, on the other hand, describes the measures taken against voltages that are dangerous to contact.

The IP protection rating tells you how waterproof a product is
and whether it still works perfectly when in contact with water. It applies to cable glands and plug connectors, but not to cables.

The protection rating is specified in so-called IP codes. "IP" stands for "Ingress Protection". The IP codes refer to the DIN EN 60529 standard, which is valid for Germany, and the ISO standard, which is valid internationally. IP codes must be specified together with the standard to which they relate.

An IP code is made up of the abbreviation "IP" in combination with two numbers or letters following this. In accordance with DIN EN 60529 (VDE 0470-1):2014-09 and ISO 20653, the protection rating is made up of the first and second code numbers in the tables below.

Degree of protection against solid foreign bodies

The first number here stands for protection against access and the ingress of foreign bodies such as dust or dirt:

Degress of protection against water

While the second digit indicates the degree of protection against water:

The lowest IP protection rating in relation to water is IPX0, where there is no protection, followed by IP X1, where there is protection against drops of water. The highest IP protection class is IP X9, which indicates that a housing is even waterproof against "high pressure and high jet water temperatures". Both IP X8 and IPX9 indicate that a product is waterproof and remains waterproof even at high water pressure (IP X8 up to 10 bar and IPX9 up to 100 bar).

You can find the IP protection rating that your product should meet with these questions:

• Where is the product used?
• What form of water will the product be exposed to? Drops of water? Spray of water? Splash water or jet water?
• Does the product need to withstand temporary or permanent immersion in water?
• Will there be high temperatures or high pressures that can affect the product?
• Which components will the product come into contact with? What do the interfaces look like?

At the same time, you should deal with the following question regarding water resistance:

• Is it pure H2O or does the water contain any salts, gases or organic compounds? Water-resistant materials are not necessarily corrosion-resistant. Only corrosion resistance ensures that a component does not rust, for example, and its function is not impaired. The salt spray test according to DIN EN ISO 9227, which tests the corrosion behaviour of a product, is decisive here. The test specimen is subjected to a salt spray in a standardised condition. After a defined period, the material is checked and evaluated. For example, it is possible to determine whether the surface of a component is seawater resistant and does not corrode in salt water.

Always remember the standard tests that we specify for product-specific purposes, which can be used to determine the environmental conditions to which a product can be exposed.

As a global market leader for integrated connection solutions, we offer a wide portfolio of UV-resistant products that are waterproof and water-resistant:

Power and control cables:

• The ÖLFLEX® HEAT 125 MC is suitable for a wide temperature range from -55°C to +125°C. It has approval from Germanischer Lloyd for use in shipping and can withstand both freshwater and saltwater.
• The ÖLFLEX® SOLAR XLWP is an electron beam cross-linked solar cable that complies with the strictest requirements in terms of operating conditions and standards (in accordance with EN 50618). Thanks to its optimised, unique LAPP cable design, the ÖLFLEX® SOLAR XLWP has a high level AD8 of lateral watertightness even after a prolonged period of time in water.
• When you need not only resistance to hot water and steam, but also chemical resistance to ammonia compounds, biogases, bio-oils and ester-based hydraulic oils, you can rely on ÖLFLEX® ROBUST 210.
• The H07RN-F, enhanced version is suitable for permanent underwater use up to a water depth of 100 m.

Data cables:

• The glass fibre cable HITRONIC® HUW1500, which is available in various variants, is extremely robust. It is cross and longitudinally waterproof.
• The ETHERLINE® ROBUST has been designed for connections in Ethernet systems where water resistance and chemical resistance are required.

Cable connectors:

• The EPIC® DATA CCR FA cable connectors are suitable for repair/extension and relocation of data cables up to Cat.7A and are resistant to the effects of water in accordance with IP 67.

Plug connectors:

• Some rectangular connector housings in the EPIC® ULTRA series offer protection rating IP 65 when plugged in, e.g. EPIC® ULTRA H-B 6.
• Circular connectors such as EPIC® SIGNAL M23 A1 or EPIC® POWER LS1 A1 have protection rating IP 68.
• Solar connectors such as EPIC® SOLAR 4Plus M or EPIC® SOLAR 4Plus F are typically IP68 tested as they are intended for outdoor use.
• Many plug connectors are also classified according to NEMA 250 and UL50E certified, making them suitable for the North American market. For example EPIC® H-A 3 MTG, EPIC® ULTRA H-A 3 TG or EPIC® H-B 6 TG.

Conduit glands:

• SKINTOP® HYGIENIC with smooth surfaces and stainless steel for hygiene-critical areas in the food industry (product zone).
• SKINTOP® ST-M made of plastic with IP 69 approval. Proven to withstand demanding cleaning procedures for machinery and systems with high-pressure cleaners and hot water.
• SKINTOP® INOX: corrosion/seawater-resistant stainless steel for offshore applications and the hygiene-critical food sector (spray zone).
• Special sealing brass cable gland SKINDICHT® SHV-M that meets protection rating IP 68 to 10 bar.

The location, the material used and the IP protection rating play a role when selecting a suitable product. For this reason, always pay attention to the application areas and product properties that you can find in the data sheet or on the relevant product page in our online shop.