IP RATING: WHAT IT IS AND HOW TO CHOOSE THE RIGHT ONE?
What makes electronic equipment truly durable? The answer lies in IP certification, the international standard that classifies an electrical device’s ability to resist ingress of solid objects or liquids. Choosing the correct rating is essential for the safety of both equipment and people.
IP Rating: A standard for electrical safety
Ingress Protection (IP) defines protection against the ingress of solid objects and liquids. Dust and moisture not only threaten machinery, but can also compromise electrical insulation. The IP rating is therefore the objective criterion for determining a device’s suitability for an operating environment, ensuring reliable and code-compliant installations.
How to read the IP rating
The code consists of two numbers and, if applicable, a letter. The numbering is progressive: higher numbers indicate greater protection. If the second number is replaced by an X, it means there is no requirement for protection against water.
- The first number (0–6) measures protection against solid particles
- The second number (0–9) certifies resistance to liquids (pressure, quantity, and depth).
- When present, the third and fourth digits indicate resistance to mechanical impact.
For the most demanding environments, IP 69K guarantees total protection against dust, fumes, immersion in liquid, and high-pressure hot water jets.
The regulatory framework: the IEC 60529 standard and its application to Finder products
The reference standard is IEC 60529 (EN 60529 in the EU), which establishes technical requirements and test methods. To obtain the rating, each device undergoes laboratory testing that simulates the ingress of dust particles and liquids. In specific contexts, such as campsites, outdoor lighting, or public toilets, the minimum IP rating is specified by the standard.
For Finder products, the first number refers to protection against the ingress of solid objects into the relay, and against access to hazardous parts. The second number refers to protection against liquid ingress. The IP rating is related to normal use, whether on a socket or on a printed circuit board. On sockets, an IP 20 rating indicates that the socket is ‘finger-safe’ (VDE 0106).
Practical selection guide
Several factors guide the selection of the IP rating: the surrounding environment, exposure to dust and liquids, and legal requirements. To protect sensitive electrical and electronic devices from transient overvoltage, installing a surge arrester is recommended. The Type 3 models, Types 7P.31 and 7P.32 for systems with TT and TN-S neutral, are ideal for single-phase applications in flush-mounted installations (503 boxes) and for rail mounting. Compliant with EN 61643-11:2012, both feature an IP 65 rating. The 18 Series movement detectors feature protection ratings ranging from IP 40 for indoor devices, and up to IP 55 for outdoor ones (Types 18.A1 and 18.81).
- Offices, homes, and indoor spaces: Since these are generally dry environments, the most common standard for indoor use is IP 20 or IP 21.
- Bathrooms and kitchens: Exposure to splashes and condensation requires higher protection levels, such as IP 44 in the kitchen, and IP 67/IP 68 inside bathrooms and showers.
- Outdoor areas and gardens: Exposure to the elements, dust, and irrigation systems requires higher protection standards. The minimum rating is IP 44, rising to IP 54 or IP 55 in the most exposed areas.
To turn on lights based on ambient light levels, you can use the 10 Series light dependent relays with an IP 54 protection rating (suitable for outdoor installations), or the 11 Series devices. The latter, however, have an IP 20 rating, but are equipped with an external photosensitive element—Type 011.02 has IP 54 protection, and Type 011.03 for flush mounting has IP 66/67)
Lifespan and maintenance: Beyond the certification rating
- Industry and agriculture: In environments with fine dust or frequent washing, IP 65 or IP 66 ratings are used. Thermal management is a key factor in ensuring the longevity and efficiency of electronic components, especially in industrial control panels. The 7F Series filter fans—for electrical enclosures and control panels—(available in 24 V DC, 120 V AC, or 230 V AC versions) have a protection rating of IP 54 according to EN 60529.
- For underground or underwater installations, the rating increases to IP 67 / IP 68. The 72 Series level control relays can be used in the agricultural sector—for water level control in irrigation systems, water tanks, reservoirs, and underground wells—as well as in the residential and commercial sectors for controlling and monitoring water levels in swimming pools, fountains, and aquariums, or, for example, for flood protection in laundry rooms and for controlling submersible pumps.
The series includes Types 72.01, 72.11 and 72.51, all suitable for controlling the level of conductive liquids, and the Type 72.42 priority change relay—recommended for use with pumps, compressors, or motors when the system requires alternating loads. The range also includes the Type 72.A1 float switch for grey water, the Type 72.B1 float switch for black water, and finally, the space-saving Type 72.C1 float switch, all with an IP 68 protection rating.
The IP rating does not guarantee permanent protection. Protection can be compromised by external factors: An installation that does not comply with standards or is damaged can not only compromise safety but can also vois the system’s insurance coverage.
- Types of liquids: The IP ratings apply only to fresh water. Corrosive substances, solvents, or seawater can be harmful.
- Atmospheric agents: UV rays and temperature fluctuations can wear down materials and seals. Periodic inspections are essential to verify the system’s integrity.
- Natural wear and tear: The aging of materials degrades the seal. It is advisable to replace components at the first signs of deterioration to prevent permanent failure.
