MACHINE SAFETY


Supplementary letters are used to designate: F – Oil resistant


H – High voltage apparatus M – Motion during testing S – Stationary during testing W – Weather conditions


While other letters denote access to hazardous parts:


A – Protection of back of hand access B – Protection from finger access C – Protection from tool access D – Protection from wires


WASHDOWN CONSIDERATIONS One thing to keep in mind is that people are likely to spray at much closer distances than those stipulated in the IP-rated tests. While high-pressure washdown cleaning techniques enhance cleaning efficiency, and reduce water and detergent usage, minimising costs and environmental impact, it can impact the machine’s integrity, creating potential leakage points. To ensure problem-free operation in washdown areas, it is therefore important to


maintain the ingress protection rating during assembly and installation.


Category IP69K specifically relates to high- pressure washdown. Although the IP69K rating was originally developed for equipment used on road vehicles, and is only defined in the German DIN 40 050 version of the standard, it has now been adopted by many suppliers of enclosures, sensors and other machinery intended for use in washdown areas. When using the IP69K rating, the equipment is tested with a spray nozzle that is fed with water at 80°C, at a pressure of 80 to 100 bar, and a flow rate of 14 to 16 l/min. The nozzle is positioned 50 to 100 mm from the equipment under test at angles of 0, 40, 60 and 90 degrees for 30 seconds each. The equipment under test is mounted on a turntable that rotates at 5 rpm. At the end of the test, there must have been no ingress of water. A common mistake made by purchasers of machinery is to simply specify a IP69K-rated machine. However, this does not cover the fitting of any post-manufacture additions such as push buttons and indicator lights. Neither does it allow for any necessary drilling into the enclosure that is required for the addition of power cables once the machine is on site. All of this can impact the machine’s integrity, creating potential leakage points.


To ensure problem-free operation in washdown areas, it is therefore important to maintain the ingress protection rating during assembly and installation. As an example, this can be achieved by sealing pushbuttons and indicator lamps, as well as using IP69K glands for cable entries.


DESIGN CONSIDERATIONS


Enclosure designs that reduce the potential of ingress in the first place will also enhance long- term protection. For example, although water ingress protection is a key factor to consider when selecting equipment for use in washdown areas, there are other aspects that also need to be taken into account. This includes the material used in the fabrication of the equipment. While many materials cannot withstand this regular exposure, stainless steel can. For this reason, grade 316 stainless steel is usually specified for equipment being used in a washdown area as it has better corrosion resistance than other commonly available grades. Also, machinery that faces fluctuating temperatures, combined with heat-generating electrical circuits, will often cause condensation within a machine’s housing. As this can attack terminals and damage protected components, an anti-condensation system should be used.


IEC 60529 not only defines the different levels of protection provided by enclosures but also outlines the test methods required to verify that level of protection. IP testing minimises the risk of product failure in the field by assessing the degree of protection against mechanical intrusion, dust, accidental contact, and water into casings and enclosure. This ensures that machinery remains functional, reliable and safe for operators.


TÜV SÜD www.tuvsud.com/uk INDUSTRIAL COMPLIANCE |AUTUMN 2025 13


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