Safety during CIP: IP69K-rated interlocks and safety switches

Strict health and safety standards in the food, beverage and pharmaceutical industries require all machinery used in the production process to be thoroughly sanitised at regular intervals to keep equipment clean and eliminate the risk of bacterial contamination. This automated cleaning process uses a mix of chemicals, heat and water to clean machinery, vessels or pipework without having to dismantle plant.

Because of the high pressures, harsh chemicals and high temperatures used in CIP, an adequate safety system is needed to protect personnel. This safety equipment must itself be able to withstand the CIP process which can seriously damage electronic circuits and instrumentation and cause substances such as dust and food waste to penetrate the equipment, causing it to fail. This usually requires an ingress protection (IP) rating of IP69K - the highest rating available.

Any interlocks and safety switches installed on safety equipment must also be IP69K-rated. Unfortunately most interlocks currently available offer very limited flexibility, focussing solely on achieving IP69K but failing to take into account other safety hazards manufacturers need to safeguard against.

If, for example, access to a machine subjected to CIP is required but there is a possibility that a worker could be hidden from view while inside the machine, there needs to be an effective safeguard in place to ensure the guard door cannot be locked closed and the machine restarted until the worker leaves the danger zone. The most effective and simple method to achieve this is with a safety key which a worker takes inside the machine to prevent inadvertent start-up.

With this in mind Fortress developed the amGardS40 range of highly robust, IP69K-rated, stainless steel electro-mechanical safety interlocks and switches specifically designed for the food, beverage and pharmaceutical industries. Modular in design, they allow for many different configurations to satisfy almost any safeguarding application, allowing customers to purchase modules and build up their safety system over a period of time.

Each module of the amGardS40 has a slim 40mm body allowing it to be easily fitted to a 50mm guarding section or other areas where space is limited. The range also enables users to incorporate basic machine control functionality into their interlocking devices. All control elements, including push buttons, lamps, selector switches and e-stops are IP69K-rated and can tolerate extreme CIP conditions. This minimises downtime while simplifying the access procedure as "gate release/ machine restart' can be controlled at the point of entry.

As the amGardS40 IP69K range maintains optimal performance even after being repeatedly hosed down by high-pressure washers and subjected to harsh CIP chemical cleaning agents, it helps manufacturers achieve a high Overall Equipment Efficiency (OEE) rating. It also allows electrical engineers to rest easy, knowing that machinery will not experience constant interruptions due to electrical failures as a result of dust and/or food waste penetrating the casing of the safety switches.

For more information about the amGardS40 range please go to www.fortressinterlocks.com.