Facing the Challenge of Washing

Rigorous testing at a state-of-the-art hygiene laboratory verified that ABB’s Food Safe stainless-steel motors can withstand frequent sanitation. The motors emerged in full working order after being subjected to tests simulating years of operation in harsh washdown environments.

Maintaining product safety in food and beverage plants requires strict hygiene standards. Frequent washdowns are required to avoid contamination. The challenge is that electric motors used in these facilities can be damaged by aggressive cleaning. Motors specifically designed for these applications can help ensure food safety, improve reliability, and reduce the risk of unscheduled plant downtime. ABB Food safe motors to address the washdown challenge. They feature a stainless-steel housing to resist corrosion, and IP69 ingress protection to ensure that high-temperature, high-pressure spraying will not cause damage. They are also easy to clean, with a smooth, self-draining outer surface that has no angles where contaminants could gather.

Motors are unaffected by frequent washing with acid and detergents

In order to prove their long-term performance under realistic washdown conditions, ABB worked with a state-of-the-art hygiene laboratory in Västerås, Sweden, to devise a set of tests replicating industrial-type sanitizing procedures. The test regime reproduced typical cleaning practices in the food and beverage industry with a seven-stage cycle representing a full week of daily washdown procedures. Detergent and sanitizer were applied during every stage, with acid applied once per cycle. This reflects the common industrial practice of washing down with acid once each week. Temperatures up to 55 °C and pressures up to 25 bar were used. In all, a total of 158 cycles were performed, corresponding to 1,106 daily washdowns or 418 total hours of testing. Two IEC stainless-steel Food Safe motors were subjected to the tests and were largely unaffected and still in full working order at the end of the test program. No water, condensation or indication of corrosion was found inside the motors. All the three main O-rings and drain plugs remained tight.

No need for protective housings

For comparison purposes a standard painted aluminium motor was also tested. It started to deteriorate very quickly and failed well before the end of the test. The paint on the housing blistered and flaked off, and the shaft and other steel components suffered severe corrosion. Washdown chemicals penetrated both the terminal box and the main housing, causing short circuits between the phases and ground. The aluminium rating plate became detached from the motor. Paint flakes, rust, and particles could contaminate food products, leading to an expensive recall. Some plants try to get around these problems by protecting their standard motors with shrouds, but these shrouds cause new issues. Food particles can collect inside the shroud, hidden from view, providing the potential for bacteria to grow.
Food Safe stainless-steel motors eliminate the need for motor shrouds, providing 360-degree access for inspection and sanitization. The easy-to-clean surfaces also mean that less water and chemicals are needed. The tests prove that Food Safe motors withstand washdown conditions, giving plant operators confidence that they will help to reduce unscheduled downtime.