Washdown motors are used in industries ranging from food processing to pharmaceutical manufacturing. These motors drive machines that bottle milk, mix molten plastics, and do everything in between. But regardless of the application, all washdown motors must be two things: cleanable and reliable. Cleanable, because many of these products are destined for human consumption. And reliable, because one motor failure in a production line can cost thousands of dollars in downtime, and potentially spoiled batches of product as well.
But reliability is hard to ensure in a washdown environment. Heat, humidity, and cleaning chemicals, as well as high-pressure streams of water, all take a toll on motors. Washdown motors sport a number of features to protect against these harsh conditions. Many of these features serve to protect the bearings, like special seals and moisture-resistant bearing grease.
In addition to environmental hazards, washdown motor bearings are also at risk from internal hazards, when motors are controlled by variable frequency drives (VFDs). All motors on drives are susceptible to electrical bearing damage because of the nature of drives' output. VFD power causes voltage to build up on the motor shaft. Without protective measures, this voltage will discharge by arcing through the bearings, causing damage and eventual failure. A shaft grounding device can make washdown motors more reliable by mitigating this damage. But USDA regulations would prohibit an external shaft grounding brush.
Instead, a washdown motor needs an internally mounted long-lived shaft grounding ring, like the AEGIS® SGR. Unlike spring-loaded carbon grounding brushes, AEGIS grounding rings don't require adjustment and don't typically wear out over a motor's lifetime. So they can prudently be installed inside of motors. AEGIS rings are also the only shaft grounding product to offer a warranty against electrical bearing damage. In fact, they carry a two-year extended warranty, on top of the manufacturer's warranty.
Washdown motors are available with AEGIS rings factory-installed. For example, LEESON has two lines of stainless Washguard® motors that come with AEGIS inside by default: the Premium All-Stainless and Extreme Duck Ultra lines.
The whole point of a washdown motor is to have a motor that will keep running reliably in spite of the severe cleaning it's subject to. With that in mind, why would you not want the motor to be as reliable as possible?
AEGIS Rings also come with a 2-year extended warranty against bearing fluting damage. No other form of protection against VFD-caused bearing damage offers a warranty like this.
To learn more about AEGIS shaft grounding and best practices for electrical bearing protection, sign up for a training. We offer monthly live training webinars, and we can also visit your facility to review your exact application.