Top Considerations of a Washdown Duty Motor
Washdown duty motors are constructed to withstand a wide range of environments and applications. These areas of usage have the potential for caustic cleaning and disinfectants in the pharmaceutical world to heavy wash down in milk processing environments, customers have an extensive range of needs for their motors. It can be difficult to sort through the noise of motor listings, but by focusing on these top considerations you’ll be able to narrow down your options quickly!
Enclosure Type
A motor’s enclosure is its first defense against dirt and contaminants. It determines the extent of the seal and protection the motor receives against its environment. As with any protection measure there is a wide array of options to consider. Thanks to the International Electromechanical Commission (IEC), an ingress protection (IP) rating system was developed in order to standardize the protection a motor can deliver.
IP Ratings offer a numerical scale gauging an enclosure’s tolerance to solids and water. The levels range from its lowest IP00 (no solid object or water protection) to its highest rating IP69 (dust tight and protected against high pressure and temperature water jets).
Encapsulated motors such as the LEESON® Extreme Duck® Ultra sit at the top of this category with an IP69 rating. These motors are traditionally used in meat processing environments due to high stakes around potential contamination and need for thorough wash down.
IP Rating can be critical to the success of both the motor and the application.

( Source: International Electromechanical Commission (IEC) )
Frame Material
Every washdown environment has its own chemical and sanitation requirements depending on the nature of the business. In order to deal with these necessities, your motor material must be able to handle water, cleaning solutions, or caustic liquids.
Regal Rexnord’s washdown duty motors are available in a white epoxy coating and stainless steel exterior. Each material offers different advantages to the end-consumer in terms of chemical resistance.
Regardless of the cleaning and washdown solutions used, its also important that any chemicals present in the environment react well with your equipment. Below you’ll find a comprehensive list of chemicals, their concentrations, and exposures in relation to how they react with stainless steel or white epoxy coatings.
Chemical Resistance Comparison
| CHEMICAL NAME | % CONCENTRATION | EXPOSURE | WHITE EPOXY | STAINLESS STEEL |
|---|---|---|---|---|
| Fresh Water | 100 | Continuous | Excellent | Excellent |
| Salt Water | 5 | Continuous | Excellent | Excellent |
| Salt Brine | Dilute | Continuous | Fair | Good |
| Ammonium Hydroxide | Dilute | Continuous | Good | Excellent |
| Calcium Hydroxide (Lime) | 100 | Intermittent | Good | Excellent |
| Citric Acid | 10 | Continuous | Good | Excellent |
| Ethylene Glycol | 100 | Continuous | Excellent | Excellent |
| Hydrochloric Acid | 37 | Intermittent | Good | Poor |
| Lactic Acid | Dilute | Intermittent | Excellent | Excellent |
| Lactic Acid | 100 | Intermittent | Fair | Fair |
| Mineral Spirits | 100 | Continuous | Excellent | Excellent |
| Potassium Hydroxide | 50 | Intermittent | Fair | Fair |
| Sodium Hydroxide | 5 | Continuous | Fair | Excellent |
| Sodium Hydroxide | 20 | Continuous | Fair | Excellent |
| Sodium Hydroxide | 50 | Continuous | Excellent | Excellent |
| Sodium Hypochlorite (Bleach) | 15 | Intermittent | Excellent | Excellent |
| Sulfuric Acid | 10 | Intermittent | Fair | Fair |
| Mineral Oils | NA | Continuous | Excellent | Excellent |
| Vegetable Oils | NA | Continuous | Excellent | Excellent |
| Cutting Oils | NA | Continuous | Excellent | Excellent |
| Detergents | NA | Continuous | Excellent | Excellent |
| Hydraulic Fluid | NA | Continuous | Excellent | Excellent |
| Lubricating Oils | NA | Continuous | Excellent | Excellent |
| General Weathering | NA | Continuous | Fair | Excellent |
| Mold/Mildew | NA | Continuous | Excellent | Excellent |
| Light Abrasion | NA | Continuous | Excellent | Excellent |
| Heavy Abrasion | NA | Continuous | Fair | Excellent |
Insulation
Just as important as an exterior is for a washdown motor, the inner workings require protection in the event any solids or liquids contaminate the motor. Many motors take a pro-active approach with solutions like moisture-resistant interior coatings that help inhibit corrosion within the motor.
In LEESON White Duck™ motors their frame, base, end shields, rotor, and interior components are protected by enamel and polyester compounds with resistance to moisture, acids, alkalies, and oils. In addition, they have a moisture resistant IRIS insulation system that assures long life on inverter service with windings immersed and cured in a polyester insulating compound.
We go to great lengths with our wash motors to ensure you have the best solution for your application, that means providing you with options to the best materials, range of IP ratings, and insulation needs you could need.
To discuss a new washdown solution, Contact Our Experts at the link below.
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