Why Encapsulated Food-Safe Motors
A Breakthrough in Encapsulated Food-Safe Motors
After two decades of product development within the Duck line to drive the most intense washdown and sterilization spray applications in the industry, the top-of-the-line Extreme Duck® Ultra washdown motor is available. Engineered to the highest possible standards of protection, the Extreme Duck Ultra washdown motor offers increased durability in food and beverage related conditions.
The Evolution of the Washdown Duty Motor
Every aspect of wash-down spraying — the splash-back of scalding hot water, corrosive saltwater, acids and solvents, all pumped at high pressures in often high humidity or dusty environments — seems custom designed to destroy electric motors. And they did. The primary advantage of the Extreme Duck Ultra motor was that it prolonged the inevitable.
The original Washguard® (or White Duck) motor in the early 1990s was one of the first electric motors specifically designed for high-intensity, wash-down applications. A steel housing, precisely welded seams, tight seals and sealing washers all helped prevent water and small particles from infiltrating the motor and causing it damage and failures. At the time, no electric motor came close to completely blocking humidity, vapor, water spray, corrosives and the finest dust particles, but the White Duck motor came as close as technically possible. It became the washdown duty motor of choice for food-grade and pharmaceutical spray-down applications: work that required completely clean and sterile equipment. Still, even the White Duck motor was vulnerable to splash-back, harsh wash-down conditions and quicker endoflifein the field.
In 2004, the National Electrical Manufacturers Association (NEMA) adopted the International Elecrotechnical Commission (IEC) standards and test procedures to determine ingress protection (also known as IP rating) in enclosures. This rating is now universally recognized in multiple industries. The IP rating consists of the letters IP followed by two numbers that define the amount of protection the device has against foreign matter which could get inside its system and cause it to fail. The first number (0–6) indicates its protection factor against solids, such as dust. The second number represents its protection factor against liquids. Initially, the second number ranged from 0–6, but eventually that changed to 0–8 as new standards were established to enable manufacturers to prove a higher level of impermeability under even more demanding conditions. Then, in 2013, the IP69k rating established the ultimate ingress protection for the most extreme applications.
With the new IP standards in place, third party testing was conducted to rate the Extreme Duck Ultra motor. It was rated IP66, meaning it was dust-tight and protected against powerful jets of water. The motor was safe from the intense water spray it helped generate and suitable for most applications. But in other applications, the Extreme Duck Ultra motor faced far harsher conditions than just high-pressure water. The engineers believed they had to achieve better than an IP66 rating and build an electric motor that would stand up to the worst conditions and work reliably and continuously in any application.
Built for the Toughest Applications
The Extreme Duck Ultra motor’s primary application has been in the food and beverage industry. The Food and Drug Administration (FDA) has stringent standards for wash-down and equipment sanitation in all aspects of food production. For example, in defeathering and descaling systems, poultry moves through high-pressure spray and steam in every direction for 30–75 seconds at water temperatures up to 180°F (82°C). These electric motors are continuously exposed to the hot, intense backsplash while other wash-down systems constantly clean and sterilize every exposed surface in the processing plant. The wash-down and sterilization of equipment and containers often requires adding chemicals such as citric acid, chlorine and even diluted hydrochloric acid to the high-temperature spray. This only adds to the corrosive nature, as does the saltwater used in seafood processing plant wash-downs. Water and beverage companies require intense wash-downs at their bottle transfer lines and breweries need wash-downs after every step for every batch produced.
Today, the applications for washdown motors go beyond the food and beverage industry. Pharmaceutical manufacturing equipment and conveyors require complete cleanliness and sterility for product quality and to prevent cross-contamination. The motors propel machine-cutting fluids and water-cooling systems in a range of industries —even simulating rain and saltwater spray in automotive test tunnels. To handle all these applications and survive, the Extreme Duck Ultra motor would not only need be exposed to the hottest water, highest humidity, corrosive elements, and dirt and dust full-time without failure, but it would also have to perform in any mounting position while supporting inverter-driven, variable-speed applications.
This task required a high level of engineering focused on attaining near-absolute ingress protection. The goal was the IP69k rating, meaning the washdown motor was as close to total imperviousness as the IP standard could measure.
The Extreme Duck Ultra Motor Redesign
Regal engineers set out to completely redesign the top-of-the-line Extreme Duck Ultra motor, designing motors from ½ to 2 HP in most standard frames and adding two larger motor designs capable of up to 10 HP in new, larger frames for heavier-duty applications.
The first design decision was an all-stainless-steel housing, which provides far higher corrosion resistance than even carbon steel with composite coatings. Stainless steel also provides tight, precise welds as the first line of defense. Stainless steel allows a full-fact nameplate to be permanently etched onto the motor frame.
Then the engineers addressed their primary challenge — sealing, particularly around the rotating shafts. Instead of multiple seals, a new two-piece shaft seal with a flinger provided three points of protection from water, oil and chemicals. This ensured the motor could be installed in any orientation. This proprietary seal shaft was considered so critical that it underwent a year of testing — 8,760 hours — before the system was released for third party IP evaluation.
The conduit had always been the most vulnerable area for intrusion. In the new Extreme Duck Ultra motor, a welded pipe nipple at the ingress eliminated the need for an O-ring at the conduit, which often deteriorated and allowed fluid intrusion. At the conduit itself, engineers eliminated the most common field failure, lead wire wicking. In previous models, the motor came with a kit of connectors with heat-activated adhesives an end user could install to water-proof the lead wire, but many installations did not allow the use of heat guns to apply the adhesives, so the lead wire was often insufficiently protected. The engineers replaced this with non-wicking leads directly in the motor. The result was a complete, non-wicking power supply using a specialized seal and wiring fully encapsulated in epoxy, all color-coded for easy installation. The conduit box itself, also stainless steel, rotated 360 degrees for convenient wire placement.
The entire body assembly, including the end bells, was fully encapsulated with a proprietary epoxy using a vacuum assist, blocking virtually all air pockets where condensation could occur and eliminating the need for drain plugs and breathers on the motor. Once enclosed, the completely impervious windings incorporated an easily handled Q-Car™ rotor cartridge. The Extreme Duck Ultra washdown motor was ready for testing.
A Testing Success
Independent testing to earn an IP rating is rigorous and tightly specified, including the test equipment used and particles and fluids tested. As noted previously, the rating consists of two numbers: protection against solids and protection against fluids. The goal for the Extreme Duck Ultra washdown motor was the highest possible rating, IP69k. This rating establishes complete protection against any ingress of dust or high-temperature and high-pressure water. This certification would establish the Extreme Duck Ultra motor as ideal for conditions where equipment must be carefully sanitized, must withstand rigorous wash-down procedures, and, in many industries with dust and dirt issues, it ensures that dust cannot penetrate the motor and cause it to fail.
Previous Extreme Duck Ultra motor models passed dust resistance testing with perfect “6” ratings —dust-tight —and the new models were no different. Seams were tested with a 1 mm wire test probe, and then the motor was placed in a cabinet test chamber filled with blowing talcum powder or alum dust (with particles as small as 0.5 microns). The motor was subjected to a vacuum of up to 20 mbar for up to eight hours while inside the test chamber. Upon disassembly, no evidence of dust ingress was found in the motor. It was dust-tight—a “6”.
For fluid protection testing, the washdown motors were placed on turntables at 4–6 RPM. They were then continuously sprayed with scalding water with a temperature of 176°F (80°C) at a pressure of 1,160 –1,450 PSI for a minimum of three minutes —from just 4–6 inches away —until the entire surface of the motor had been sprayed.
The motors were fully disassembled and examined for any evidence of fluid penetration or residual moisture from steam. None was found, and the Extreme Duck® Ultra motors were certified IP69k.
The Extreme Duck Ultra Motor Today
Today, testing continues on every Extreme Duck Ultra motor produced. Each is completely pressure-tested before leaving the plant to ensure the motor is completely sealed. The Leeson® Extreme Duck Ultra washdown motor proves the value of a truly water-proof and dust-proof motor. It is an FDA-approved, food-grade, washdown motor completely impenetrable to liquids, chemicals and dust in any mounting position in any application.
The Extreme Duck Ultra Motor continues to offer these benefits:
- Pressure testing guarantees liquids don’t penetrate the motor, increasing motor life and reducing plant downtime
- Eliminating corrosion ensures longer motor life and reduces operating costs
- Protected washdown motor enhances reliability, flexibility and durability, decreasing operating expenses while increasing uptime
- Motor redesigns increase energy efficiency. The Extreme Duck Ultra motor meets the Department of Energy (DOE) Energy Security Act Mandate to meet NEMA Premium® Efficiency levels
The Leeson Extreme Duck Ultra motor won the 2015 Plant Engineering Product of the Year award and the 2016 Control Engineering Engineer’s Choice Award in both sponsor’s motor categories.
The legacy of the Extreme Duck Ultra motor carries into 2021 with the LEESON® brand releasing an enhanced smooth-weld model, the Extreme Clean® Ultra motor. Much alike its sister product, the Extreme Clean Ultra holds an IP69k rating, but will feature a patent-pending 360° smooth-weld conduit box for easier installation.
Check back later this year for more on the LEESON® Washguard® line as it continues to grow and revolutionize what it means to be a washdown duty motor.