Selecting an Enclosure for a Weatherproof Motor
Waterproof motors are designed to withstand moisture and debris in harsh environments. This allows them to operate safely and reliably.
TEFC motors use an external fan that blows air across cooling fins on the frame of the motor. This allows for cool, dry air to flow into the motor enclosure and keep the rotor and bearings clean.
Enclosure Types
When selecting an enclosure for a motor, there are many factors to consider. Understanding the available options can help you make a well-informed decision that reduces downtime and increases efficiency, as well as helping to keep your workers safe.
The first factor to consider is the environment and ambient conditions where the motor will be used. You should also take into account whether or not the motor will need to be frequently cleaned and sanitized or can stand up to caustic chemicals found in washdown environments.
Open drip proof (ODP) motors have ventilation holes that prevent the entrance of rain and other large particles, making them ideal for indoor protected areas that are dry and clean. They have an internal epoxy coating that resists corrosion from harsh cleaning solutions.
WP1 enclosures are similar to ODPs, but they have added screens that limit the entrance of water or larger solid foreign material. The ventilation passages include no less than three abrupt 90-degree changes in direction and a section with reduced air velocity to eliminate the entry of most solid foreign material into the cooling air.
TEAO motors use the heat generated by their internal components to self-cool. This allows them to operate in applications where a weatherproof motor consistent flow of external air is already present, like within the plenum of HVAC systems, ensuring effective cooling without the need for additional internal fans.
ODP Enclosures
Depending on the environment and conditions your motor will be exposed to, you’ll need to consider the types of contaminants that can affect it. Ingress of dust, moisture, and chemicals will all lead to decreased performance and shorter lifespans for your motor.
Ideally, you’ll want to use a weatherproof motor with an enclosure that will prevent contamination and reduce the likelihood of unplanned downtime. But with so many options to choose from, it can be hard to determine which type of enclosure is best for your needs.
Open Drip Proof (ODP) enclosures have ventilation holes that prevent water droplets and large debris from entering the motor. They’re typically used indoors in clean environments but can be used outdoors if the environment is fairly dry and free of large particles.
WP1 Enclosures are similar to ODPs, but with additional screens that block out larger particles and debris. This makes them better for clean, dry, or moderately dirty indoor environments.
Totally Enclosed Fan Cooled (TEFC) motors have a fan in a protective shroud that blows cooling air over the motor. They’re not airtight or waterproof, however, so they can’t be used in very damp or wet environments.
WP1 Enclosures
If an ODP motor is used in a wet, dirty environment, it’s important that it have adequate protection. Otherwise, the bearings and windings are open to contaminants that may cause damage over time.
For this reason, many technicians choose to use WP1 enclosures with ODP motors in wet, dirty environments. The ventilation holes in this type of enclosure are designed to prevent water droplets falling at an angle of 15 degrees or less from entering the motor. They also feature screens to prevent large particles from entering the motor.
WPII (or WP2) enclosures are more robust than ODP and WPI enclosure types, and they are ideal for wet environments. They have added ventilation passages that force air to make two right-angle turns before entering the electric parts of the motor, allowing smaller particles to fall out before they enter the motor. They also separate internal and external air so the cooling system can transfer heat efficiently.
This is a great option for wet or dirty environments where the motor needs to be cleaned and sanitized often. It has a water cooled heat exchanger that cools the recirculated air inside the motor and keeps the electrical parts from getting too hot.
WP2 Enclosures
WP2 enclosures are beefed-up versions of ODP and WPI enclosures. They have external ventilation passages that allow high-speed air to discharge, separating internal and external air. The flow path of the exhaust has at least three abrupt changes in direction, making it possible to identify and clean any contamination before it enters the motor. They also have a higher level of water resistance. This design makes them Waterproof DC motor wholesale a good choice for environments that must be sanitized or cleaned regularly. They’re typically used in food and beverage processing, medical manufacturing, and the pharmaceutical industry.
Another option for motors in harsh environments is the TEWAC enclosure. This design uses a shaft mounted fan to blow ambient air into the motor frame’s heat exchanger tubes, removing and cooling the internal heat from the external environment. It’s typically 2-3 DBA quieter than a WPII or TEFC design, but it could be a reasonable alternative when cooling water isn’t available.
Regardless of the type of motor enclosure you select, it’s essential to ensure that your electrical equipment is properly sized and installed. This will prevent moisture from contaminating the motor or creating an electrical hazard. Additionally, you should use monitoring devices like a megger and ammeter to track the motor’s performance over time and identify trends. Regularly checking the condition of your motor, and ensuring it’s sized and installed correctly, can extend its lifespan.