Choosing the Right Electric Motor Enclosure Type June 2, 2022

The right electric motor enclosure will decrease your maintenance costs, extend the life of your motor, and enhance motor performance. But it can be tricky knowing what enclosure type you need.

What’s the Deal with Electric Motor Enclosures?

Let’s start with what electric motor enclosures do; what purpose do they serve? For starters, they provide protection from the elements (like moisture, chemicals, and abrasive particles). The enclosures also protect other equipment and people from the high temperatures and heat generated by the motor, promoting the safety and performance of nearby equipment.

Electric motor enclosures also ensure that your AC motor (if that is the case) is efficiently cooled, which will impact performance. Enclosures also keep noise levels at a minimum, contributing to a comfortable and productive working environment.

Types of Electric Motor Enclosures

Open Drip Proof (ODP)

The Open Drip Proof (ODP) enclosure protects against falling liquid droplets entering the motor from vertical angles of up to 15 degrees. These enclosures allow outside air to freely circulate through the motor windings to cool the motor efficiently. These enclosures are primarily used in dry, clean, indoor applications and environments.

Totally Enclosed Fan-Cooled (TEFC)

TECF motor enclosures are enclosed so that inside and outside are prevented from mixing. But the frame is not entirely airtight or watertight. An external shaft-mounted fan at the rear of the motor blows air over the outside of the motor frame to cool it. This versatile enclosure type is typically used on fans, pumps, compressors and belt drives.

Totally Enclosed Water-to-Air Cooled (TEWAC)

TEWAC motor enclosures use a heat exchanger to keep the motor efficiently cooled. The heat exchanger contains fluids like fresh water that draw the heat in from the circulating hot air.

Totally Enclosed Non-Ventilated (TENV)

TENV motor enclosures are very similar to TEFC types, except they have no fan cooling system and they rely on the surrounding air to keep the motor temperature stable. They are a little bit more finicky because they require more TLC. For example, you’ll need to avoid frequent stops and starts, which build heat inside the motor windings. As a result, this type of enclosure is more common with smaller motors.

Weather Protected Type I (WPI)

WPI (or WP1) enclosures are beefed-up versions of ODP enclosures. They have protective screens that prevent large particles from making their way into the motor.

Weather Protected Type II (WPII)

WPII (or WP2) enclosures are beefed-up versions of ODP and WPI enclosure types. They have external ventilation that allows high-speed air to get out without entering internal passages, separating internal and external air.

Washdown (WDN)

A WDN motor enclosure is ideal for motors that need to be sanitized or cleaned often. You will typically see these enclosures in food and beverage processing, medical manufacturing, and the pharma industry.

Questions to Narrow Down Your Motor Enclosure Type

What is the motor’s application?
Will the motor be placed inside or outside?
Is there a risk of high humidity or water exposure?
What type of motor are you working with? Including the frame size, type, specifications
Will your motor and enclosure need to be cleaned and sanitized regularly?
Could heat from the motor pose a safety hazard?

At Duke, our team of motor pros will work with you to find the proper motor enclosure for your application. Our objective is always to save our customers time and money, so contact us today before making your decision!