Which Pump Motor Enclosure Do I Need?

One of the most common questions we get at Crane Engineering is about motor enclosures. Maintenance personnel and engineers alike are uncertain which type is right for their application. They know it's critical to choose the right one, and for good reason. The wrong choice leaves pump motors vulnerable to adverse conditions and potential failure.

Which motor enclosure is right for my pump motor?

There are lots of options when it comes to motor enclosures. For instance, a common situation we run into is pumps in wash down applications. A water resistant motor enclosure is required if a pump is being cleaned and sanitized on a regular basis. In this case, Totally Enclosed Wash Down (TEWD) is most likely needed. This type of enclosure protect the motor from wet environments and high water pressure during wash downs.

Here's a few others we recommend for applications we see:

• Open Drip-Proof (ODP) - Often selected for indoor, clean, dry locations. Air circulates through the windings, cooling the motor. This enclosure prevents water droplets from entering the motor within a 15 degree angle from vertical. 

• Totally Enclosed Non-Ventilated(TENV) - Used most often in environments where a fair amount of dirt or dampness exists. The enclosure is not air tight, but has no vent openings. It also has no cooling fan.

• Totally Enclosed Fan Cooled (TEFC) - Like the Totally Enclosed Non-Ventilated enclosure, except it has a cooling fan. Used on pumps, compressors, fans, and other belt-driven and direct connected equipment.

• Weather Protected Type 1 (WPI) - As you might expect, the Weather Protected Type enclosures are for outdoor use. Their purpose is to prevent debris, dust, rain, and rodents from entering the motor. 

• Weather Protected Type 2 (WPII) - This enclosure is utilized on pumps that need a high degree of protection. Ventilation air is routed in such a way that airborne particles will not enter the electric parts of the motor. Air velocity is also minimized so moisture and dirt also will not enter the electric parts of the motor. 

• Explosion Proof (Exp Proof) - These enclosures are designed for hazardous applications. The enclosure will withstand an explosion from inside the motor casing, preventing gases or hazardous air particles from igniting. 

If you aren’t sure which motor enclosure to select for your pump or other fluid process equipment, check with an engineer well versed in pumps and motors. They can recommend the enclosure that will protect the motor and increase reliability and performance.