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Like all motors, centrifugal and booster pump motors need to keep cool to work efficiently. Fans built into or onto these hard-working motors are designed to do just that: keep the motor cool so the pump keeps running.

 

There are typically two common types of motor enclosures: ODP and TEFC.

 

ODP

 

The ODP, Open Drip Proof, motor enclosure has open vents that bring outside air into the motor to flow directly over the windings. The air then exits the motor on the other end. With ODP, there is no need for an external fan.

 

For example, we use ODP motors on any of our surface pumps provided that they will be installed in a clean environment.

 

Some of the advantages of an ODP motor include better cooling which provides heat reduction while running. In some motors, a higher Service Factor may be applied by the manufacturer because of the lower operating temperature. Higher efficiency often is a result of an ODP enclosure.

 

TEFC

 

The TEFC, Totally Enclosed Fan Cooled, motor has a non-vented enclosure. An external fan is built on the end of the motor with a protective shroud. It takes the ambient air and blows it across the outside of the motor body. While a less efficient cooling method than an ODP, the totally enclosed motor guards against dust or other particles from entering or passing through the motor.

 

We use TEFC motors primarily on our vertical pumps to prevent foreign objects from falling on and entering the motor.

 

The biggest advantages of a TEFC motor are protection from foreign materials, and light moisture from entering the motor. Dust and other particles damage bearings and insulate windings, which creates higher temperatures. Normally, the enclosure of a TEFC motor has a larger surface area to dissipate some of the heat. Service Factors are often lower on the TEFC motor.

 

All Webtrol pumps are built to the customers request of enclosure type. It is one of the check points we use when clarifying a customer order for accuracy.

 

There are other motor enclosures available, although less common in the pump industry. There are TENV (Totally Enclosed Non-Ventilated) enclosures, washdown duty motors which also are non-ventilated, and specialty enclosures such as tropical enclosures. Any of these can be used on our pumps providing they are built to our required frame sizes, voltage requirements, and motor speed.