7 Common Enclosure Types of AC Motors.

Good day steemit community!
This post is related to my previous post about parallel running of generators. Now, it will focus on the enclosure of an AC motor. As we go through, we will learn what is motor enclosure, why we need motor enclosure and the common enclosure types.

If you are interested with motors and generators, you can read my previous post;
Parallel Running of Generators

What is Motor Enclosure?

Motor enclosure refers to the frame of the motor.

Why we need motor enclosures?

The main purpose of this enclosure is to provide a protection from environment outside. This includes rain, corrosion, dirt and other foreign objects. AC motors are typically made of bearings, wires, winding and other mechanical parts. These are vital and it is needed to be protected. It does not only protect the internal parts, but also it allows generated heat to dissipate from the motor. Thus, enclosures provides a cooling system for the motor depending on enclosure types.

Common Enclosure Types

1. Open Drip Proof (ODP)

ODP

It has an open frame that allows air to circulate through the motor windings. But, it prevents liquid drops falling into motor within 15 degree angle from vertical.

2. Totally Enclosed Fan Cooled (TEFC)

TEFC

A dust-tight frame typically installed in the airstream and air movement from a fan passes over the motor for cooling

3. Totally Enclosed Non-Ventilated (TENV)

TENV

This is similar to TEFC but it has no cooling fan and cooling only relies on simple convention for the heat to dissipate from the motor frame. It has no vent openings, tightly enclosed, but not airtight. This type of enclosure should be used in a clean air environment.

4. Totally Enclosed Air Over (TEAO)

TEAO

This is similar to TENV motor. It has an external fan mounted to shaft at same speed of fan motor shaft for cooling the frame. It is typically used out of airstream, or airstream with direct or belt drive. Because of its construction, this motor is quite bit versatile.

5. Totally Enclosed Wash Down (TEWD)

TEWD

This type is an enhancement of TENV, TEAO and TEFC designed to withstand high pressure wash downs or applications where there is high humidity, moisture, wet environments. It can be used in belt and direct-drive fan application and available for severe duty enclosure. This is totally enclosed, hostile and severe environment motors.

6. Explosion-proof Enclosures (EXPL)

EXPL

This type is designed to withstand an explosion of some gas or other vapor inside the motor. It is totally enclosed machine and prevent the ignition outside the motor by sparks, explosion and flashing. Motor with this type are labeled for classes. Class 1 is for vapors and gases and Class 2 is for combustible dust. From classification, it was group with A, B, C and D and these groups identify the type of vapor or dust which motor is suitable to apply.

7. Hazardous Location (HAZ)

HAZ

This motor applications are classified by type of hazardous environment, characteristics of material creating hazard, probability of exposure to environment and maximum temperature level that considered safe substance creating hazard. Classified as Class I, Class II and Class III. Class 1 is for vapors and gases. Class 2 is for combustible materials. Class 3 is for easily ignitable fibers, like cotton, sisal, hemp, cocoa fiber and other materials of similar nature.

For more details on AC motor enclosures, you can check my sources.
Here are my sources;
Source 1
Source 2
Source 3

Best Wishes,

@thinkingmind