What is an Explosion Proof Motor?

by | Jan 25, 2016 | Industrial Goods and Services

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Commercial motors perform many kinds of duties for Texas businesses these days. Some are in clean and controlled environments. However, many industrial motors work hard in areas where contaminants could cause serious damage if not protected. In fact, some applications call for an explosion proof motor. Here is more about this type of protection and why it is so important.

Defining the Explosion Proof Motor
Explosion proof refers to the motor encasement. These motors must be completely enclosed and capable of withstanding and internal explosion caused by volatile vapor or gasses. For example, a standard motor may emit sparks that could ignite flammable vapors. To prevent this from occurring, an explosion proof motor in Texas must be protected from sparks and excessive heat.

Determining Risks
When choosing the right commercial motor, four risk factors must be considered. They are AIT, Class, Division, and Group.

AIT
This refers to auto ignition temperature and takes into account the hazardous atmosphere or materials present and their kindling point (the lowest temperature where ignition can occur). AIT refers to the temperature in which spontaneous combustion may happen (without sparks or fire). Several things are taken into account when determining AIT, including O2 concentrations in the air, system volume, and pressure.

Class
To help determine the type of explosion proof motor needed in Texas, the NEC defines 3 specific classes of hazardous locations:
* Class I – area contains vapor or gasses considered to be flammable. Commonly found in the gas and oil industry.
* Class II – Flammable dust or dry materials in the air. This may include flour mills and processes creating dust.
* Class III contains filings or residue that can be easily ignited. May be found in the textile industry.

Division
Division is determined by the environmental conditions, as opposed to the materials (class). Division 1 refers to an area in which the possibility of explosion or fire exists when operating normally.

Division 2 concerns hazardous materials stored in the area and an accidental explosion could occur.

Group
The classes are divided into groups depending on the types of materials they are exposed to. For example, groups A, B, C, and D are in class I. E, F, G, and H are designed to classify materials in class I.

Explosion Prevention
An explosion proof motor in Texas is not created to prevent an explosion. Instead, it is designed to contain an explosion so a major incident will not occur. To determine the best motor for your applications, it’s best to consult with your provider. They will help you choose the most cost-effective motors with maximum safety features for your business.