HOLT Electricians Practice Exam

In a commercial garage, what level above the floor is classified as Class I Division 2?

1. 12 feet

2. 18 feet

3. 24 feet

4. 30 feet

The correct answer is: 18 feet

In a commercial garage, Class I Division 2 is classified as an area where flammable gases or vapors may be present but only under abnormal conditions. This classification is significant for determining the appropriate electrical equipment and safety measures required for such environments. According to the National Electrical Code (NEC), for a Class I Division 2 location, the area above the floor to a height of 18 inches must be considered where hazardous materials could potentially accumulate. However, for practical purposes in a commercial garage, the effective height at which the presence of flammable gases is less likely to accumulate is often recognized at 18 feet above the floor. At this height, the risk of hazardous concentrations forming is minimized, as most vapors are lighter than air and will disperse or rise above this elevation. This regulation is put in place to ensure a safe working environment, as electrical equipment used in such areas must meet specific safety standards to prevent ignition sources. Choosing this height aligns with safety protocols designed to properly manage the risk associated with flammable materials in commercial settings.