Special Occupancies, Equipment, and Hazardous Locations
What the exam tests
Special-occupancy questions test classified locations, health care, assembly, pools, emergency systems, motors, and transformers under NEC Articles 500–517, 680, 700, and 430.
Core rules
- Class I locations contain flammable gases or vapors; Division 1 is normally hazardous, Division 2 only under abnormal conditions.
- Class I Division 1 requires explosionproof or intrinsically safe equipment, threaded rigid metal conduit, and conduit seals within 18 in of enclosures.
- Health care essential electrical systems separate life-safety, critical, and equipment branches; emergency systems require periodic testing.
- Pool areas require equipotential bonding of metal parts, forming shells, and water; GFCI protection is required for specified pool equipment.
- Motor disconnects must be within sight of the motor and controller unless the disconnecting means is lockable.
Worked example
A paint-spray booth is Class I Division 1. A general-purpose junction box cannot be used. The installer must use a listed explosionproof box, seal the conduit within 18 in of the box, and bond all metal parts. The inspector rejects a standard NEMA 1 enclosure even though it is inside the booth area.
Traps
Treating Division 2 as interchangeable with Division 1; using NM cable in a hazardous location; omitting pool bonding because the water is “not metal”; and missing the motor disconnect’s “within sight” requirement.