Special Occupancies, Locations, and Equipment
What you must understand
This domain covers hazardous (classified) locations, health care facilities, places of assembly, commercial garages, agricultural buildings, and wet/damp locations. Know the class, division, and zone system for hazardous locations and the wiring methods permitted in each. Understand the requirements for patient care areas, emergency systems, and the special rules for pools, spas, and fountains. Alaska conditions also make cold-weather and wet-location installation practices relevant.
Traps
Questions often test the distinction between Class I (flammable gases), Class II (combustible dust), and Class III (fibers), and the division concept (normal versus abnormal conditions). Another trap is assuming ordinary wiring methods are acceptable in hazardous locations. Health care questions frequently test the redundant grounding requirements and the use of hospital-grade receptacles. Watch for questions about the boundary distances for pools and the GFCI requirements near water.
Rule of thumb and worked example
Rule of thumb: in a Class I, Division 1 location, only approved explosion-proof or intrinsically safe equipment and rigid metal conduit or equivalent wiring methods are permitted. Example: a gasoline dispensing area within the defined classified zone requires seal-offs at the boundary and explosion-proof fittings; ordinary EMT would not be acceptable. Match the wiring method to the classification before selecting any other answer.