Chapter 5 of 514% of exam
Code Administration, Working Space, and Electrical Safety
Working Space (110.26)
Minimum working depth for 0-150 V, Condition 1, is 3 ft in front of the equipment.
Minimum working width is 30 in or the width of the equipment, whichever is greater.
Minimum headroom is 6.5 ft, and the dedicated space extends 6 ft above the equipment.
Equipment rated 1,200 A or more and over 6 ft wide requires two egress paths.
Terminations and Fault Marking
Terminations rated 100 A or less use the 60 C column unless listed otherwise.
Terminations rated over 100 A use the 75 C column unless listed and marked for more.
Service equipment must be field marked with the maximum available fault current and its date.
Code Administration and Scope
The authority having jurisdiction interprets and enforces the NEC and grants special permission.
The NEC does not cover utility-owned generation, transmission, or distribution under exclusive utility control.
Rough-in inspections occur before wiring is concealed; final inspection precedes energizing or occupancy.
Electrical Safety and Arc Flash
NFPA 70E governs safe work practices, shock protection, and arc-flash boundaries.
The preferred practice is to establish an electrically safe work condition (de-energize, lock out, verify).
Cal/OSHA lockout/tagout isolates hazardous energy during servicing.
Equipment likely to be serviced energized must carry an arc-flash warning label per 110.16.
Test your knowledge
Practice questions on Code Administration, Working Space, and Electrical Safety
Last updated: July 2026