General Electrical Knowledge and Code Administration
Code structure and administration
The Michigan journeyman exam tests both electrical knowledge and the administrative rules that govern electrical work. Start with NEC Article 90 (scope) and Article 100 (definitions); nearly every calculation question depends on a defined term such as service point, feeder, branch circuit, continuous load, or qualified person. Chapters 1 through 4 provide general requirements, wiring and protection, wiring methods, and equipment. Chapters 5 through 7 cover special occupancies, special equipment, and special conditions, while Chapter 8 covers communications and Chapter 9 contains tables and annexes.
Michigan adopts the NEC through statute and administrative rule, with local amendments and permitting/inspection procedures. Know that permits, inspections, and licensing are part of code compliance, not optional paperwork; work without a permit can fail inspection even when the installation is electrically sound.
Traps and a worked example
Questions often turn on mandatory language: “shall” is mandatory, “should” is advisory, and fine print notes are explanatory. Watch exceptions, because they change the general rule. Do not assume the highest insulation temperature column controls ampacity: conductor ampacity is limited by termination temperature ratings under 110.14(C). For a 100 A feeder with 75°C terminations and 75°C THWN copper, use the 75°C column: 3 AWG copper is good for 100 A. If terminations were only 60°C, 3 AWG would be limited to 85 A and a larger conductor would be required. Rule of thumb: determine the weakest link-termination, conductor insulation, or conditions of use-before selecting a size.