CEI Cheat Sheet 2026

The 30 highest-yield CEI facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. The National Electrical Safety Code (NESC) primarily applies to which type of electrical installation? → Utility supply lines and communication systems
2. Which of the following best describes a key competency required for commercial & industrial systems in CEI practice? → Strong analytical skills combined with effective communication and ethical judgment
3. An AEx marking on equipment indicates it has been certified under which standard? → ATEX European directive
4. An inspector finds recessed lighting fixtures in direct contact with attic insulation. The fixtures are marked 'IC'. What does this marking indicate? → The fixture is rated for insulation contact and can be covered by insulation
5. During inspection, a motor nameplate indicates 'SF 1.15.' What does this service factor mean? → The motor is rated for continuous duty at 115% of its nameplate horsepower
6. Which NEC section addresses the requirement that service-entrance conductors must be protected against physical damage? → NEC 230.50
7. A commercial wind energy system uses a guy-wire supported tower. What grounding requirement applies to the guy wires under NEC 694.40? → Metallic guy wires must be bonded to the tower's grounding electrode system
8. Which type of bushing is required when rigid metal conduit enters a cabinet or enclosure without a threaded hub? → Insulating bushing or insulated fitting
9. Which device automatically disconnects power when arc-fault conditions are detected? → AFCI breaker
10. When a generator serves both emergency and legally required standby loads, the two systems must: → Have separate transfer switches unless the generator has sufficient capacity
11. What does NEC 600.6 require for signs and outline lighting in commercial buildings regarding disconnecting means? → An externally operable switch or circuit breaker within sight of the sign
12. Which inspection method is most appropriate for verifying conductor insulation integrity in an existing installation? → Megohmmeter (insulation resistance) testing
13. Under NEC 701.12, legally required standby power must be available within how many seconds of normal power failure? → 60 seconds
14. In a commercial building, what is the minimum burial depth for rigid metal conduit (RMC) installed under a parking lot? → 12 in
15. Which authority is responsible for classifying which loads belong on an emergency system versus a legally required standby system? → The authority having jurisdiction (AHJ)
16. What is the maximum voltage permitted for a PV system installed on a one- or two-family dwelling under NEC 690.7? → 600V
17. What is the maximum distance a receptacle outlet can be placed from a doorway along a wall space in a residential living room per NEC 210.52(A)? → 6 feet
18. Which NEC section requires ground-fault circuit-interrupter (GFCI) protection for 125V, 15A and 20A receptacles in commercial bathrooms? → 210.8(B)
19. When inspecting a CT (current transformer) metering installation, why are instrument transformers used? → To reduce high current to a manageable level for meter measurement
20. Under NEC 700.10, emergency system wiring must be kept entirely independent of other wiring EXCEPT when: → Both circuits are in separate raceways within the same enclosure
21. Which safety gear is essential during inspections? → Gloves and safety glasses
22. Which of the following best describes a key competency required for renewable energy system inspection in CEI practice? → Strong analytical skills combined with effective communication and ethical judgment
23. What is the maximum distance allowed between a motor disconnect and the motor controller, according to NEC 430.102? → Within sight from the controller
24. A separately derived system's grounding electrode conductor must be connected at which point? → At the source of the separately derived system
25. Per NEC 215.2(A)(1), feeder conductor ampacity must be not less than which of the following? → 100% of non-continuous load plus 125% of continuous load
26. When inspecting a commercial kitchen, which NEC section would a CEI reference to verify GFCI protection requirements for receptacles? → 210.8(B)
27. Under NEC 230.79, what is the minimum ampere rating required for the service disconnecting means of a single-family dwelling? → 100 amperes
28. Bonding of metal gas piping is required when the piping system could become energized. The bond must be connected to: → The equipment grounding conductor or grounded service conductor
29. Which statement best describes a 'separate service' as an emergency source under NEC 700.12(D)? → A service from a separate utility or network protector on a different utility grid section
30. Which Group classification applies to acetylene in hazardous location wiring? → Group A