Licensed Electrical Inspector (LEI) G Class Theory study guide
Licensed Electrical Inspector (LEI) G Class Theory · Work through your exam, one topic at a time.
The Licensed Electrical Inspector (LEI) G Class Theory credential is a professional certification for electricians, engineers, and code officials who inspect electrical installations for compliance with adopted codes and standards. It signals that the holder understands the principles behind inspection decisions, not just memorized rules. The Licensed Electrical Inspector (LEI) G Class Theory study guide has 8 sections and about 2,303 words.
01Electrical Theory, Circuits, and Calculations
A candidate must be fluent with Ohm's law and the power relationships that follow from it, series and parallel network reduction, AC impedance (resistance, inductive reactance, capacitive reactance, and their phasor combination), three-phase relationships, power factor, and the difference between real, reactive, and apparent power. Voltage drop, conductor ampacity derating, and box/conduit fill calculations recur in inspection scenarios, so the arithmetic must be automatic.
302 words, about 2 min02Wiring Methods, Materials, and Installation Standards
Understand the recognized wiring methods and where each is permitted: nonmetallic-sheathed cable, armored cable, metal-clad cable, rigid and intermediate metal conduit, electrical metallic tubing, PVC conduit, liquidtight flexible conduit, and wireways. Know conductor insulation types and temperature ratings, termination temperature limits, support and securing intervals, bending radius, box fill, conduit fill, and the rules for raceways in wet, corrosive, or hazardous locations.
301 words, about 2 min03Grounding, Bonding, and Overcurrent Protection
Distinguish system grounding (intentionally connecting a circuit conductor to earth) from equipment grounding (bonding non-current-carrying metal parts to provide a low-impedance fault path) and from bonding (electrically joining metal parts to ensure they remain at the same potential). Know the grounded conductor versus the grounding conductor, the role of the main bonding jumper, grounding electrode systems and electrodes, and the requirement that equipment grounding conductors be sized relative to the overcurrent device.
305 words, about 2 min04Electrical Codes, Regulations, and Permit Procedures
Know the hierarchy of authority: statute, adopted regulation, the adopted electrical code edition, local amendments, and approved standards referenced by the code. Understand the permit process, who may apply, when a permit is required, what work is exempt, plan review triggers, inspection request procedures, certificate of occupancy or approval, and the rules for temporary and emergency work.
293 words, about 1 min05Inspection Procedures, Plan Review, and Documentation
A defensible inspection is systematic: verify the approved plans, confirm the permit scope, perform a visual inspection, conduct required tests (continuity of the equipment grounding conductor, polarity, ground-fault circuit-interrupter trip tests, insulation resistance where required), and record results. Plan review checks load calculations, service and feeder sizing, conductor and overcurrent device coordination, working clearances, and egress and equipment labeling.
265 words, about 1 min06Safety, Hazard Identification, and Risk Assessment
Understand arc flash and shock hazards, approach boundaries, lockout/tagout, personal protective equipment selection, test-before-touch, and the use of properly rated test instruments. Identify common hazards: exposed live parts, missing enclosures, damaged insulation, improper temporary wiring, blocked working space, inadequate illumination, and unguarded openings in equipment.
277 words, about 1 min07Special Occupancies, Equipment, and Systems
Know the classification approach for hazardous locations: Class I gases and vapors, Class II combustible dusts, Class III fibers and flyings, with Division or Zone systems and group designations. Understand the protection concepts: explosionproof, dust-ignitionproof, purged and pressurized, intrinsically safe, and increased safety.
292 words, about 1 min08Professional Ethics, Liability, and Inspector Conduct
An inspector exercises delegated public authority and owes duties to the jurisdiction, the public, and the regulated party. Core obligations: competence within one's scope, impartiality, confidentiality of proprietary information, avoidance of conflicts of interest, honest reporting, and consistent application of the adopted code.
268 words, about 1 min