Lesson 1NEC 2020+ requirements for services and service disconnects (Articles 230, 230.70)This lesson details NEC service rules, covering service entrance conductors, disconnect locations, grouping, labelling, and emergency access, highlighting 230.70 provisions and frequent issues spotted in commercial buildings during inspections.
Service entrance conductors and routingService disconnect location and accessibilityNumber, grouping, and identification of disconnectsService equipment working space and clearancesLabeling, signage, and utility coordinationLesson 2Wiring methods and installation requirements for conduit, cable, flexible cords (Articles 330, 340, 348, 400)Review NEC guidelines for MC, UF, flexible metal conduit, and flexible cords in commercial jobs, including allowed uses, securing, supporting, fittings, terminations, and typical inspection pitfalls.
Uses and limits of MC and UF cablesFlexible metal conduit routing and supportProtection at terminations and fittingsFlexible cord types and permitted usesBox fill, derating, and cable assembliesLesson 3Grounding and bonding fundamentals and NEC requirements (Articles 250)Explore grounding and bonding basics under NEC 250, covering goals, approved methods, and main rules for commercial services, feeders, and derived systems, stressing safe fault clearing and touch voltage management.
Objectives of grounding and bonding systemsGrounding of services and main disconnectsGrounding separately derived systemsBonding of metal piping and structural steelGrounding and bonding documentation reviewLesson 4Key definitions and scope: premises wiring, services, feeders, branch circuits, equipmentClarify NEC terms for premises wiring, services, feeders, branch circuits, and equipment to help inspectors properly identify components, apply scope boundaries, and separate utility gear from customer wiring.
Premises wiring versus utility supplyService conductors and service equipmentFeeders and feeder tap conductorsBranch circuits and utilization equipmentSeparately derived systems and transformersLesson 5Equipment grounding conductors, electrode systems, and bonding jumpers — details and sizingFocus on equipment grounding conductors, electrode systems, and bonding jumpers, explaining sizing via NEC tables, materials, terminations, and checks for continuity and fault paths during inspections.
Grounding electrode conductors and electrodesEquipment grounding conductor types and sizingMain and system bonding jumper functionsBonding of raceways, enclosures, and fittingsTesting continuity of grounding pathsLesson 6Branch circuits and receptacles: ratings, allowed loads, multiwire branch circuits (Article 210)Cover NEC rules for branch circuits and receptacles in commercial areas, including ratings, load calcs, multiwire setups, required outlet positions, and checks for overloads or neutral sharing issues.
General branch circuit ratings and typesReceptacle placement in commercial areasContinuous and noncontinuous load sizingMultiwire branch circuits and handle tiesGFCI and AFCI protection for receptaclesLesson 7Special location rules: damp, wet, and dry locations; outdoor equipment; corrosion and mechanical protection (Articles 110, 300, 314)Address NEC provisions for damp, wet, dry spots, outdoor gear, corrosion, and mechanical safeguards, guiding inspectors on enclosure types, fittings, sealing, and protection for raceways and cables.
Classifying damp, wet, and dry locationsEnclosure and raceway ratings for outdoorsCorrosion protection for metallic systemsMechanical protection for cables and conduitsSealing fittings and condensation controlLesson 8NEC requirements for emergency systems, signage, and disconnecting means for equipment (Articles 700–705, 750)Explain NEC rules for emergency, standby systems, and power sources, covering transfer gear, signage, disconnects, and inspection priorities for Articles 700-705 and 750 in commercial setups.
Emergency versus standby system categoriesTransfer switches and source interconnectionsRequired signage and identification markingsDisconnecting means for generators and invertersEmergency circuit wiring and separation rulesLesson 9Structure and organization of the National Electrical Code (NEC) — how to find applicable articles and tablesLearn NEC layout from chapters to tables, training inspectors to swiftly find relevant rules, exceptions, and annexes for commercial and light industrial electrical work.
NEC chapters, articles, and parts layoutMandatory rules, permissive rules, and notesFinding applicable tables and calculation rulesUsing annexes, fine print notes, and indexesCross-referencing articles for complex systemsLesson 10Overcurrent protection and conductor ampacity: NEC tables, adjustment and correction factors (Articles 240, 310)Detail NEC overcurrent and ampacity rules using Tables 240.6 and 310.16, adjustments, corrections, taps, and coordination for commercial feeders and branches.
Standard overcurrent device ratings and typesSelecting OCPD for feeders and branch circuitsUsing ampacity tables and temperature ratingsAdjustment and correction factor applicationTap conductors and transformer secondary rules