Lesson 1NEC 2020+ requirements for services and service disconnects (Articles 230, 230.70)This lesson explores NEC service requirements, including service entrance conductors, disconnect locations, grouping, labelling, and emergency access, with focus on 230.70 rules and typical violations observed in commercial buildings in Botswana.
Service entrance conductors and routingService disconnect location and accessibilityNumber, grouping, and identification of disconnectsService equipment working space and clearancesLabelling, signage, and utility coordinationLesson 2Wiring methods and installation requirements for conduit, cable, flexible cords (Articles 330, 340, 348, 400)This lesson examines NEC rules for MC, UF, flexible metal conduit, and flexible cords in commercial projects in Botswana, including permitted uses, securing, supporting, fittings, terminations, and common inspection challenges for these methods.
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)This lesson covers grounding and bonding basics under NEC 250, including objectives, permitted methods, and essential rules for commercial services, feeders, and separately derived systems, emphasising safe fault clearing and touch voltage management in Botswanan installations.
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, equipmentThis lesson clarifies NEC definitions for premises wiring, services, feeders, branch circuits, and equipment, aiding inspectors in identifying system components, applying scope limits, and differentiating utility equipment from customer-owned wiring in Botswana.
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 sizingThis lesson delves into equipment grounding conductors, grounding electrode systems, and bonding jumpers, explaining sizing via NEC tables, material selection, terminations, and inspection checks for continuity and fault current paths in local contexts.
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)This lesson outlines NEC branch circuit rules for receptacles in commercial areas in Botswana, covering ratings, load calculations, multiwire circuits, required locations, and checks for overloading and improper neutral sharing.
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)This lesson addresses NEC rules for damp, wet, and dry locations, outdoor equipment, and protections against corrosion and mechanical damage, guiding inspectors on enclosure ratings, fittings, sealing, and physical safeguards for raceways and cables in Botswana.
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)This lesson explains NEC rules for emergency systems, legally required standby, optional standby, and interconnected power sources in Botswana, including transfer equipment, signage, disconnects, and inspection priorities for Articles 700–705 and 750.
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 tablesThis lesson illustrates the NEC structure, from chapters and articles to parts, sections, and tables, training inspectors to locate relevant rules, exceptions, and annexes for commercial and light industrial setups in Botswana.
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)This lesson covers NEC overcurrent protection and conductor ampacity rules, using Tables 240.6 and 310.16, adjustment and correction factors, tap rules, and coordination for feeders and branch circuits in Botswanan commercial and light industrial applications.
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
