Lesson 1Cabling basics: power cables, multi-core control cables, shielded signal cables, and conduit vs tray selectionThis part introduces the basics of cabling for power, control, and signals. It covers conductor sizing, insulation types, shielded cables, and deciding between conduit and tray, paying attention to segregation, bending radius, and EMC performance in local conditions.
Conductor sizing and voltage dropPower vs control cable constructionShielded signal cable and groundingSegregation of power and signal routesConduit, tray, and flexible conduit useLesson 2Terminal block selection and distribution: feed-through, fuseable, ground, and shield termination blocksHere, we focus on picking terminal blocks and how to distribute them, including feed-through, fuse, ground, and shield terminals. We discuss current and voltage ratings, jumpering, labeling, and layout for safe, easy-to-maintain industrial control panels in Eritrea.
Feed-through terminal applicationsFuse and disconnect terminal blocksGrounding and PE terminal designShield termination and EMC controlJumpering, labeling, and groupingLesson 3Field device choices: photoelectric sensor types, cable gland and connector selection, appropriate ingress protection (IP) ratingsThis section deals with selecting field devices and their connections, like photoelectric sensor types, cable glands, connectors, and IP ratings. We emphasize the environment, mounting, wiring methods, and mechanical protection for reliable work in Eritrean industries.
Diffuse, retroreflective, and through-beam sensorsPNP vs NPN and 2-wire vs 3-wire sensorsCable gland sizing and strain reliefM12 and other industrial connector typesIngress protection (IP) and NEMA ratingsLesson 4Protection devices: MCCB, MCB, fuses, motor protection circuit breakers, and overload relaysWe cover protection devices for feeders and motors, such as MCCBs, MCBs, fuses, motor protection breakers, and overload relays. The focus is on interrupting capacity, trip curves, coordination, and protecting cables and equipment in local power systems.
MCB and MCCB ratings and trip curvesFuse types, classes, and applicationsMotor protection circuit breakers (MPCBs)Thermal and electronic overload relaysSelective and backup coordination basicsLesson 5VFD selection criteria: voltage rating, current rating, overload capacity, braking, EMC filtersThis part explains selecting VFDs based on voltage and current rating, overload capacity, braking options, and EMC filters. It includes matching to motor data, ambient conditions, cable length, and needed control interfaces and protections for Eritrean use.
Matching VFD voltage and currentNormal and heavy duty overload classesDynamic braking and braking resistorsInput and output EMC filter optionsCable length, dV/dt, and motor stressLesson 6Three-phase supply types and selection (208V/230V/400V/480V) and impact on motor/VFD sizingWe explain common three-phase supply systems like 208, 230, 400, 480 V, their frequency, grounding, and short-circuit levels. See how these affect motor and VFD selection, insulation ratings, and panel component clearances in Eritrea.
Wye vs delta and grounded systems208 V vs 230 V vs 400 V vs 480 V useFrequency and motor speed implicationsShort-circuit level and SCCR impactVoltage tolerance and derating rulesLesson 7Motor selection and thermal ratings for 5–10 HP motors including service factors and nameplate interpretationThis section covers choosing 5–10 HP motors, focusing on voltage, enclosure, and duty. We interpret nameplate data, thermal classes, service factor, and how these guide overload settings, starting methods, and coordination with drives.
Reading motor nameplate dataInsulation and temperature rise classesService factor and allowable overloadEnclosure types and cooling methodsDuty cycle and starting requirementsLesson 8Control power supplies: AC vs DC control, sizing 24VDC supplies, redundancy and filteringWe compare AC and DC control power, explain sizing 24 VDC supplies for steady and inrush loads, and cover redundancy, buffering, and filtering to boost reliability and noise resistance in industrial panels across Eritrea.
AC vs DC control power advantagesCalculating 24 VDC load and inrushDerating power supplies for temperatureRedundant and parallel supply schemesEMI filtering and surge protectionLesson 9Auxiliary devices: contactors, control relays, timers, pushbuttons, pilot devices, stack light modulesLearn to choose auxiliary devices like contactors, control relays, timers, pushbuttons, pilot lights, and stack lights. Focus on coil ratings, utilization categories, mechanical life, and fit for control schemes in local applications.
Contactor utilization categories and coilsControl relays and interposing relaysOn-delay, off-delay, and multifunction timersPushbuttons, selector switches, pilot lightsStack lights, buzzers, and signaling levels
