Aprender por año
Pick the year you are in. Each one lists what apprentices usually meet in that period — plain lessons, interactive diagrams you can switch and trace, and drills that mark you on the spot. 128 pages so far, all free. The order is a study order, not your province’s syllabus: check your own course outline and code book for what your exam covers.
Aprendiz de primer año
Staying safe, the tools, what voltage, current and resistance actually are, Ohm’s law, series and parallel, prints, boxes and devices, grounding and bonding, the circuits in a house, and your meter.
- Lesson 15 min
Safety, PPE and arc-flash awareness
How electricity hurts people, what shock and arc flash are, the PPE that goes with the job, and why you test before you touch.
New lesson - Lesson 12 min
Hand tools and testers
The kit a first-year carries, what each tool is for, and the difference between a non-contact tester, a two-pole tester and a meter.
New lesson - Lesson 15 min
What electricity is
Voltage, current, resistance and power in plain words — the water-hose picture, where it helps and where it lies.
New lesson - Lesson 18 min
Ley de Ohm y potencia
V = I × R and P = V × I, the wheel that joins them, and five worked examples with real loads.
New lesson - Lesson 15 min
Series circuits
One path: the current is the same everywhere, the voltages add up, and one open stops the lot.
New lesson - Lesson 15 min
Parallel circuits
Many paths: the voltage is the same across every branch, the currents add, and the total resistance drops below the smallest branch.
New lesson - Lesson 18 min
Combination circuits
Series and parallel in one circuit — how to reduce it step by step and work back out to every current and voltage.
New lesson - Lesson 14 min
Conductors and insulation
Why copper and aluminium, what makes a conductor’s resistance, what insulation does, and where the ampacity tables come in.
New lesson - Lesson 15 min
Reading prints and symbols
Floor plans, legends, symbols, home runs and schedules — how to find your work on an electrical drawing.
New lesson - Lesson 15 min
Boxes, devices and terminations
Stripping, the screw terminal loop, back-wire clamps, wire connectors, torque and the habits that stop a joint from burning up.
New lesson - Lesson 16 min
Grounding and bonding
Two different jobs that people mix up: connecting to earth, and tying metal together so a fault trips the breaker.
New lesson - Lesson 18 min
Basic residential circuits
Receptacle and lighting circuits, switch legs, and what GFCI and AFCI protection actually watch for.
New lesson - Lesson 15 min
Trade math refresher
Fractions, decimals, percent, metric and imperial, square roots and powers of ten — the arithmetic every other lesson leans on.
New lesson - Lesson 16 min
Using your meter
Continuity, voltage and current: where the leads go, what the reading means, and the three-point test before you trust a dead reading.
New lesson - Drill 12 min
First-year review quiz
Fifteen questions across the whole first year. Take it cold, then go back to whatever it catches.
New lesson - Lesson 5 min
Start here: the apprentice path
Five stages in order — read, try, drill — with your progress kept in your browser.
- Lesson 8 min
Vivo, neutro, tierra
The three conductors by the job each does, and what a fault does to each.
- Drill 3 min
Prueba de cinta métrica
Read a tape to the nearest sixteenth, to a streak of ten.
- Lesson 8 min
Las fracciones en una cinta
Halves, quarters, eighths, sixteenths — and adding them without a calculator.
- Lesson 6 min
Leer una cinta rápido
Count back from the nearest big mark instead of up from the inch.
- Drill 3 min
Fraction / decimal drill
Fractions of an inch to decimals and back, self-marking.
- Drill 4 min
Práctica de la ley de Ohm
Find V, I, R or P at three levels, marked on the spot.
- Drill 5 min
Series / parallel practice
Total resistance, string current and the drop across one resistor.
- Interactive 6 min
Series vs parallel lighting
Pull a lamp from each circuit and see why houses are wired in parallel.
- Interactive 6 min
Single-pole switch wiring
The simplest switched light, traced conductor by conductor.
- Interactive 6 min
Switch loop wiring
Power at the light, a loop down to the switch — and which wire is which.
- Interactive 6 min
Duplex receptacle wiring
Brass, silver and the tab — and why an empty outlet is still live.
- Interactive 8 min
3-way switch wiring
Two switches, one light: toggle each and trace the travellers.
- Lesson 10 min
Cómo leer un diagrama esquemático
Symbols, lines and the conventions every drawing assumes you know.
- Lesson 5 min
Símbolos eléctricos
The common schematic symbols, drawn and grouped by category.
- Lesson 8 min
Seguridad del medidor y categorías CAT
What the category on your meter means and the live-dead-live habit.
- Lesson 10 min
Cómo usar un multímetro
Volts, continuity and amps — which jack, which setting, and what lies to you.
- Lesson 8 min
Lockout / tagout
Your lock, your key, and proving it dead before a hand goes in.
- Lesson 7 min
Dispositivos de cableado comunes
What the screws and markings on switches and receptacles are telling you.
- Lesson 5 min
Índice de accesorios
Connectors, couplings and boxes by name, so you grab the right one.
- Drill 3 min
Conversion drill
Inches to millimetres and feet to metres, both ways.
- Lesson 6 min
Metric and imperial
Converting in your head: the anchors worth memorising.
Aprendiz de segundo año
Alternating current: the sine wave, inductance and capacitance, reactance and impedance, power factor, transformers, three-phase, motors, lighting controls, services, wiring methods, voltage drop and a troubleshooting method.
- Lesson 16 min
AC fundamentals
The sine wave, frequency, peak and peak-to-peak, and why a 120 V supply actually swings to about 170 V.
New lesson - Lesson 15 min
Inductancia
A coil fights any change in its own current: what that looks like on DC, on AC, and when you open a switch on one.
New lesson - Lesson 15 min
Capacitancia
Two plates and a gap that store charge: charging, the time constant, and why a capacitor can bite after the power is off.
New lesson - Lesson 18 min
Reactance and impedance
XL = 2πfL, XC = 1/(2πfC), and how resistance and reactance combine into impedance at right angles.
New lesson - Lesson 16 min
Power factor and the power triangle
Watts, VARs and volt-amps, what a lagging power factor costs, and how capacitors correct it.
New lesson - Lesson 18 min
Single-phase transformers
Turns ratio, full-load current from kVA, additive and subtractive polarity, and series or parallel windings for 120/240.
New lesson - Lesson 18 min
Intro to three-phase
Why three phases, 120° apart; line and phase values in wye and delta; where √3 comes from.
New lesson - Lesson 17 min
Magnetism and motors
Fields, electromagnets, force on a conductor, the rotating field, synchronous speed and slip.
New lesson - Lesson 15 min
Lighting circuits and controls
Switching from one, two and three places, dimmers, occupancy sensors, photocells, contactors and low-voltage control.
New lesson - Lesson 16 min
Services and panels
From the utility to the branch circuit: the service, the meter, the main disconnect, the panel, and where neutral and ground meet.
New lesson - Lesson 14 min
Cables and raceways
NM, armoured and TECK-style cable, EMT, rigid, PVC and flex — what each wiring method is and why you would pick it.
New lesson - Lesson 16 min
Caída de tensión
Why long runs lose volts, the out-and-back formula, and working it with the resistance from your own code book.
New lesson - Lesson 15 min
A troubleshooting method
Symptom, half-split, test, fix, verify — a method you can use on any circuit instead of swapping parts.
New lesson - Drill 12 min
Second-year review quiz
Fifteen questions across AC, transformers, three-phase, motors and troubleshooting.
New lesson - Interactive 8 min
4-way switch wiring
Three or more switch points: what the 4-way does to the travellers.
- Interactive 7 min
Split receptacle wiring
Break the tab, switch half the outlet, and keep the neutral right.
- Interactive 7 min
Cableado de un GFCI
Line versus load, and what a trip actually disconnects.
- Interactive 7 min
240 V receptacle wiring
Two hots, no neutral (or one) — and how a two-pole breaker feeds it.
- Interactive 6 min
Photocell wiring
A dusk-to-dawn switch in the circuit, traced.
- Interactive 6 min
Occupancy sensor wiring
Sensors that need a neutral, and ones that do not.
- Lesson 8 min
Leer el directorio de un tablero
Odd left, even right, and how a two-pole breaker spans.
- Lesson 10 min
Lo básico del doblado de conduit
Stub-ups, offsets and saddles — what the marks on the bender mean.
- Drill 4 min
Offset math practice
Distance between bends from the rise and the angle.
- Lesson 8 min
Triángulos rectángulos en la obra
Pythagoras and the 3-4-5 check, where they actually get used.
- Lesson 6 min
Los porcentajes en el oficio
Percent of, percent change and the working behind a derating.
- Drill 5 min
Práctica de matemáticas del oficio
Mixed practice plus a printable 20-question worksheet.
- Lesson 8 min
Lo básico de baja tensión y datos
Cable categories, terminations and keeping data away from power.
- Lesson 5 min
Unión equipotencial contra puesta a tierra
Two words used as one, and the different jobs they do.
- Lesson 5 min
AFCI contra GFCI
Shock protection versus fire protection, side by side.
- Lesson 4 min
Ampacidad
What the word means and why it comes from your code book, not a chart online.
- Tool 3 min
Bending multipliers sheet
Multipliers and shrink by angle, from the trigonometry — printable.
Tercer año
Three-phase in depth, transformer banks, AC motors and how they start, your first PLC, protection and grounding as systems, and the commercial jobsite: wiring methods, prints and fire alarm.
- Lesson 14 min
Wye and delta: line vs phase
The two ways three windings are joined, and the √3 that separates line from phase voltage and current.
New lesson - Lesson 13 min
Unbalanced loads and neutral current
Why a balanced wye neutral carries nothing, what it carries when the loads are uneven, and the harmonics that break the rule.
New lesson - Lesson 14 min
Three-phase power and power factor
kW, kVA and kVAR on a three-phase load: the power triangle, the √3 formula and what a poor power factor costs.
New lesson - Lesson 15 min
Three-phase transformer connections
Delta-wye, wye-wye, delta-delta and wye-delta: what each gives you on the secondary and where you meet it.
New lesson - Lesson 14 min
Polarity, phase shift and open delta
Additive and subtractive polarity, the 30° shift through a delta-wye, and running a bank on two cans.
New lesson - Lesson 15 min
How an AC induction motor works
The rotating field, synchronous speed, slip, and reading the nameplate numbers that come out of them.
New lesson - Lesson 13 min
Motor starting methods
Across-the-line, primary resistor, autotransformer, wye-delta, soft starter and drive — what each trades away.
New lesson - Lesson 16 min
Intro to PLCs: from relays to ladder logic
Inputs, outputs, the scan cycle, and how a hard-wired start/stop becomes three rungs of ladder logic.
New lesson - Lesson 14 min
Overcurrent protection and coordination
Overload versus short circuit, reading a time-current curve, and what "selective coordination" is trying to do.
New lesson - Lesson 15 min
Grounding and bonding as a system
System grounding, equipment bonding, the fault return path and separately derived systems, end to end.
New lesson - Lesson 12 min
Commercial wiring methods
EMT, rigid, flex, cable tray, armoured cable and busway — what each is good at and the questions to ask of the book.
New lesson - Lesson 14 min
Reading commercial and industrial prints
The drawing set, single-lines, risers, panel and luminaire schedules, and finding your way around a sheet.
New lesson - Lesson 13 min
Fire alarm basics
Initiating and notification devices, supervision and end-of-line devices, conventional versus addressable.
New lesson - Drill 20 min
Third-year review quiz
Every third-year question in one place, mixed, with explanations. Filter to a topic you are weak on.
New lesson - Lesson 10 min
Lo básico de los transformadores
Turns ratio, primary and secondary, and what the nameplate tells you.
- Lesson 10 min
Leer la placa de datos de un motor
Every field on the plate, and which ones you need for the job.
- Lesson 5 min
Factor de potencia
Real versus apparent power, in plain words.
- Lesson 5 min
Estrella y delta
The two three-phase connections and the voltages each gives you.
- Tool 3 min
Single and three phase formulas
Power, current and the √3 — a printable sheet.
- Interactive 7 min
Contactor wiring
The coil, the power contacts and the control circuit, traced.
- Interactive 7 min
Estación de arranque/paro de un motor
The classic three-wire station and its seal-in.
- Lesson 15 min
Curso de control de motores
Twelve interactive lessons from ladder diagrams to fault finding.
- Interactive 10 min
Reading a ladder diagram
Rails, rungs, coils and contacts — run the first circuit.
- Interactive 10 min
Two-wire vs three-wire control
Maintained versus momentary, and what happens after a power cut.
- Interactive 10 min
Start/stop and the seal-in
The holding contact that keeps a motor running after you let go.
- Interactive 10 min
The overload relay
What trips it, what it opens, and how it resets.
- Interactive 10 min
More than one station
Starts in parallel, stops in series — prove it in the lab.
- Interactive 10 min
Jogging
Inching a motor without letting it seal in.
- Interactive 12 min
Forward / reverse
Two contactors, swapped phases and the interlocks that stop a short.
Cuarto año
Drives, power quality, industrial troubleshooting and 4–20 mA loops; emergency power and hazardous locations as ideas; the service and fault-current arithmetic; relaying; and how to walk into the exam ready.
- Lesson 15 min
How a VFD works
Rectifier, DC bus, inverter and PWM: how a drive makes variable frequency, and why volts-per-hertz matters.
New lesson - Lesson 16 min
VFD parameters and troubleshooting
The nameplate parameters, accel/decel, the common trips (overvoltage, overcurrent, ground fault) and what causes them.
New lesson - Lesson 15 min
Power quality and harmonics
Sags, swells, transients and harmonics: where they come from, what they do to neutrals and transformers, and how to see them.
New lesson - Lesson 15 min
Troubleshooting industrial controls
Half-splitting a control circuit, reading voltage across open contacts, and the PLC I/O lights as a meter.
New lesson - Lesson 15 min
Instrumentation and the 4–20 mA loop
Why a current loop, live zero, two-wire transmitters, scaling, and measuring a loop without breaking it.
New lesson - Lesson 13 min
Emergency and standby power
Generators, transfer switches, UPS and unit equipment — what each is for and why the circuits are kept apart.
New lesson - Lesson 14 min
Hazardous locations: the ideas
Why a spark matters, how locations are classified (Class/Division and Zones), and the protection concepts behind the equipment.
New lesson - Lesson 16 min
Services and the load calculation method
Connected load, demand, and the steps of a dwelling or commercial calculation — with every table value your own.
New lesson - Lesson 14 min
Available fault current
Where short-circuit current comes from, the infinite-bus estimate from %Z, and why it sets the equipment rating question.
New lesson - Lesson 14 min
Protective relaying concepts
CTs and PTs, overcurrent, differential and ground-fault relays, device numbers, and what a relay actually trips.
New lesson - Lesson 13 min
Finding it in the code book
How the book is built, the index as a skill, reading a rule reference down to its item, and the tabs that save minutes.
New lesson - Lesson 12 min
Exam prep strategy
A study plan backed off from exam day, timing on the day, the calculation habit, and how to use practice questions.
New lesson - Drill 20 min
Fourth-year review quiz
Every fourth-year question, mixed, with explanations — then widen it to the whole program.
New lesson - Interactive 12 min
On-delay and off-delay timers
TON and TOF contacts, timed out in the lab.
- Interactive 12 min
Sequence control
Motor 2 cannot start until motor 1 runs — and stops with it.
- Interactive 10 min
Hand-Off-Auto
A selector switch that hands control to a pilot device.
- Interactive 12 min
Wye-delta starting
Start in wye, run in delta, with the timer and interlocks.
- Interactive 15 min
Motor control troubleshooting
A hidden fault in a live ladder — find the part with the meter.
Repaso para oficiales
Rusty on something? Short refreshers for the things you do not touch every week — three-phase math, transformer banks, motors, drives, PLCs, load calcs — plus a practice exam across the whole program.
- Drill 30 min
Journeyman practice exam
Over a hundred questions across the program with explanations. Filter by topic or year; your progress is kept.
New lesson - Lesson 9 min
Rusty on three-phase math?
Line and phase, the √3, power and current in both directions — the whole kit on one page with worked checks.
New lesson - Lesson 9 min
Rusty on transformer connections?
The four bank connections, what each secondary gives you, and the checks before you energize.
New lesson - Lesson 10 min
Motor troubleshooting flowcharts
Will not start, trips on start, runs hot, noisy — a flowchart for each, from the supply to the shaft.
New lesson - Lesson 8 min
The troubleshooting method
Symptom, known-good, half-split, prove it, fix it, prove the fix — the loop every good troubleshooter runs.
New lesson - Lesson 8 min
Meter safety re-cert refresher
CAT ratings, test-before-touch, live-dead-live, leads and fuses — the things a meter re-cert checks.
New lesson - Lesson 9 min
Rusty on PLCs?
The scan, XIC and XIO, the NC stop-button trap, latches, timers and counters, and forcing — safely.
New lesson - Lesson 9 min
Rusty on VFDs?
The parameters you set on every drive, the trips you will see, and what to check before you blame the drive.
New lesson - Lesson 9 min
Rusty on load calculations?
The method in ten steps, the traps (demand twice, wrong voltage), and the arithmetic that turns VA into amps.
New lesson - Lesson 5 min
Journeyman formula card
Three-phase, transformer, motor, power factor, fault current and 4–20 mA formulas on one printable card.
New lesson - Tool 3 min
Single and three phase formulas
The formulas you use weekly, on one printable page.
- Tool 3 min
Hoja de referencia de matemáticas del oficio
Fractions, triangles, percent and areas in one place.
- Tool 2 min
Ohm's law and power wheel
Every rearrangement of V, I, R and P, printable.
- Interactive 15 min
Fault-finding refresher
Keep the meter method sharp on a hidden control fault.
- Lesson 8 min
Meter safety refresher
CAT ratings and live-dead-live — worth re-reading every year.
- Lesson 8 min
Lockout / tagout refresher
The steps, in order, for when you are the one teaching it.
- Lesson 5 min
Symbols reference
The schematic symbols grouped by category.
- Lesson 5 min
Glosario
The trade vocabulary in plain language — handy when you are teaching an apprentice.
Ver también
- Start here — the apprentice path for your first weeks
- Tools — calculators, drills and printable sheets
- Interactive wiring diagrams
- Curso de control de motores
- Reference — glossary, symbols, formula sheets
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