Electrical: How Power Gets to Your Outlets

What this course is

Written for teens and adults with no electrical experience. It picks up where the electrical guides in Being an Adult 101 leave off. Each lesson explains the “why” as well as the “what”: Ohm’s law and power, why the grid runs at high voltage, how a breaker’s bimetal and magnet tell an overload from a short, how a GFCI senses a few milliamps of leakage. Facts and numbers come from U.S. government agencies (OSHA, NIOSH, CPSC, the U.S. Fire Administration, the Department of Energy and its Energy Information Administration, and BLS), university programs and OpenStax physics textbooks, and every lesson lists its sources.

How to use it

1. Start with Lesson 1 for the big picture, then go in order or jump to the part you’re curious about.
2. Each lesson has diagrams, a “parts and what they do” table, a short quiz and links to go deeper. Badges show the level.
3. Play with the interactive pieces: the power grid, the breaker, the kitchen circuit, the GFCI and the hallway switches.
4. Use the troubleshooting finder when something seems wrong, and climb the skill ladder one rung at a time.

Map of the house

The electrical system of one house, from the utility pole to the bedroom outlets. Point at a part or its name to see what it does; click to open its lesson. Switch views to see how power gets around, or what protects the people inside.

The lessons

1. 1 🗺️ The Big Picture: From Power Plant to OutletGeneration, high-voltage transmission, substations and transformers, distribution, the service, the meter, the panel and the circuits, with a map of the house. Beginner9 min✓ Done
2. 2 ⚡ Volts, Amps, Ohms and WattsOhm’s law, power, kilowatt-hours and your bill, alternating current at 60 hertz, and 120/240-volt split-phase service. Beginner9 min✓ Done
3. 3 🔌 The Service and the PanelThe service entrance, the meter, the main breaker, bus bars, how a breaker trips, fuses, neutral and ground bars, subpanels and service size. Intermediate11 min✓ Done
4. 4 🧵 Circuits and WiringBranch circuits wired in parallel, wire gauge and ampacity, cables and conduit, what the insulation colors mean, boxes, dedicated circuits, and why an overloaded circuit trips. Intermediate9 min✓ Done
5. 5 🌍 Grounding and BondingWhat the ground wire is for, the fault-current path, grounding electrodes, bonding, polarized and three-prong plugs, and double insulation. Intermediate7 min✓ Done
6. 6 🛡️ GFCIs, AFCIs and Other ProtectionHow a GFCI senses a current imbalance and how fast it trips, how an AFCI spots dangerous arcs, surge protection, tamper-resistant outlets, and smoke and CO alarms. Intermediate11 min✓ Done
7. 7 💡 Outlets, Switches and LightsReceptacle types and ratings, how single-pole, 3-way and 4-way switches work, dimmers, and LED lighting and its efficiency. Intermediate9 min✓ Done
8. 8 ⚠️ Electrical Safety and ShockWhat current does to the body, why water makes it worse, why electricians never work live, lockout/tagout, overhead power lines, extension cords and power strips, and electrical fires. Beginner7 min✓ Done
9. 9 🧪 Testing Tools and “Test Before Touch”Non-contact voltage testers and their limits, multimeters, plug-in testers, how electricians verify a circuit is dead, and what homeowners can safely test. Intermediate5 min✓ Done
10. 10 🔋 EV Charging, Solar, Batteries and GeneratorsLevel 1 and Level 2 electric-car charging, rooftop solar and inverters, home batteries, and portable and standby generators, with carbon monoxide and backfeeding dangers. Intermediate7 min✓ Done
11. 11 🔍 Troubleshooting by SymptomAn interactive finder: pick a symptom, answer one question, and get the likely causes, what you can safely check, and when to stop and call an electrician. Beginner4 min✓ Done
12. 12 🧰 Doing Your Own WorkPermits, inspections and licensing rules that vary by place, a basic tool kit, safety principles, and the skill ladder from resetting breakers to jobs for a licensed electrician. Beginner4 min✓ Done
13. 13 👷 Careers in Electrical WorkWhat electricians do, how they train through apprenticeships, licensing and the National Electrical Code, what they earn, and the job outlook. Beginner4 min✓ Done

Troubleshooting finder

Something seems wrong? Pick a symptom, answer one question, and see the likely causes, what you can safely check, and when to stop and call an electrician. Lesson 11 explains how to think it through.

The skill ladder

Build skill one rung at a time. The first two rungs need no tools beyond a lamp and a flashlight. Higher rungs depend on your local rules, and the top one belongs with licensed electricians. Lesson 12 covers permits, tools and safety principles.

1. 1

   First jobs

   No tools beyond a lamp and a flashlight. Nothing to open or unscrew.

   • Reset a tripped breaker
   • Label your panel’s breakers
   • Test and reset GFCIs every month
   • Test smoke and CO alarms every month
   • Press TEST on AFCI breakers monthly
   • Replace bulbs with LEDs under the fixture’s wattage limit
   • Replace a blown fuse with one of the same rating
   • Spot warning signs: warm plates, loose plugs, flickering
2. 2

   Next steps

   Planning and math. Still nothing opened up.

   • Add up watts and amps on each circuit and spread out the load
   • Read your meter and electric bill
   • Use extension cords and power strips safely, temporarily
   • Use a portable GFCI for outdoor tools
   • Add plug-in or battery CO alarms where they’re needed
   • Make a power-outage and generator safety plan
3. 3

   Where local rules allow homeowners

   Only if your city or state permits it, often with a permit and inspection, with power off and proven dead. Otherwise, hire an electrician.

   • Replace a receptacle or switch like-for-like
   • Replace a light fixture like-for-like
   • Install a dimmer rated for your LED bulbs
4. 4

   Leave these to licensed electricians

   They need a license, permits and inspections, and training a homeowner doesn’t have.

   • Anything inside the panel, including breakers
   • Service upgrades, meters and service wires (with the utility)
   • New circuits and new outlets
   • Aluminum-wiring repairs (CPSC: don’t try it yourself)
   • Adding GFCI and AFCI breakers
   • Hardwired smoke alarms
   • EV chargers, solar, batteries and standby generators
   • Generator transfer switches (OSHA: a qualified electrician)

Careers

Electricians install, maintain and repair electrical power, communications, lighting and control systems. Here are the U.S. Bureau of Labor Statistics figures from its Occupational Outlook Handbook (page last modified August 27, 2026):

Most electricians learn the trade in a 4- or 5-year paid apprenticeship, and most states require electricians to pass a test on the National Electrical Code and state and local codes and be licensed. Lesson 13 has the details, the training path and how registered apprenticeships work.

Sources

Each lesson lists the sources for its own facts. Here they all are in one place.