Source: https://mokxi.com/learn/path/reading-electrical-drawings Updated: 2026-11-11 All paths # Reading electrical drawings Symbols, schematics, wiring diagrams, ladder diagrams, one-lines, floor plans and panel schedules, each read on the page and then proved on a circuit that runs. Free 8 lessons 5 h 6 chapters 1,625 XP Electrical ยท Beginner +100 XP 0 of 8 done Start the course free Symbols: the alphabet of a drawing Lesson plan for teachers What you will build ## 2 projects, built step by step 8 lessons in 6 chapters, about 5 hours on a simulated breadboard. Free, in your browser, every step checked by the simulator. Chapter 1 project ### Nodes, dots and what a meter sees Three resistors and a meter: what a node is, why a dot means joined, and how to read the voltage a drawing predicts before you measure it. Open it in the simulator Chapter 4 project ### Floor plans: a hallway with three switches Read the switch symbols on an electrical floor plan, S, S3 and S4, and prove a three-switch hallway on a logic model: any switch flips the light. Open it in the simulator The map ## Chapter by chapter Each lesson opens when the one before it is done, and each chapter ends in a project. Chapter 1 ## Symbols and schematics The alphabet of a drawing, and what a node really is. Open 150 XP ### Symbols: the alphabet of a drawing Read a first schematic symbol by symbol, a supply, a switch, a resistor, an LED and ground, then prove each one on the circuit it describes. 0 of 5 steps Start What is in it Project Locked 300 XP ### Nodes, dots and what a meter sees Three resistors and a meter: what a node is, why a dot means joined, and how to read the voltage a drawing predicts before you measure it. 0 of 5 steps Chapter 2 ## Wiring diagrams Where every wire lands, on a three-way switch. Locked 150 XP ### Wiring diagrams: where every wire lands A three-way switch drawn two ways: as a schematic that shows how it works and as a wiring diagram that shows which terminal every traveler lands on. 0 of 5 steps Chapter 3 ## Ladder diagrams Rails, rungs, contacts, coils and the seal-in. Locked 175 XP ### Ladder diagrams: rails and rungs The drawing every industrial electrician reads: two rails, rungs of contacts and coils, normally open and normally closed, and the seal-in that keeps a motor running. 0 of 6 steps Chapter 4 ## One-lines and floor plans A whole power system on one line, and switches on a plan. Locked 175 XP ### One-line diagrams: a whole system on one line A generator transfer switch read from its one-line: two sources, two interlocked contactors and a load, then an outage and a transfer on a low-voltage model. 0 of 6 steps Project Locked 300 XP ### Floor plans: a hallway with three switches Read the switch symbols on an electrical floor plan, S, S3 and S4, and prove a three-switch hallway on a logic model: any switch flips the light. 0 of 5 steps Chapter 5 ## Panel schedules What every breaker feeds, and how loaded each leg is. Locked 175 XP ### Panel schedules: what every breaker feeds Read a panel schedule, circuit numbers, breaker sizes, loads and legs, then watch a monitor flag a circuit over 80 percent, an overload and an unbalanced panel. 0 of 6 steps Chapter 6 ## Boss project Build a motor starter from its ladder drawing. Locked 200 XP ### Boss: build it from the drawing The motor starter with three control wires missing. Read the ladder, draw each wire where the drawing says, prove the seal-in and the stop, then build revision B. 0 of 7 steps Syllabus ## Every lesson in the course All 8 lessons, in order, each with what it covers. Any of them opens in the editor right away. Chapter 1 ### Symbols and schematics - Symbols: the alphabet of a drawing Read a first schematic symbol by symbol, a supply, a switch, a resistor, an LED and ground, then prove each one on the circuit it describes. - Nodes, dots and what a meter sees Three resistors and a meter: what a node is, why a dot means joined, and how to read the voltage a drawing predicts before you measure it. Chapter 2 ### Wiring diagrams - Wiring diagrams: where every wire lands A three-way switch drawn two ways: as a schematic that shows how it works and as a wiring diagram that shows which terminal every traveler lands on. Chapter 3 ### Ladder diagrams - Ladder diagrams: rails and rungs The drawing every industrial electrician reads: two rails, rungs of contacts and coils, normally open and normally closed, and the seal-in that keeps a motor running. Chapter 4 ### One-lines and floor plans - One-line diagrams: a whole system on one line A generator transfer switch read from its one-line: two sources, two interlocked contactors and a load, then an outage and a transfer on a low-voltage model. - Floor plans: a hallway with three switches Read the switch symbols on an electrical floor plan, S, S3 and S4, and prove a three-switch hallway on a logic model: any switch flips the light. Chapter 5 ### Panel schedules - Panel schedules: what every breaker feeds Read a panel schedule, circuit numbers, breaker sizes, loads and legs, then watch a monitor flag a circuit over 80 percent, an overload and an unbalanced panel. Chapter 6 ### Boss project - Boss: build it from the drawing The motor starter with three control wires missing. Read the ladder, draw each wire where the drawing says, prove the seal-in and the stop, then build revision B. Kits ## Build it on your bench too Every lesson runs in the simulator with nothing to buy. When you want the real thing, these kits have the parts. Have a kit already? ### Find your kit Pick the starter kit you own and run every lesson in its manual with the same parts on the same pins. See every kit Questions ## About Reading electrical drawings Is Reading electrical drawings free? Yes. All 8 lessons of Reading electrical drawings are free and run in your browser, with nothing to install and no parts to buy before you start. Do I need any parts? No. Every circuit is built on a simulated breadboard, and the simulator checks each step as you go. When you want to build it for real, the same parts and wiring work on a real bench. How long does Reading electrical drawings take? About 5 hours: 8 lessons in 6 chapters, each one a few short steps. Your progress is kept, so you can stop after any lesson and pick up where you left off. What will I build? Each chapter ends in a project that puts it together: Nodes, dots and what a meter sees and Floor plans: a hallway with three switches. Where do I start? With "Symbols: the alphabet of a drawing", and each lesson builds on the one before it. New to circuits? Electronics basics is the course that starts from zero.