Electrical diagram maker
A free electrical diagram maker for single-line (one-line) diagrams and wiring diagrams, with a library of electrical symbols, ready templates and PNG, PDF and SVG export. US (NEC) practice only.
What an electrical diagram maker is
An electrical diagram maker is a drawing tool for laying out electrical systems with standard symbols joined by connectors, so that sources, protective devices, panelboards and loads can be shown and labeled without drafting software. The Ampxa workspace is a free diagram maker that runs in the browser: diagrams are drawn on a canvas, saved on the device and exported as images or PDF.
It suits the drawings electricians and designers make for planning and communication: a single-line diagram of a service, a wiring diagram of a room, a sketch for a customer or a crew, or a record of what was installed.
What's included
- Symbol library: Circuit breaker, Fuse, Transformer, Motor, Generator, Solar module, EV charger, Ground, Single-pole switch, Battery, Meter, Receptacle (single), Lighting outlet, Resistor, Capacitor, Duplex receptacle, GFCI receptacle, Panelboard, Disconnect, Junction box, Light fixture, Three-way switch, Recessed light, Smoke alarm, each with the meaning listed in the legend below.
- Templates: a single-line diagram and a residential wiring diagram that open as new boards, with ratings as editable placeholders, alongside flowcharts, checklists and job boards.
- Connectors: straight, curved and elbow connectors that attach to the sides of a symbol and stay attached when it moves, with optional arrowheads.
- Labels: text on every symbol and connector, for ratings, conductor sizes and circuit numbers.
- Legend: a legend item that names every electrical symbol on the board and adds or drops rows as symbols come and go.
- Export: PNG at several resolutions, PDF and SVG, plus a JSON backup that reopens for editing.
- Mobile: the editor works on phones, with pinch to zoom and one bottom toolbar; diagrams are stored in the browser on that device.
Types of electrical diagrams
A single-line diagram, also called a one-line diagram, shows a power system with one line standing for all the conductors of a circuit. It runs from the source, through the service, the main disconnect and the panelboards, to the major loads, with ratings beside each item. Single-line diagrams are used for service and feeder design, utility applications, generator and solar interconnections, and as the map of a building's distribution.
A wiring diagram shows how individual devices are connected: which receptacles, switches and lights are on each branch circuit and how the conductors run between them. It is used for room layouts, remodels and troubleshooting a circuit.
A schematic shows how a circuit works rather than where things are, with components drawn in logical order. Motor control circuits, relay logic and electronic circuits are drawn as schematics.
A riser diagram shows equipment by floor in a multi-story building: the service at the bottom and the feeders rising to the panelboards on each level. It is used in commercial and multifamily drawings to show vertical distribution.
How to make a single-line diagram
- Open the single-line diagram template, or start a blank diagram.
- Start at the source: the utility service or transformer, with its voltage and available capacity.
- Add the meter and the main disconnect, with the main breaker rating.
- Where there is a standby source, add the generator and the transfer switch between the service and the panelboard it feeds.
- Add the main panelboard and draw each feeder to a subpanel or transformer, labeling the conductor size and overcurrent rating.
- Add the major loads, such as motors, HVAC equipment and EV chargers, with their ratings.
- Add the grounding electrode system and check every placeholder has been replaced with a real value.
- Export the diagram as PDF or PNG.
Ratings and conductor sizes come from calculations and equipment data, not from the drawing. The breaker size calculator, transformer sizing calculator and generator sizing calculator cover the common checks, and the panel schedule template records the circuits in each panelboard.
Single-line diagram vs wiring diagram
| Single-line diagram | Wiring diagram | |
|---|---|---|
| Shows | The distribution system as a whole | Devices on individual circuits |
| Conductors | One line per circuit, whatever the number of wires | Individual runs, travelers and switched legs |
| Typical items | Service, meters, disconnects, transformers, panelboards, feeders, generators | Receptacles, switches, lights, junction boxes |
| Ratings shown | Voltage, ampere and kVA ratings, conductor sizes | Circuit numbers, device types, cable types |
| Used for | Service and feeder design, interconnection, records | Room layouts, remodels, troubleshooting |
Electrical symbol legend
The symbols below are the electrical set the workspace provides, as they appear on a board.
| Symbol | Name | Meaning |
|---|---|---|
| Circuit breaker | An overcurrent device that opens a circuit on overload or short circuit and can be reset. | |
| Fuse | An overcurrent device whose element melts to open the circuit; it is replaced after operating. | |
| Transformer | Changes voltage between two windings, such as a utility transformer or a 480 V to 208Y/120 V dry-type unit. | |
| Motor | A motor load, usually labeled with horsepower, voltage and phase. | |
| Generator | A generator, often a standby source connected through a transfer switch. | |
| Solar module | A photovoltaic module or array. | |
| EV charger | Electric vehicle supply equipment (EVSE). | |
| Ground | A connection to the grounding electrode system or to ground. | |
| Single-pole switch | A single-pole switch that controls a load from one location. | |
| Battery | A battery or energy storage system. | |
| Meter | A utility revenue meter or other metering point. | |
| Receptacle (single) | A single receptacle outlet. | |
| Lighting outlet | A lighting outlet: the box for a ceiling or wall luminaire. | |
| Resistor | A resistor, used in control and electronic schematics. | |
| Capacitor | A capacitor, as in power factor correction or electronic schematics. | |
| Duplex receptacle | A duplex receptacle: two receptacles on one yoke. | |
| GFCI receptacle | A receptacle with ground-fault circuit-interrupter (GFCI) protection. | |
| Panelboard | A panelboard: the bus and the overcurrent devices for feeders and branch circuits. | |
| Disconnect | A disconnecting means that isolates equipment from its supply. | |
| Junction box | A junction box where conductors are spliced. | |
| Light fixture | A luminaire (light fixture). | |
| Three-way switch | A three-way switch; a pair controls one light from two locations. | |
| Recessed light | A recessed luminaire (can light) set into the ceiling. | |
| Smoke alarm | A smoke alarm location, shown as a placeholder for the alarm layout the local code requires. |
Limitations
Diagrams made in the workspace are drawings for planning and communication. The workspace does not check ratings, conductor sizes, clearances or code compliance, and the symbols are a practical set rather than a complete drafting standard. Permit and construction drawings follow the requirements of the local authority having jurisdiction, which may call for particular symbols, title blocks, scales or an engineer's seal.
Diagrams are stored in the browser on the device where they were made and do not sync between devices; a JSON export keeps an editable backup. The templates follow US (NEC) practice only.
Frequently asked questions
Is a one-line diagram the same as a single-line diagram?
Yes. Both names describe a diagram that represents each circuit of a power system with one line, whatever the number of conductors, and shows the sources, protective devices, transformers, panelboards and loads with their ratings.
Which electrical symbols does the diagram maker include?
The workspace provides 24 electrical symbols, including the circuit breaker, fuse, disconnect, transformer, generator, meter, panelboard, receptacles, GFCI receptacle, switches and lighting outlets. The legend on this page lists each one with its meaning.
Can a diagram from the workspace be used for a permit?
It can be included where the local authority accepts that kind of drawing, but requirements vary. Many jurisdictions accept a simple single-line diagram for residential service work, while commercial projects often need drawings prepared or sealed by a registered engineer.
Where are the diagrams saved?
In the browser's own storage on the device where they were made. They are not uploaded. Exporting a JSON backup keeps a copy that can be imported on another device or after browser data is cleared.
Does the diagram maker work on a phone?
Yes. On a phone the editor shows a slim top bar and one bottom toolbar, pinch zooms the canvas, and menus open as bottom sheets. A larger screen is easier for big single-line diagrams.