About Oneline

Oneline is a free single line diagram maker at singlelinediagrams.com. It is for electricians and electrical contractors who need a clean one-line for a permit or a utility application, and do not want to open a CAD program to get it.

What it does

• Starts from 40 finished drawings for EV chargers, solar, storage, generators, services, multi-unit and commercial work.
• Draws a first draft from a description of the job in plain words, and lists every value it assumed.
• Lets you edit the drawing: ratings, labels, symbols, wires, notes and the title block.
• Checks the sheet for missing ratings and title-block gaps before you export.
• Exports a vector PDF at 11 × 17 or letter size, an SVG and a PNG.

What it does not do

Oneline does not do engineering. The templates carry typical values, and a drawn draft is a draft. The load calculation, the conductor sizing and code compliance stay with you, and larger services often need an engineer’s seal. Confirm what your authority having jurisdiction expects before you submit.

Who makes it

Oneline is made by Llamacoids Inc., a shop in Burlington, Ontario that engraves lamacoid nameplates and electrical identification tags for panels, disconnects and equipment, and ships across Canada. The drawings name the equipment; the tags are what go on it.

Your drawings and your data

There is no account. Drawings are kept in your browser’s local storage and can be downloaded as files. The one exception is the describe box: what you type there, and the lettering on the sheet when you ask for a change, is sent through our server to Anthropic’s Claude to make the draft. Our server does not store it.

Contact

Email sales@llamacoids.ca or call 289-275-9572. Corrections to a template or a guide are welcome.

Image credits

Photographs of early dynamos, motors, meters and lamps on the home page: Museum of Science and Industry, Chicago and the Smithsonian National Museum of American History, via Wikimedia Commons (CC0).