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Single-line diagram maker.

Describe a power system in plain sentences and get a single-line diagram drawn to IEEE 315. Utility, generator, transformer, transfer switch, bus, breakers, loads, with ratings on every device.

Single-line DiagramEnter to send

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See it work

Four ways people ask for one.

Same tool, four requests. Every drawing below is a real render.

What you type
A 480 V critical load bus fed from utility and a 500 kW emergency generator through an 800 A automatic transfer switch, two 200 A feeders to critical loads.
Then tryAdd a 40 A breaker for a 7.4 kW EV chargerShow cable sizes on every feeder
Generator backup
Single-line diagram · IEEE Std 315 + ANSI device numbering · schematex-sld

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The drawing

What a single-line diagram is.

A single-line diagram draws a three-phase power system as one line. Every device gets its standard symbol and its rating, so an inspector can read the protection scheme at a glance.

It is the drawing a permit, a switchgear order or a commissioning pack is built on, which is why the symbols are not negotiable.

Standard
IEEE Std 315 + ANSI device numbering
Engine
schematex-sld
Editable
Double-click text, drag nodes
Export
SVG · PNG · PDF
What a single-line diagram is
Who uses it

Made for the people who have to be right.

Electrical engineersElectrical engineers

Service entries, transfer schemes and substation feeds with ratings an inspector will accept.

Solar installersSolar installers

Array, combiner, inverter and point of interconnection, in the form a utility submission asks for.

Facilities and data centresFacilities and data centres

Redundant paths, UPS and PDU topology, kept current as the hall changes.

How it works

Three steps, no drawing tool to learn.

01

Describe it

One paragraph is enough to start.

“A 480 V critical load bus fed from utility and a 500 kW emergency generator through an 800 A automatic transfer switch, two 200 A feeders to critical loads.”
02

See the drawing

Drawn by the right engine.

Generator backup
03

Say what changes

Every edit keeps a version.

Add a 40 A breaker for a 7.4 kW EV charger
V2 · DRAWN FROM V1, NOTHING RETYPED
FAQ

Common questions

What is a single-line diagram?

A drawing that shows a three-phase power system as one line, with a standard symbol and a rating for each device. Also called a one-line diagram.

Which symbol standard do you use?

IEEE Std 315 with ANSI device numbering. IEC symbols are used when you describe an IEC installation, for example a consumer unit to IEC 60364.

Can I use it for a permit or a utility submission?

It gives you a correct, readable drawing to work from. A licensed engineer still has to check and stamp it, the same as any drafted sheet.

Can I include ratings, cable sizes and device numbers?

Yes. Say them and they are placed on the drawing. Anything you leave out is simply left off.

What can I export?

SVG, PNG and PDF at any size, or a share link. The source text stays yours, so the sheet can be regenerated later.

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Draw your first single-line now.

Free account, no card. Describe the system and see it in under a minute.

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