Anyone facing an electrical file for the first time trips over two words: single-line diagram and position diagram. The single-line diagram is the technical overview of your installation. It starts at the meter and the distribution board, then shows every circuit with its protective device, cable size and connected appliances.
Why "single-line"?
On the diagram a circuit is drawn as one single line, even though it really consists of several conductors (line, neutral and earth). That keeps the drawing readable: you see the structure of the installation at a glance without drowning in cable detail. Small ticks or a number on the line indicate how many conductors actually run there.
What goes on it?
- The origin of the installation: service connection, meter and main switch.
- The residual-current devices, with their sensitivity (300 mA, 30 mA).
- Every circuit with its breaker or fuse, cable type and cross-section.
- The connected points: lighting, sockets, fixed appliances.
- Earthing: earth loop, earthing conductor and equipotential bonding.
Single-line or position diagram?
Both are mandatory and they complement each other. The single-line diagram answers "how is it built electrically?". The position diagram answers "where is it?": a simplified floor plan showing each point with its symbol and circuit number. An inspector uses the two together to understand your installation.
Related reading
How Voltuno helps
Drawing a single-line diagram should not take days. With Voltuno you draw a correct single-line diagram, position diagram and matching bill of materials in minutes, straight from your browser. The software is built around AREI requirements, so you work faster and walk into the inspection with a clear, complete file.
Please note: this article is a general explanation and not legal advice. Always consult the official, consolidated AREI text (FPS Economy) for the exact obligations and article references.
