AREI Electrical Symbols: A Guide for Both Domestic Diagrams

Short answer: Table 2.23 is authoritative but deliberately non-exhaustive

For a domestic installation's single-line diagram and position plan, AREI/RGIE Book 1 points to the graphical symbols in Chapter 2.13, Table 2.23. The table expressly calls itself a non-exhaustive list. If it has no symbol for an item, another unambiguous symbol may be used when that symbol is defined in the legend of the diagrams.

This is not permission to use unexplained icons. A symbol must remain identifiable throughout the records, and it does not replace mandatory technical characteristics. This guide concerns domestic installations under Book 1 V06. Non-domestic systems and some multi-line circuit diagrams can require further standardised symbols and details.

Three layers of information

Subsection 3.1.2.1 connects Chapter 2.13 with domestic drawings. In practical terms, the documents carry three distinct layers:

1. the base symbol identifies the equipment family;
2. labels and ratings describe its electrical properties;
3. a circuit letter and sequence number connect the electrical topology to the physical location.

An RCD symbol without its type and ratings is incomplete. A line from a breaker to a socket says nothing yet about cable type, cross-section, conductor count or installation method. A point on the position plan that does not share the single-line reference cannot be reliably reconciled with the circuit.

The principal Table 2.23 groups

The overview below describes meaning, not the exact geometry of each official mark.

The table is not a bill of materials. A project does not need every sign, and using an official sign does not prove correct product selection, connection or sizing.

A wiring symbol is more than a line

The single-line diagram records at least wiring-system type, cross-section, number of conductors and installation method. Table 2.23 supplies base marks and worked examples for surface or concealed wiring, conduit, underground and overhead routes.

Notation should reflect the installed system. 3G2.5, for example, communicates three conductors including a green-yellow protective conductor, each 2.5 mm². A notation using × does not necessarily make the same PE statement. Concealed wiring must not be drawn as surface wiring, or vice versa, merely to simplify the page.

Nor is the symbol a cable calculation. Current-carrying capacity, installation method, grouping, temperature, voltage drop, fault-loop conditions and protective-device selection still need a full assessment.

Protective-device symbols need ratings

Table 2.23 distinguishes fuses, automatic circuit breakers and residual-current devices. Their accompanying properties make the drawing useful:

• rated current and characteristic for an overcurrent device;
• RCD waveform type, rated residual operating current and rated current;
• identified functions where a device has multiple releases;
• the earthing connection that actually exists.

“30 mA” does not say whether an RCD is Type A, F or B, or whether it is instantaneous or selective. “20 A” without a characteristic and corresponding conductor data is not a complete circuit description. Copy values from the installed equipment and verified design, not from a sample drawing.

One reference across both diagrams

Each elementary circuit receives a capital letter on the single-line diagram. Lighting points, socket outlets and control units are numbered in order starting at the upstream overcurrent device. The position plan uses the same letter and number.

Therefore B3 must identify the same item on both documents. A switch or control unit is referenced using its circuit and the number of the lighting point or appliance it controls. This preserves function where several switches share a room. Multiple, switched and data outlets should not be collapsed into one generic socket mark when the distinction describes the installed system.

When the table has no exact symbol

The legend rule supports new functions and specialist equipment. A defensible process is:

1. first test whether a general Table 2.23 mark plus a technical label is clear;
2. otherwise choose a simple mark that cannot be confused with an existing one;
3. define the mark, abbreviation and precise meaning in the legend;
4. use it consistently on every relevant page;
5. keep the electrical properties on the diagram or in the installation dossier.

A manufacturer's logo alone rarely explains electrical function or connection. A personal sign without a legend remains ambiguous even if its author remembers the meaning.

Common documentation errors

• importing a DIN, IEC or software mark without checking its meaning in this drawing;
• using one socket mark for ordinary, multiple, switched and data outlets;
• omitting cable type, cross-section, conductor count or installation method;
• labelling an RCD only “30 mA”, without type and rated current;
• using different references on the single-line and position diagrams;
• reducing a PV installation to a panel icon without source, inverter and relevant characteristics;
• stylising the drawing until the official base mark or defined legend is no longer recognisable.

Inspect the final PDF, not only the editor

A correct symbol can become unusable through scaling or pagination. Review the export at ordinary reading size: does a page edge cut off a legend or rating, do lines cross identifiers, can ordinary and switched sockets still be distinguished, and is every label clearly attached to the intended device?

Do not make meaning depend on colour alone. Inspection records may be printed or copied in black and white. Shape, text and circuit reference must carry the information. Put the legend on affected pages or reference it unambiguously as part of the same document set, and keep abbreviations consistent.

Finally compare identifiers and counts across the two diagrams. This is not an electrical inspection, but it can expose duplicate references, missing loads and accidentally copied marks before the dossier is handed over.

A repeatable workflow from survey to legend

Do not begin with drawing. First make an equipment register in which every real point has a room, circuit, sequence number, function and the characteristics that will have to accompany its mark. Only then choose the closest base symbol from Table 2.23. This prevents a convenient-looking icon from deciding what the equipment supposedly is. A fixed fan, a socket outlet and a connection box may share one circuit, but they remain different items.

Review every entry in four passes:

1. Base mark: does the family match, such as protective device, socket, luminaire, source or fixed machine?
2. Characteristics: are poles, rated current, residual-current sensitivity, wiring type, conductor count and cross-section present where needed to understand the circuit?
3. Reference: does the point on the position plan use exactly the circuit letter and number assigned on the single-line diagram?
4. Legend: is every project-specific combination defined once and easy to find on every affected sheet?

Consider circuit K: it starts downstream of an identified RCD and a 20 A protective device, continues through a recorded 3G2.5 cable and supplies three fixed connections. The protective device carries its ratings, the cable carries its wiring data, and the connections are referenced K1 to K3. One generic icon labelled “kitchen” would not preserve that structure. If K2 later changes function, keep the stable reference and update the symbol, functional label and relevant characteristics on both diagrams.

Handling boundary cases without hiding information

For combined equipment, decide which electrical functions must remain visible for inspection and maintenance. A multi-socket assembly may be grouped if its quantity and switching remain unambiguous. A smart actuator with several outputs may instead need an official base mark, a project legend code and a reference to its technical sheet. A legend is not permission to omit the conductor path, protective function or energy source.

Version project-specific marks like any other installation data. When a definition changes, record the date and affected references, then inspect every sheet. Do not leave an obsolete legend beside the current PDFs in the handover folder. If the representation is uncertain, settle it with the responsible electrical professional and, where appropriate, the approved inspection body before work is executed.

The official AREI/RGIE Book 1 publication remains the primary source. Check the edition applicable to the document date there. Manufacturer icon libraries and symbols borrowed from another country's standard do not replace Table 2.23 or the Belgian diagram rules.

What PlanElec's catalogue does and does not prove

PlanElec provides an electrical-symbol catalogue for Belgian documentation. Recorded components can feed the single-line diagram and position plan and be exported as PDF. The indicative self-check covers only supported rules for which the project contains sufficient data.

The catalogue does not prove that every specialist item or every AREI case is fully modelled or checked. Verify the actual device, ratings, references and physical location before export. A well-rendered symbol is not a complete design, an AREI conformity statement or an approved inspection report.

Related guidance

• Single-line diagram vs. position plan: difference and coordination
• Create a single-line diagram step by step
• Cable cross-section and protective device

Open PlanElec to record symbols and export both diagrams →

Basis: AREI/RGIE Book 1 V06, Chapter 2.13 and subsections 3.1.2.1 to 3.1.2.3. Official Table 2.23 and the installed system remain decisive.