Guide

AREI Electrical Symbols: Overview for Single-Line Diagram and Situation Plan

Which symbols AREI/RGIE Table 2.23 provides for Belgian domestic installations, when you introduce your own sign through the legend, and which data belongs next to every symbol on diagram and plan.

Published on 29 August 2026 Updated on 5 October 2026 9 min

AuthorStephan Behm

Short answer: Table 2.23 is the basis, the legend defines your own signs

For a domestic installation's single-line diagram and situation plan, you use the graphical symbols in AREI/RGIE Book 1, Chapter 2.13, Table 2.23. The table expressly calls itself a non-exhaustive list. If it has no suitable symbol, you use another unambiguous sign and define it in the legend of the diagram and plan (Subsection 3.1.2.1 a).

Electrical components being prepared on a workbench.

The legend is therefore a clearly regulated tool: every sign stays unambiguous throughout the records, and the mandatory technical characteristics appear on the diagram as well. This guide covers domestic installations under Book 1 V06; for non-domestic installations and special circuit diagrams, Book 1 requires further details (3.1.2.2 b).

Three layers of information

Subsection 3.1.2.1 a connects Chapter 2.13 with domestic diagrams and plans and allows the legend route when Table 2.23 has no entry. In practical terms, the documents carry three distinct layers:

the base symbol identifies the equipment family;
labels and ratings describe its electrical properties on the diagram (3.1.2.2 a);
a circuit letter and sequence number connect the electrical topology to the physical location on the plan (3.1.2.3 a).

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 situation 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.

Group	Examples	Purpose in the records
A. General marks	DC, AC, single-phase and three-phase AC	identify the nature of the supply
B. Assemblies and boxes	distribution board, general box, connection/junction box, service box, earthing switch	show structural nodes
C. Wiring systems	underground, overhead, surface, concealed, in conduit, conductor count	describe construction and installation method
D. Protective devices	fuse, circuit breaker with release letters M, O and Δ, RCD, earth electrode	show overcurrent and fault protection
E. Switches and controls	two-way, intermediate, push-button, dimmer, remote-control switch, thermostat, detector	link controls to loads
F. Socket outlets	single, multiple, splash-proof, earthed, child-protected, switched, data	distinguish connection-point functions
G. Current-using equipment	lighting, heating, appliance, motor, EV charging point, kWh meter	identify fixed or located loads
H. Sources and converters	transformer, photovoltaic cell, rectifier/inverter, DC/DC converter	record generation and conversion
J. Home automation	base mark combined with local, wireless, programmed or sensor control	combine electrical function and control method

The groups are a toolkit, not a mandatory list: you use the signs your installation actually contains. Whether equipment is correctly selected and sized is shown by the design; the symbol represents it. You state the characteristics of sources either on the single-line diagram or keep them available in the installation file (note to Table 2.23).

Twelve existing catalogue symbols side by side

The plate below shows twelve existing symbols from the PlanElec catalogue in black and white. It is a catalogue view, not a screenshot of a specific project. Read them from left to right, then row by row from top to bottom; that order matches the numbered table directly below. The raster plate enlarges the unchanged geometry from the source files. The name, position number and technical data provide the unambiguous meaning, not the shape by itself.

Black-and-white plate of twelve existing PlanElec catalogue symbols for protection devices, switches, connection points, cables and PV. — The twelve symbols follow the same order as the table: from left to right, row by row.

No. and name	Meaning in the document	Common confusion
1. Circuit breaker	Circuit breaker for overcurrent protection; rated current, curve, pole count and breaking capacity come from the technical data.	Its basic geometry is the same as the residual-current device; do not swap the name and residual-current characteristics.
2. Residual-current device	Residual-current device; type, rated residual current, rated current and pole count complete the sign.	Its basic geometry is the same as the circuit breaker; `30 mA` alone does not define a particular RCD type.
3. Main load-break switch	Load-break switch in the documented supply path.	Do not treat it as the downstream circuit breaker. Required in the main board, at least 40 A in domestic installations (5.3.5.1 b). The isolating function of the RCD at the supply point (4.2.4.3 b) is a separate requirement; the diagram shows unambiguously which device performs the main switch function.
4. Socket outlet	Ordinary socket outlet on the single-line diagram and situation plan.	Do not read it as a switched, wet-area or data outlet.
5. Wet-area socket outlet	Wet-area socket outlet with its own catalogue geometry.	The qualifier does not replace the real environmental or equipment data.
6. Socket outlet with two-pole switch	Socket outlet with a two-pole switch.	An ordinary socket and a separately documented switch carry a different meaning.
7. Lighting outlet	Lighting outlet or lighting point.	Do not confuse it with a wall luminaire or the switch controlling that point.
8. Switch	General switch symbol for a control device.	Which lighting point it controls is stated by the reference, not by the sign.
9. Connection or junction box	Connection or junction box as a topology node.	Do not treat it as a distribution board or a consumer.
10. Three-conductor cable	Base symbol for a three-conductor cable; type, cross-section and installation method are added to the cable segment.	Three conductors are not a complete cable sizing and are not the same statement as a freely chosen `3×` notation.
11. Solar panel / PV module	Solar panel or PV module as a source in the documented PV path.	Do not confuse it with the inverter; string, protection and connection point must remain separately traceable.
12. Inverter	Inverter between the sides recorded in the project.	The symbol stands for the function; manufacturer and technical limits are documented separately.

The help guide Place and connect electrical symbols explains how to place and connect a symbol on the plan before reusing it in the same project model. Catalogue symbols then appear in the diagram and plan; you confirm on site which devices are actually installed.

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 (3.1.2.2 a). Table 2.23 supplies base marks and worked examples for surface or concealed wiring, conduit, underground and overhead routes, such as a five-core 4 mm² XVB-Cca cable in embedded conduit or four insulated 1.5 mm² H07V-U conductors in one conduit.

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.

Cable sizing for current-carrying capacity, installation method, grouping, temperature, voltage drop, fault-loop conditions and protective-device selection is done separately; the symbol documents its result.

Protective-device symbols need ratings

Table 2.23 distinguishes fuses, automatic circuit breakers and residual-current devices. Capital letters next to a breaker identify its releases: M for the overcurrent release, O for the undervoltage release, Δ for residual-current sensitivity. The accompanying properties make the drawing useful:

rated current and characteristic for an overcurrent device (example in the table: 20 A, curve C);
RCD waveform type, rated residual operating current and rated current (example: 300 mA, type A, 40 A);
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 situation 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. That keeps each switch's function clear, even where several switches share a room. Multiple, switched and data outlets are different things; where the distinction matters, you use the matching sign.

When the table has no exact symbol

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

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

A manufacturer's logo does not explain electrical function or connection. A personal sign without a legend does not meet 3.1.2.1 a, 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 catches duplicate references, missing loads and accidentally copied marks early; the technical check follows.

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. That way the real function decides the symbol, not the other way round. 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:

Base mark: does the family match, such as protective device, socket, luminaire, source or fixed machine?
Characteristics: are poles, rated current, residual-current sensitivity, wiring type, conductor count and cross-section present where needed to understand the circuit?
Reference: does the point on the situation plan use exactly the circuit letter and number assigned on the single-line diagram?
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” does not replace that information. If K2 later becomes a different appliance, the reference stays; you update the symbol, functional label and 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 needs a base mark, a project legend code and a reference to its technical sheet; for home automation, Table 2.23 provides the two-part control-unit symbol of base mark and control type. A legend explains a sign missing from the table; it never hides a 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 symbol catalogue does

PlanElec provides a symbol catalogue for the Belgian planning context in the editor and uses every recorded component in the single-line diagram and situation plan. You export both documents as PDF, and the advisory AREI/RGIE self-check shows you errors in the supported rules that can be decided from project data.

The roles are clear: the catalogue keeps the representation consistent, you check the actual device, ratings, references and location before export, and the official assessment is made by the approved inspection body at the inspection.

Open PlanElec to record symbols and export both diagrams →

Basis: AREI/RGIE Book 1 V06, Chapter 2.13 (Table 2.23) and subsections 3.1.2.1 to 3.1.2.3. Editorial review: PlanElec team, 5 October 2026.

From the guide to your own electrical plan

Create a project and document circuits, cables and protective devices. Check the result against the actual installation.

Create my diagram View the example dossier (PDF)

Fictitious sample dossier, available without sign-up.

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