Wiring and installation: conductors, section, environment and execution
How AREI considers cable choice, installation method, external influences, voltage drop and conductor protection.
Uitleg
This page summarizes AREI Book 1 rules about electrical conductors and installation. The main references are subsections 3.1.2.2, 5.2.1, 5.2.4, chapter 4.4 and the rules about external influences and installation methods in Part 5.
Looking for the meaning of cable section, wire types or voltage drop first? See Wiring and Electricity basics.
In short
- A cable is not only a line on the diagram: type, section, conductor count and installation method matter.
- The conductor must withstand load, environment, mechanical influences and short circuit.
- Overcurrent protection must match the conductor's admissible current.
- Voltage drop must remain compatible with correct operation of the installation.
- The one-line diagram must show the relevant conductor properties.
What should you know about a conductor?
For a household one-line diagram, AREI requires at least the characteristics of the electrical conductors: type, section and conductor count. The installation method also belongs in the dossier.
These values are not decorative. They help determine whether the breaker rating, RCD structure, voltage drop or installation method can be defended.
| Information | Why it matters |
|---|---|
| Conductor type | Determines mechanical, thermal and fire properties |
| Section | Determines admissible current and voltage drop |
| Conductor count | Determines phase, neutral, earth, control and supply type |
| Installation method | Affects cooling, protection and admissible current |
| Length | Matters for voltage drop and short-circuit calculation |
Cable section without context is not enough
Two cables with the same section can be assessed differently because of installation method, environment, grouping or length. Record more than “2.5 mm²”: include the conductor type and relevant installation conditions.
Overcurrent and conductor choice
AREI sets the overcurrent rules in chapter 4.4. The admissible current of a conductor depends on section, insulation, installation method and environment. The protective device must protect the conductor against overload and short circuit.
Design choice
Choose conductor and protection together.
- load;
- cable type;
- section;
- installation method;
- length and voltage drop.
Diagram information
Document enough to make that choice checkable.
- breaker rating;
- cable section;
- cable type;
- conductor count;
- endpoints and appliance load.
External influences
The environment determines which equipment and installation method are suitable. Consider moisture, temperature, mechanical loads, fire risk, corrosion and public access.
A conductor in a dry internal wall does not receive the same assessment as a cable to an outbuilding, outdoor installation, bathroom zone, charging point or technical room.
| Context | What needs extra attention |
|---|---|
| Outdoors or garden | Moisture, mechanical protection, route and voltage drop |
| Bathroom | Zones, IP rating, RCD protection and equipotential bonding |
| Outbuilding | Length, supply, sub-board and earthing/protection logic |
| EV charger | Dedicated circuit, continuous load, RCD and overcurrent protection |
| PV/battery | Source side, DC/AC separation, protection and technical documents |
In Condui
Use the cable fields consistently. Once type, section and protection are filled in, the diagram can become checkable instead of only drawable.
Common errors
- Drawing the circuit without recording cable type or section.
- Treating a long cable to a garden or outbuilding as short indoor wiring.
- Forgetting the smallest section in a route.
- Reusing existing conductors without showing what is actually installed.
- Documenting PV, battery or EV separately without connecting it to the household installation.