Which section of electric cable for which purpose?
There is so much to know about electricity! In the meanders of the standard NF C 15-100, it is sometimes difficult to navigate for budding DIYers; and sometimes, rest assured, even for an electrician!
To know what is the right color of electric wires, how to wire a GTL (technical housing sleeve), to wire a plug, a switch-breaker, etc … These subjects have been the subject of previous articles, which you can now refer to perfect your knowledge about your electrical network.
The different sections of electric cable
In this new article, I will address a broad topic, namely the different sections of electrical cables and which of them to choose according to your needs?
Indeed, it should be known that an electrical circuit acts as a piping network. The more important the need to pass energy will be (power required), the more the diameter of your cables will be important.
To summarize, the diameter of an electric cable depends on the need for intensity and power.
For a domestic installation, the adapted voltage is 230 V. Here are the sections of electric cables necessary according to the need in intensity and power of your installation:
Application Power Intensity Diameter needed
Lighting circuit, controlled outlet 2,300 W 10 A or 16 A max. 1.5 mm²
8 electrical outlets maximum 2 300 W 16 A max 1.5 mm²
12 sockets maximum 3 680 W 20 A max 2.5 mm²
Radiator <3 680 W 3 680 W 16 A max 1.5 mm²
Radiator <4,600 W 4 600 W 25 A max 2.5 mm²
Radiator <5 750 W 5 750 W 25 A max 4 mm²
Radiator <7 360 W 7 360 W 32 A max 6 mm²
Underfloor heating <1,700 W 1,700 W 20 A max. 1,5 mm²
Underfloor heating <3 400 W 3 400 W 20 A max 2.5 mm²
Underfloor heating <4,200 W 4,200 W 25 A max. 4 mm²
Underfloor heating <5 400 W 5 400 W 32 A max 6 mm²
Underfloor heating <7,500 W 7,500 W 40 A max 10 mm²
General circuit breaker 9 200 W 40 A max 10 mm²
Special cases: VMC or VMR
The standard NF C 15-100 recommends connecting a controlled mechanical ventilation, or distributed mechanical ventilation to a circuit breaker of 2 Amperes, using conductors of section 1.5 mm².
The case of electric shutters
The electric shutter mechanism must be connected to a 16 A protective device, using 1.5 mm² electrical cables.
And for charging stations for rechargeable hybrid vehicles or electric vehicles:
32 A: The charging station will be connected to a 40 Amp circuit breaker, with electrical wires of 10 mm² section.
16 A: The charging station will be connected to a 20 amp circuit breaker, with 2.5 mm² conductors.
Single-phase electric water heater
The water heater will be connected to a 20 A protection device, using 2.5 mm² electrical cables.
Hob, electric stove
In single-phase circuits, the cooking elements will be connected to a 32 A circuit-breaker connected to conductive cables of at least 6 mm².
Other electrical circuits
For other circuits, here are the common uses:
1.5 mm²: 16 A
2.5 mm²: 20 A
4 mm²: 25 A
6 mm²: 32 A
Conclusion
The installation of a circuit is very sensitive, the slightest error could have serious consequences. Do not hesitate, in case of doubt, to call a professional.
