What is a three-phase connection?
Single-phase, three-phase... you want to connect an electrical appliance but don't know which type of connection to choose? One-Elec reviews the basics with you.
To put it simply, in terms of electrical connections, you have two choices: single-phase and three-phase. What is the difference?
- Single-phase uses a phase wire and a neutral wire
- Three-phase comes in two types:
- - three-phase (400-volt motors and machines)
- - three-phase + neutral (four-pole for 400-volt machines with electronic circuits).
What is the difference between a three-phase and a single-phase electrical installation?
Choose a three-phase connection for large electrical equipment and a single-phase connection for small equipment. Why? Because the more phases there are, the better the energy distribution!
In the case of a three-phase connection, each phase supplies an alternating voltage (often 230V between phase and neutral, and 400V between two phases).
The distribution of the electrical load is therefore better → more balanced → more stable power supply.
We therefore prefer three-phase for all large electrical equipment (industrial machines, pumps, etc.). .
When should you choose a three-phase connection?
Three-phase is necessary when the power of your electrical installation exceeds 12 kVA. This type of connection is often used in industrial networks to power motors and machines, in businesses and workshops that use powerful equipment, in buildings equipped with high-performance heat pumps, and in certain modern heating installations. Single-phase power is perfectly suited to standard residential installations without particularly energy-intensive equipment.
Disadvantages of three-phase electrical installations
If you don't need it, don't install a three-phase connection: it will cost you more and require more technical installation that is not necessary.
Step-by-step guide to installing a three-phase connection
Before installing any three-phase connection, it is essential to check whether your network can support a three-phase power supply. An electrician or your energy supplier will be able to advise you. Only if your installation is compatible can you request a three-phase connection from your supplier. This often involves changing your meter and updating your contract.
Next, you will need to install a suitable electrical panel equipped with three-phase circuit breakers, a residual current device and a distributor to balance the loads across the three phases.
To carry out the wiring, you must:
- Connect each phase to separate circuits to avoid overload
- Install suitable sockets if necessary
- Check the output voltage for each connected device.
Once your installation is complete, carry out tests to check that the circuits are working properly and that the phases are balanced.
Please note that it is essential to wear personal protective equipment. Using insulated tools helps to prevent accidents. If in doubt, calling in a professional electrician is always the best option.
Knowing how my electrical installation is connected
To find out about your current installation, you can check:
- Your electricity meter: if it is three-phase, it will display three phases (L1, L2, L3) and a neutral
- Your electrical panel: a three-phase system has circuit breakers distributed over three phases
- Your electricity contract: it will state the type of connection
Do you have a question or other electrical request? Feel free to consult our technician.
