Have you heard of single and three-phase, 230V or 400V, amperage or kVA? Do you want to know which connection is right for you? And what are the consequences for your installation and your bill? We explain it all to you.

A standard connection in Brussels is single-phase, 230V, 40 amps. It delivers a power of 9.2 kVA. But what do these terms mean? And does this standard connection meet your needs? Read our information to find the answers to your questions.

About your connection and its power

Whatever type of connection you have, it is defined by 3 elements:  

  • The circuit voltage, which is expressed in Volts (V)
    In Belgium, there are 2 voltage systems: either 230V or 400V.  In Brussels, 80% of the territory is covered with 230V. 
  • The electrical current, expressed in amperes (A).
    This indicates the maximum current that your installation can withstand. 
    The standard installation is 40 amps single-phase 230V. It delivers a power of 9.2 kVA. If we translate this into watts, it represents more than 9,000 watts. 
  • The number of phases, to determine whether the connection is single-phase or three-phase.

Single-phase or three-phase?

The single-phase connection differs from the three-phase by the number of wires that arrive in the electrical panel. Three-phase is the most powerful.

  • Do you see two wires? You have a single-phase connection.
  • Three wires arrive at the meter? You have a three-phase connection.
  • Finally, if you see four wires, this means that you are in three-phase + neutral (a blue wire for neutral).
    This is also called tetraphase or 3N-phase.  Three-phase with neutral is only possible with 400V

When do you need three-phase?  

Three-phase is necessary if you use power-hungry appliances or equipment. This is the case for any machine with a motor.
Examples? A lift, a sauna, powerful ovens for the bakery, catering or ceramics industry. To use this equipment, you need more power.

Can I go from 230V to 400V?

You can go from 230V to 400V by introducing a work requestPlease note: 400V is not available everywhere. Additional free study will determine if this is possible.

If it is impossible to have 400V, you always have the option of installing an autotransformer. It is also possible to switch from a single-phase connection to a three-phase connection or vice versa.

Which meter power (in kVA) for which current (Ampere)?

The higher the voltage and current, the higher the power of your meter. Consult the table below to find out how much power you need in relation to the current you need.


230 V - single-phase

230 V - three-phase 400 V - three-phase+N
16A 3,7 kVA 6,4 kVA 11,1 kVA
20A 4,6 kVA 8 kVA 13,9 kVA
25A 5,8 kVA 10 kVA 17,3 kVA
32A 7,4 kVA 12,7 kVA 22,2 kVA
40A 9,2 kVA 15,9 kVA 27,7 kVA
50A 11,5 kVA 19,9 kVA 34,6 kVA
63A 14,5 kVA 25,1 kVA 43,6 kVA