Electrical unit and associated additional functional module

An electrical apparatus for an electrical installation, able to be connected to an electrical grid, comprising at least:

• a primary functional module comprising a first connection pole able to be connected to a first line of the electrical grid, a second connection pole able to be connected to a second line of an electrical circuit of the electrical installation and a third connection pole able to be connected to a third neutral line of the electrical grid,
• the primary functional module being able to perform a function of interrupting the current between the first connection pole and the second connection pole and comprises a control member such that, in an open position, an electrical circuit between the first connection pole and the second connection pole is open and that, in a closed position, the electrical circuit is closed,
• an additional functional module comprising means for performing at least one function requiring an electric power supply, comprising at least a fourth connection pole and a fifth connection pole that are electrically connected respectively to the first connection pole and to the third connection pole of the primary functional module in order to supply power to the additional functional module,
• a reception module comprising at least a first reception area for receiving the primary functional module,
• wherein the reception module comprises a second reception area for receiving the additional functional module,
• and in that said at least one function of the additional functional module is a function requiring an electric power supply, excluding a lighting function.