Functional module for an electrical connection enclosure comprising: - one or more monitoring-and-control units, - a protection unit, common to all of the monitoring-and-control units, configured to supply electrical power to all of the monitoring-and-control units and to electrically protect all of the monitoring-and-control units, characterized in that the functional module also comprises: - a segment of computer bus, configured to connect all of the monitoring-and-control units to an industrial computer, - just as many external connection modules as there are monitoring-and-control units, each external connection module being configured to connect an electrical load which is outside the electrical connection enclosure to a monitoring-and-control unit and to supply electrical power to this electrical load from this monitoring-and-control unit, - just as many input-output modules as there are monitoring-and-control units, each input-output module being configured to connect the computer bus segment to a monitoring-and-control unit and to the electrical load connected to this monitoring-and-control unit and to allow the exchange of operating data between said electrical load on the one hand and said monitoring-and-control unit and the segment of computer bus on the other hand, and - a support structure, on which the protection unit, the segment of computer bus, each monitoring-and-control units, each input-output modules and each external connection modules are fixed, in that the height of the monitoring-and-control units can be equal to 1U, 2U, 3U, 4U, 5U or 6U, "U" designating a unit height corresponding to a base height of a monitoring-and-control units, and in that the functional module has a main height equal to 6U and can accommodate any technically permissible combination of monitoring-and-control units, depending on the height of these control units, in practice between one and six control units. - one or more monitoring-and-control units, - a protection unit, common to all of the monitoring-and-control units, configured to supply electrical power to all of the monitoring-and-control units and to electrically protect all of the monitoring-and-control units, characterized in that the functional module also comprises: - a segment of computer bus, configured to connect all of the monitoring-and-control units to an industrial computer, - just as many external connection modules as there are monitoring-and-control units, each external connection module being configured to connect an electrical load which is outside the electrical connection enclosure to a monitoring-and-control unit and to supply electrical power to this electrical load from this monitoring-and-control unit, - just as many input-output modules as there are monitoring-and-control units, each input-output module being configured to connect the computer bus segment to a monitoring-and-control unit and to the electrical load connected to this monitoring-and-control unit and to allow the exchange of operating data between said electrical load on the one hand and said monitoring-and-control unit and the segment of computer bus on the other hand, and - a support structure, on which the protection unit, the segment of computer bus, each monitoring-and-control units, each input-output modules and each external connection modules are fixed, - a segment of computer bus, configured to connect all of the monitoring-and-control units to an industrial computer, - just as many external connection modules as there are monitoring-and-control units, each external connection module being configured to connect an electrical load which is outside the electrical connection enclosure to a monitoring-and-control unit and to supply electrical power to this electrical load from this monitoring-and-control unit, - just as many input-output modules as there are monitoring-and-control units, each input-output module being configured to connect the computer bus segment to a monitoring-and-control unit and to the electrical load connected to this monitoring-and-control unit and to allow the exchange of operating data between said electrical load on the one hand and said monitoring-and-control unit and the segment of computer bus on the other hand, and - a support structure, on which the protection unit, the segment of computer bus, each monitoring-and-control units, each input-output modules and each external connection modules are fixed, in that the height of the monitoring-and-control units can be equal to 1U, 2U, 3U, 4U, 5U or 6U, "U" designating a unit height corresponding to a base height of a monitoring-and-control units, and in that the functional module has a main height equal to 6U and can accommodate any technically permissible combination of monitoring-and-control units, depending on the height of these control units, in practice between one and six control units.