The low voltage electrical system user according to CEI 64-8, is defined as "the set of electrical components electrically associated in order to meet specific purposes and coordinated with similar characteristics. Part of the electrical all electrical components not supplied by plug sockets, are also part of the electrical appliances fixed powered plug sockets intended solely for their food. " In fact, the electric system is the system user that usually includes distribution channels, the terminal circuits, protective equipment, cutting and command, control panels, the plug sockets for connecting mobile users. Again with reference to IEC 64-8, art. 132.1 provides that the electrical installations must ensure that:

The above is accomplished through careful design and proper installation, which provides, inter alia, the use of quality products and fully comply with relevant standards and / or certifications. More precisely, the entry into force of Law 46/90 the skills of those involved (client, designer, installer) have been clearly defined. The buyer must contact an authorized designer and a regularly enrolled in their register. The project must be defined in all its parts and the designer is clearly involved for part of his responsibility.

The Law 46/90 has been replaced by Ministerial Decree 37 of 22 January 2008 (OJ No 61 of 12.03.2008) and the DL June 25, 2008 No. 112 "Regulations on the introduction quaterdecies Article 11, paragraph 13, letter a) of Law No 248 2 December 2005 laying down provisions for the reorganization of the activities of installation of the equipment inside of buildings "and this shall identify individuals qualified to design and manufacture the main types of facilities for all the buildings and what obligations and requirements should follow these subjects. Fundamental in the design, implementation and testing of an electrical system are the rules of the Italian Electrotechnical Committee (IEC): the electrical low voltage supplied by a body elettrocommerciale must include a grounding system (TT) as required for protection against indirect contacts. A successful design must comply with IEC Guide 0-2 indicates that, depending on the type of electrical equipment, project documentation required. In electrical breakdowns and malfunctions may occur, for example short circuits, overloads, dispersions. To prevent these events produce injury to persons or things to be installed proper protective equipment, such as::

These protections are also very useful to prevent the onset of fire and electrocution of people due to direct contact or indirect contact with live parts.