Basic elements of electrical installations

In buildings supplied directly from transformer stations located within these buildings, Bays of LV switchgears of the substation can be used as connectors.

The basic elements of electrical installations are:
— electrical wires and cables,
— switchgear,
— electrical installation equipment and fittings.

There are three ways of arranging electrical installations in buildings: under the plaster, in plaster and in plaster.

Installations under plaster are laid in electrical installation pipes. These pipes are placed in appropriate grooves made in the walls and ceilings - in the case of buildings erected using traditional methods or embedded in the structural elements of the building - in the case of buildings made of prefabricated panels or erected in monolithic technology.

Plaster installations are made with the use of flat multi-core cables (recessed) and covered with plaster, which is a fastening element for cables and protects them against mechanical damage. The thickness of the plaster layer covering the wires should be at least 5 Mm. The recessed installations are only used in dry rooms.

Cables in installations on plaster can be laid in pipes or electrical installation strips or without any cover. Without the cover, only indoor cables are laid on the plaster, in which there is no risk of mechanical damage. Plaster installations are mainly performed indoors, in which aesthetic considerations do not play a role.

Cores of cables used in electrical installations in buildings, with a cross-section to 10 mm2 should be copper. All circuits should have a PE conductor separate from the neutral conductor N (system of TN-S network). Receiving circuits should be protected with overload circuit breakers. As protection against electric shock, an automatic switch-off with overcurrent protections or residual current devices should be used..