As part of a construction or renovation, the electrical installation is one of the longest and most complex finishing works. In order not to tangle the brushes during the works, it is strongly recommended to establish an electrical diagram from the start for all the details of the installation and its components.
What is an electrical diagram?
Presented in the form of a diagram or plan, the electrical diagram is made up of a series of universal symbols which precisely describe the installation. The electrical standard NFC 15-100 now requires the creation of this type of architectural plan which must be duplicated and given to the user. It is made up of a certain number of crucial data, in particular complete information on the safety systems, the intensity of the adjustment current, the electricity consumed by the various equipment, the plan of the cables, the number and the location of the different outputs, etc.
The creation of this electrical diagram is strongly recommended because it provides all the explanations and data on the equipment to be installed. In the case of a construction, this plan will help to define the budget necessary for the installation. Later, during maintenance or repair, the interested party will only have to refer to this document to carry out the work more easily. In principle, there are four types of electrical plans:
- Among the most common is the electrical diagram developed which is appreciated for the simplicity of the symbols used and the location of the devices. This plan has the advantage of avoiding wire crossings.
- Then comes the architectural diagram which provides a plan view of the house in which the various devices and appliances are located. In principle, this diagram is the work of a project manager or an architect.
- Using the same symbols as the architectural diagram, the third unifilar scheme shows a plan of the housing incorporating the various electrical conduits housing conductors.
- Last but not least: the multi-wire diagram generally used by professionals shows the routing of the wiring as well as the conductors. Very precise, this diagram also displays the number and nature of the wires.
When is the diagram essential?
Drawing up an electrical diagram is recommended when installing a lighting system operating by switch control. Taking into account the electrical plan of the house as well as the color codes is important for the installation. This begins with the junction box through which we take the red phase wire pointing to the switch and ensuring the cut. The bulb socket will be connected to the blue neutral wire. The red phase wire adopts a new color (black, brown or grey) as soon as it passes through the switch. The ideal is to choose a switch with indicator light when the latter is not in the room to be able to control the lighting and prevent it from turning on when you are no longer in the room.
This same system can be used for back-and-forth wiring. The neutral wires will therefore point towards the switch and the phase wire in the direction of the switch. Ditto, it is possible to use the technique to turn off a light point via two points. On the other hand, if there are more than two switches, it will be necessary to use a teleruptor.
When installing a dimmer, it is also advisable to draw up an electrical diagram. Allowing to modulate the lighting in several rooms of the house, this system requires a connection almost identical to that used with the switches. One of the two-way control buttons can be replaced by a dimmer. On the other hand, the wiring must be done in the rules.
The main families of electrical symbols to know to read an electrical plan
There are basically five main families of electrical symbols that you need to know well in order to be able to decode an electrical diagram.
Among the most important are electrical control symbols representing in particular switches, push buttons, dimmers or even key control systems.
Come next the symbols representing the lights including fluorescent strips, ceiling lights, spotlights or projectors.
Third, we find power outlet symbolsantenna or network and then those such as specialized circuits or equipment, to name only the refrigerator, hotplates, air conditioner or even heating.
There is also electrical equipment symbols and specialized circuits such as for the refrigerator, hood, washing machine or dishwasher…
Finally, there is various symbols representing for example a loudspeaker, a bell, an antenna or a remote switch.
Although simple at first glance, creating an electrical diagram requires the knowledge of a specialist. Its interpretation will become simpler and the execution of the work safer and faster.