Your electrical installation at home. Tips to change it

The first thing you must take into account when changing your electrical installation is safety. Manipulating your installation in any way must be supported by some strict protocols to prevent accidents. For that reason, we recommend contacting an expert.

You can hire a professional and entirely remove yourself from the equation. Or you can understand the basics of the process to supervise what the specialised technician will do.

Step 1: cut the power

Before touching anything, you must cut the entire home’s electrical supply. Look for the general switch on your electrical panel and switch it off. Next, check that there is no current by turning several switches off and on.

Any professional must take this into account, but just in case, it’s best for you to know about two essential premises and make sure they are fulfilled:

1. Respect the Electrotechnical Regulation for Low Voltage at all times, which offers a framework of technical conditions.
2. Only use approved tools and products.

Step 2: draw out the design

Once safety has been guaranteed, it’s time to pick up a pencil and paper. Draw a blueprint of your home, room by room, without skipping the details. Grid paper is recommended. You’ll also need a tape measure to know the exact dimensions of each wall and each space.

Once you’ve finished a blueprint that corresponds to reality, you must include the lights, plugs and switches. Don’t forget any of the existing ones and think wisely about those you want to add. Take into account where the furniture will go, where natural light enters, etc.

When you finish the sketch, check it again before taking coloured pencils and connecting each plug to each other:

• Use one colour to connect the plugs with the least resistance (10 amperes), which will be those that use less power (lamps, cell phone chargers, alarm clocks, etc.).
• Use another colour to connect the plugs with medium resistance (16 amperes), which will be those corresponding to electric radiators, for example.
• Finally, use a different colour that connects the plugs with the most resistance (25 amperes), which will be for the home appliances with the most power. The washing machine, refrigerator, dishwasher, air conditioning apparatuses...will be connected to these plugs.

When you’re finished connecting the plugs to each other, extend all of the lines to reach the electrical panel. This is where the protection and control elements of the electrical installation will be concentrated.

The electrical panel generally has the AMS (Automatic Main Switch), which disconnects by itself to avoid short circuiting. You’ll also see the DS (Differential Switch), that shuts off when an escape current is generated. Finally, the panel has several automatic switches that control several elements or zones of the home to avoid overloads and short circuiting.

The idea is to concentrate the plugs with the least resistance into one single automatic switch. On the contrary, for the kitchen, we recommend you install several automatic switches (for example: one for the oven and stove, another for the washing machine and dishwasher, another for the refrigerator, etc.). Both the heater and air conditioner must each have their own corresponding automatic switch.

Step 3: execute the plan

Once you have everything planned out, you must start to make decisions. If you want the wiring to be built-in (inside the walls), you must do some remodelling and painting. If on the other hand, you decide that the cables will be on the outside, you’ll have to install chutes that cover the cables for aesthetic and safety reasons. You can use false ceilings, baseboards or skirting as decorative solutions.

Also remember that when choosing the cables, there is a classification for insulation (that you’ll be able to verify by looking at the colour of the cable). If you prefer superficial wiring, take into account that flexible cables are more versatile for adapting to corners. Finally, don’t forget that all of the plugs must be connected to the phase conductor (black, brown or grey cable), to the neutral (blue cable) and to the junction box (or earth connection).

To finish, you must install the switches and plugs. The switches are generally placed 110 centimetres from the ground and the plugs between 20 and 30 centimetres from the ground. Some plugs, like those for night stands, the bathroom or kitchen, must be at different heights, given that they will serve to connect to different devices.

“Plugs should be 20-30 centimetres from the ground. Switches should be approximately 110 centimetres above the ground.”