Glossary
Low voltage (baja tensión, BT)
The voltage range up to 1,000 V AC and 1,500 V DC, as defined by the Spanish Low Voltage Electrotechnical Regulations (REBT). It covers the 230 V of household sockets and the 400 V three-phase supply of shops and warehouses.
What baja tensión is
Baja tensión (low voltage) is the range in which almost every installation you use works: your home, the entrance hall, the corner shop or a warehouse on an industrial estate. The REBT, Royal Decree 842/2002, defines it as a nominal voltage of up to 1,000 V AC and up to 1,500 V DC.
Categories within low voltage
The regulations distinguish:
- Very low voltage: up to 50 V AC. Door entry systems, doorbells, 12 V pool lights.
- Usual voltage: 50 to 500 V AC. This includes the 230 V single-phase supply of a home and the 400 V three-phase supply of shops and warehouses.
- Special voltage: 500 to 1,000 V AC, for some industrial installations.
Above 1,000 V it is high voltage, with different regulations and different professionals.
What it covers
- The internal installation of homes and business premises.
- Communal installations in buildings: meter room, main supply line and individual riser cables.
- EV charging points, under ITC-BT-52.
- Solar self-consumption systems connected to the internal network.
- Outdoor lighting, pools, garages and industrial buildings.
Who may work on it
Only a registered low voltage electrical installer (empresa instaladora habilitada), entered in the regional register, may carry out these installations and issue the installation certificate, the boletín (CIE). A foreign qualification does not allow anyone to sign one in Spain. See electrical certificate (boletín) in Seville, Spain.
Related services
Electrical certificate (boletín)
The electrical certificate in Spain, known by everyone as the boletín and officially the CIE (certificado de instalación eléctrica), is the document a registered installer company signs to confirm that your installation meets the regulations. You need it to connect the electricity, increase your power or change the account holder with an old installation. We inspect, certify and register it with the Junta de Andalucía in Seville.
Industrial warehouses
We carry out the warehouse electrical installation in Seville, Spain and on its industrial estates: supply connection, switchboards, cable trays and conduits, power sockets, lighting, earthing and power for cold rooms, with project and legalisation. When the warehouse needs a transformer substation, we coordinate it.
Related questions
Need an electrician in Seville, Spain?
Call us or send a WhatsApp message with a photo of the job. You get a fixed quote before any work starts.