Glossary
PoE (Power over Ethernet, alimentación por cable de red)
Power over Ethernet: technology that sends electrical power and data down the same network cable. It lets you install IP cameras, wifi access points or video door entry panels with no socket nearby, powered by a PoE switch or injector.
What PoE is
PoE, short for Power over Ethernet, is a way of powering devices through the same network cable that carries their data. A single cable with an RJ45 plug is enough to run a camera or an access point, with no socket next to it.
How it works
The power is injected by a PoE switch, which feeds all its ports, or by an injector placed between a normal switch and the device. Both negotiate with the connected equipment how much power it needs before supplying it, so devices that are not PoE are not damaged. The voltage is low, around 48 V DC.
Standards and power
The IEEE 802.3af, 802.3at and 802.3bt standards define different power levels per port, from about 15 W on the most basic to about 90 W on the latest. Before buying, check that the switch delivers the power your devices need and that the total does not exceed its power budget.
What it is used for
- IP security cameras on façades, in garages or on ceilings.
- Wifi access points on ceilings, where there are no sockets.
- IP video door entry and access control.
- IP phones in offices.
- Sensors and small smart home devices.
Advantages and limits
- One cable and less building work.
- Central power: put a UPS on the switch and cameras and wifi keep working during a power cut (outage).
- Distance: as with any ethernet cable, a run must not exceed 100 metres.
- Poor quality or very thin cable increases voltage drop and heat.
How we help
We design the network, choose the switch and run cable of the right category. See CCTV installation in Seville, Spain.
Related services
CCTV video surveillance
For CCTV installation in Seville, Spain we propose the system you actually need: IP cameras with a recorder, viewing from your phone and the information sign that Spanish data protection law requires, in homes, villas, building entrances, communal garages and businesses. Clean cabling and cameras aimed so they do not record the public street.
Data networks and structured cabling
We install structured data cabling in Seville, Spain for homes, offices and warehouses: Category 6 or 6A network cable, RJ45 sockets, a rack cabinet and patch panel, plus wifi access points so coverage reaches every floor. A stable wired network for working from home, streaming TV or connecting security cameras.
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.