Power over Ethernet, or PoE, lets a single network cable carry both data and electrical power to a camera. That is why most professionally installed IP camera systems use it. There is no separate power outlet at each camera, and the cable run is simpler to install and maintain.
What PoE standards mean
PoE comes in several standards, and the power a switch can deliver per port depends on which one it supports.
- 802.3af (PoE): up to about 15 watts per port at the switch
- 802.3at (PoE+): up to about 30 watts per port
- 802.3bt (PoE++): up to about 60 or 90 watts per port
Most fixed cameras need well under 15 watts. Cameras with heaters, motorized zoom or built-in infrared lighting can need more, so check the camera specification instead of assuming.
The 100 metre rule
Standard Ethernet over copper cable is rated for a maximum of 100 metres (about 328 feet) from the switch to the camera. Longer runs need a network extender, fibre or a nearer switch location. Cable quality matters too. Use solid copper cable. Cheap copper-clad aluminum cable can fail to carry power reliably over distance.
Size the switch for the total load
A switch has a total PoE power budget as well as a per-port limit. A 16-port switch does not necessarily supply full power to every port at the same time. Add up the wattage of all the cameras you plan to connect, leave some headroom, and choose a switch that covers it.
Why it matters for reliability
Because the switch powers every camera, one battery backup or UPS at the equipment location can keep the whole system recording through a short power outage. That is much harder to do when every camera has its own wall adapter.
Our video surveillance and security camera services cover cabling, switches and recorders as one planned system.
Planning a project in Newmarket or the Greater Toronto Area? Contact Pitbull Security Solutions or call 888-963-5633 for a free consultation.