Remodeling my house and want to wire up each room with Ethernet/coax wall ports. Both Ethernet, coax and power will be running through the sub-floor.
I've read that there needs to be 2 feet between power cables and Ethernet to limit/prevent interference.
Is this true? If not, does anyone know what the distance is?
Best Answer
It seems that there is some truth to interference, but as far as I'm able to see, there is no real information available. There are some best practice tips and similar, but it all comes down to few things like: Use highest cable rating you can afford, use STP cable and 8P8C connector whose rating is same or higher than cable's rating. Be sure to use STP connectors with STP cables, or you'll get negative effects. If you can, use cables designed for outdoor installation, since they have better shielding. Make sure you don't bend cables too much. Bend radius should be 8 times outside diameter of the cable. Make sure that single cable is not longer than 90 meters (for main cable) + 2*5 m (for patch cables connecting the equipment).
As for power line interference, I couldn't find some concrete research. It appears to be affected by the clarity of the line signal, so anything which can cause disruptions such as some dimmers and similar devices can have negative effect. I've seen recommendations for distance to be form just 15 cm to nowhere near the power cables.
On the other hand, there are reports from people who used unshielded Ethernet cables near power cables and near devices which are well known to cause interference and who had no problems.
In the end, I'd recommend that you run a single cable in conditions of normal use and do some speed testing and decide if cable is a problem or not.
Here are some references I found: TechRepublic, Cables To Go, MetaFilter, LinuxQuestions, Pirate4x4, SooperArticles.