Cat 6 PoE parallel to power cables, just for 2 feet: What should I expect?

A question as seen posted to the StackExchange Home Improvement forum:

Preface: I don’t want to repeat the question already posed here.
I am a reasonably smart individual that does work around his house. I graduated with an EE degree way back when, so concepts of electricity are not foreign to me. I am aware of many of the reasons why one should not run Ethernet cable parallel to standard house power cable (magnetic induction causing interference, potential safety issues if both cables are punctured, code violations, etc).


All that being said, I am still asking this question and I wont hold it against you if you call me an idiot. 🙂


Situation: I am installing a Foscam weatherproof webcam just outside my garage. The camera supports PoE and I have a PoE router that it will connect to. I plan to connect the router and webcam using Cat6 Ethernet cable.


There just happens to be a motion sensor light just outside my garage. The motion sensor light consists of an junction box (exterior) and some Sch. 40 conduit that goes thru the exterior wall into the garage interior. This conduit leads to another junction box (interior) where power is routed from the house. The total wire distance between interior and exterior junction boxes is about 2 feet.


I want to avoid drilling more holes in my house. I am considering running my Cat6 cabling between the junction boxes (thru the conduit) and having it exit the exterior junction box. I would then hook it up to my webcam mounted close by. The Ethernet would only be parallel to the power cable for 2 feet of length (even though the actual Ethernet run would be much longer). Also the Ethernet would be within junction boxes and conduit the whole time it is together (increasing safety from random nails and such).


Question: I’m reasonably certain that there is enough shielding in the power and Ethernet cables to avoid a short between the two. However I am wondering how worried I should be about 2 feet of parallel run? Is that enough distance to have adverse effects? Also, if there is a constant inductance, how worried should I be about my PoE router and webcam being damaged over time?


Any and all speculation and empirical data is accepted. 🙂



Leave A Comment?