CAT6 cable separation from electrical
jbarrish
| Posted in Construction Techniques on
My home is currently in the rough-in phase, (framed, plumbing, electrical, HVAC all done), and I now want to install computer network cabling throughout. My question is what is the distance I should keep the network cable away from the electrical cable to prevent any interference, static, etc.). Its so tempting to share the power line route and run through the same bore holes, but I suspect I’m asking for trouble if I do so. Any references, websites would also be appreciated!
Thanks for any advice!
Julio
Replies
From http://www.connectedhomemag.com/Networking/Articles/Index.cfm?ArticleID=24765
"You should consider several factors when determining how each cable run will get from point to point. Avoid running cable near electrical wiring. If you must cross electrical wiring, make the network cable cross perpendicular to the wiring to minimize crosstalk and interference, which degrade network performance. Route Cat 5 cables several feet away from fluorescent lighting fixtures where possible for the same reason. Secure cables with wire hangers, wire ties, or wire staples. If you buy a rack to hold the hub and patch panel, use wire ties to bind cables to the rack and relieve strain on the connections to the hub. If using wire staples, be careful not to run the staples through the cable. You don't need to run Cat 5 cables through conduit, and network cables can run as a bundle without concern for crosstalk between them. Don't run Cat 5 cable through ventilation ducts; the cable insulating sheath gives off toxic fumes if it gets hot enough to burn."
The minimum distance I recall to keep between paralell low and high-voltage wiring bundles is 6 inches, though 16+ inches (i.e. at least one stud bay over) is what I use. Running wiring through the same holes as the electrical is thus not possible. On one DIY job I did in ME, I used lots of Great Stuff to foam all the stud holes shut after passing Cat5, telco, and coax wires through them. The electrician was not pleased because that meant he had to drill his own holes for the high-voltage stuff, but it also kept the network safe from interference.Also, you can run low-voltage wiring in air ducts, but only if it is PLENUM rated, IIRC. Such wiring usually commands quite a premium but is common in some forms of construction.
The real problem with running LV wiring in ducts is the rattle.
Yup, and the interference these wires (in sufficient quantity) can pose to proper air-flow and zone dampers.
I dont think the nec allows it in ducts evan with plenum cable.If it where me I would run conduit to all locations then back to your "wiring closet" that way your future proffed if you should find you need a addtinal cable or a diffrent type (like fiber ) it would be no problem in adding it. 6" min from electric but we try for 12" being close wont cuase static but can cause data problems from RF
You're right, now that I think of it. Plenum is probably not rated for use inside ducts, rather it is rated for usage in the plenum space above dropped ceilings and the like in office buildings. However, IIRC, some office building designs have used plenum air spaces to help move air, as that was implicated in at least one "sick building" locally. Given the cost of running wiring (in terms of labor) vs. the cost of installing structured wiring, I'd always opt for the more expensive structured wiring and install the (2x CAT5e, 2x RG6, 2xMM fiber) bundles. Oodles of bandwidth... You don't even have to install the fiber plugs initially... simply leave the fiber in the wall and install the plugs / terminal jacks as needed later on.
Yes, six inches is a good rule of thumb. Being closer for a bit generally won't hurt (and, from an interference point of view, you could easily get away with occasionally running power wiring and CAT6 through the same hole), but on extended parallel runs you want to keep them apart.