Chapter 8: Things to avoid

Daisy chain telephone

Yes, you can save wire by installing phone lines the “old fashioned way” and simply string a single wire from room to room, but don’t be fooled. A “Home-Run” installation with each room running all the way back to the media cabinet has huge benefits. It works better with DSL installations, it allows the use of any wire for Data or other applications if you need it, and troubleshooting a faulty wire is much easier.

Share neutral for ceiling fans

A typical ceiling light fed from a switch uses a 2 wire + ground romex cable (14-2 or 12-2 i.e. black, white and bare). If you later decide to install a ceiling fan in that room, the typical installation is to put a dual switch next to the door – one for the light and one for the fan. The temptation is to use the same wire running up to the fan to run both circuits hijacking the black for light, white for fan and bare for neutral leaving off the safety ground altogether. Will it work? Yes, Is it safe? Absolutely not. You have three choices:

At the fan location connect the light and fan “black” wires together so the single existing switch controls both. Individual control is then done through the pullchains
Install a digital switch specifically for this application. For about $40 you get a wall switch with both light and fan controls and a receiver that is hidden in the wiring box of the fan. It allows a single power line to dole out electricity to either circuit on command of the wall switch. Wireless options are also available
Pull a new wire – 3 conductor (Black, Red, white plus bare safety ground) between the switch and the fan

Share Ethernet and phone

Only have a single CatX wire to a room and you need both data and phone? 10MB Ethernet uses only 4 wires and telephone uses 2 so theoretically you can connect both services to the same cable and split them back out at each end into the proper RJ11 and RJ45 jacks. Can you make it work? Yes. But consider the issues:

100MB and Gigabit needs all 8 wires. If you use some for another service you are eternally stuck with a slow data connection.
Data connections are low voltage, telephone uses 48V DC plus another 90V on top of that when the phone rings. If the wires ever short or get crossed you are putting 140V peak into an Ethernet jack and the vast majority will fry.
If there is significant activity on the phone line or during any ring, the data connection is likely to disconnect or corrupt data. Keep in mind there is no shield of any kind between wire pairs – only the insulation around the wire itself

Only one more chapter to go in this feature – it will be in our next eMagazine issue so stay tuned.

Appendix A: Links to sources, references, and products:
Other good how-to and pre-wire guides: Crutchfield on multiroom systems Prewiring basics from smarthome remote control systems from crutchfield home tech solutions whole home audio intro. There are some more detailed speaker placement guidelines and some good ideas for combining home theater and whole-home audio/video room/plans. Xantech IR training powerpoints
Products referenced in this guide: Baluns – single Cat5 for component plus digital audio A review of the Russound C5 by CEPro The Russound C-series (Search on internet for good direct pricing) Niles audio products – multizone systems, multizone amps, wall controls etc. The main nuvo website with a nice selection of systems HDMI cable specifically made for pulling through conduit – circular pull off ends. BOCS Whole-Home Audio/Video distribution over COAX

With 20 years in the Consumer Electronics space, David pioneered wireless LAN for home use in partnership with Linksys, rotating storage for portable electronics at Cornice, and is most recently a founder and chief marketing officer of BOCS Inc, the manufacturer of a new whole home A/V distribution system for retrofit applications