Pre-wiring C-Bus in a new house build...?

Discussion in 'General Discussion' started by fo0l, Nov 9, 2009.

  1. fo0l

    fo0l

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    Howdy, first time poster. Building a new two-storey house and am pretty keen on getting it prepped for some level of home automation with the ability to expand the system later.
    I got some info from one crowd who told me they could pre-wire by running cable everywhere in the house. Another crowd told me that pre-wiring wasn't an option because of the way C-Bus worked.
    What I'm stuck on is whether or not its possible to wire conventionally and pre-run the C-Bus cable. Then later, replace the switch with a C-Bus switch, hook it up to the C-Bus cable and join the conventional cables which can then be hidden back in the wall?
    Obviously this would mean not every light in a room might not have an individual home-run which would mean 'limited' control of a rooms lighting etc however this seems like a logical option.
    Ideally I'll have the living areas, master, media and security on the system up-front but as with most mere mortals am mindful of budget so would prefer to expand the system easily later.
    It seems strange I've not found much information about partial, scaleable installations without going wireless - which surely has its own limitations (not my fave idea...)
    Any experiences and advice appreciated! :confused: :D
     
    fo0l, Nov 9, 2009
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  2. fo0l

    froop

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    First up, a disclaimer. I'm not an electrician nor a C-Bus expert or professional. Just a keen (and somewhat knowledgeable) DIY HA hobbyist with C-Bus :)

    The simple answer to your question is "No". If you want C-Bus, you really need to commit all or nothing from the get go. There's all sorts of difficulties to deal with. For a start, you want to keep the Cbus cable separate as much as possible from 240V. And if you're reconnecting and shoving your wires back in behind a cbus switch you've got yourself the weakest link of the 240V (where its joined) sitting right next to the back of your cbus switch.

    Then where you've got a switch plate with 2,4 or 6 switches, with traditional wiring you've got one source into the switch plate going off to the individual lights. To pre-wire with Cbus, you'll need 6 wires in and six wires out to retrofit.

    The only half pratical way that I can think of is if your building allows easy access through the roof cavity to each wiring crcuit. That way you can pre-wire the C-Bus cable, but when you want to actually switch over to Cbus, you pull out the old cable, and re-wire with home runs.

    If you're trying to save cash on the outlay, it won't really work. Even if you can figure out the wiring logistics, it'll likely end up more expensive in the long run.

    If saving money at the start is what you're concerned with, why not instead get all the wiring done, but see if you can save elsewhere. Maybe instead of buying 3x8 channel dimmers for 24 lights, buy 2x12 ch relays. Or wire your bathroom light with the extractor fan to save a relay channel (or two if you have two bathrooms). Use 2000 series switches instead of saturns or neos. Or it might work out well if you get a wireless gateway and a remote control and leave out a handful of less-used switches.
     
    froop, Nov 9, 2009
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  3. fo0l

    znelbok

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    Well I reckon you can pre-wire for C-bus

    I would design the house as a -Bus install first and then look at taking it backwards to a standard house.

    There are two possible methods of wiring.
    - home run all light circuits
    - home run only switch wire

    The former gives ultimate flexibility e.g. should you decide to change something from a relay to a dimmer.

    The latter is a little cleaner and cheaper.

    To pre-wire for C-Bus in the latter is easiest. Install it as you would for C-Bus, have the board in place and all circuit breakers installed etc.
    Have all y our lights assigned to dimmers/relays and then group them on the RCD's accordingly.

    You need to install the switch wire for C-Bus, but you also want one for the standard light switch (which you will pull out later if you can). When you are ready to upgrade, you need to do all the lights for a dimmer/relay at once.

    You can do the other way quite easily as well, but in both cases you really need to fully understand the design and then how to bring it backwards.

    My suggestion would be, just bite the bullet and go for it. You wont regret it and once you are in you wont miss the extra money you spent.

    Mick
     
    znelbok, Nov 10, 2009
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  4. fo0l

    fo0l

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    cheers guys!
    appreciate the input, i'm still researching and asking stoopid questions all over the show.
    no doubt some of them will end up back on here! :D
     
    fo0l, Nov 12, 2009
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  5. fo0l

    daky

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    It is quite common for people to enquire about Pre-Wire for Cbus and reasonable question because of initial buiding costs that many customers have.

    My suggestion is to design the wiring for cbus and install the most important but minimal hardware required for the job with provision for future expansion - such as space allowances for future relays and dimmers and cable runs additianl hardware. tps cables can be pulled if allowed for initially.
     
    daky, Nov 13, 2009
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  6. fo0l

    fo0l

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    hey all, thanks for taking the time to read and reply - much appreciated. i've done a lot of reading and researching (as you do!) and will be making a decision on how to proceed within the next few days. at this point its leaning towards a partial c-bus install with pre-wire to the 'less important' areas. ideally this will result in control around the living/dining/kitchen areas, perhaps the master bedroom and media-room. the rest can wait at this stage. again, thanks for your input - no doubt i'll be floating around these boards more in the future if the bug truely bites! cheer! :D
     
    fo0l, Nov 15, 2009
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  7. fo0l

    industeq

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    There is a way to pre-wire in a high voltage then change over to the low voltage C-Bus later.
    I did on our recent install and here is how to do.
    Run all the wall boxes in ENT conduit ( Blue flexible tube) as a home run.
    The blue ENT conduit is readily available at large home improvement stores.
    http://www.carlon.com/Master Catalog/ENT_2B43.pdf

    Then you can wire all lighting fixtures as a home run / high voltage back to the electric panel.
    I did this on a new construction as I was un-sure how the city inspector would cite for code. All was OK and passed once explained my intention.
    With is route I could either wire as a standard circuit (with extra wire of course) or pull the pink C-Bus wiring to my wall switches.
    It worked great and room for expandability as it is piped and can add more wires if needed.
    Grant it, I am in the USA so the electric code is different across the pond but I would consult with the builder and electrician on options.



    Regards
    Alan Dobbs
    Industeq, Inc.
     
    industeq, Nov 16, 2009
    #7
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