Re: Contemplating house rewiring - advice?

[Kevin Hawkins <yahoogroupskh@xxxxxxxxxxxxxx>]

James, like Paul I really do recommend you star wire now if possible
as
it saves so much hassle and cost later when the HA bug bites.  If done
correctly you can easily revert a home to normal operation when you sell
, all from the consumer unit.  There's a really good info on the group
associated website re wiring if you haven't already seen it ....

http://www.automatedhome.co.uk/content/wiring-guide.html

Just one addition to Paul's comment below..Assuming you just star wire 1
cable of twin and earth  to the switch then you will not have a problem
if your HA switch replacement requires switched live, neutral and
earth.  Although not often encountered if you install anything  that
requires live, switched live,  netural and earth then you will need to
install three core + earth.    Some fancier switches with displays /
indicators need this.

In some places where I retrofitted star wiring I compromised  a little
by bringing 3 core + E back from each ceiling rose which effectively
picks up the switched live from existing switches - allowing you to
automate but retain the existing mains switches. Even on/off switches
can be utilised as toggles this way.   You can also revert to standard
wiring for when you sell, just by looping back at the consumer unit.   I
would dearly have liked complete star wiring for all lights and switches
but in some places  the consequential mess would have ensured no family
lineage.

Re CAT5 if you put that in too, which you should,  then do ensure that
it is not run adjacent and parallel  to mains wiring as this induces
interference into the signalling.  C-Bus pink CAT5 is not screened. Try
and cross mains/CAT5 cable runs at right angles if possible and with as
much separation  as possible.   You can never have enough spare CAT5 in
a home if you get hooked on HA as it's now used for so many other things
aside from Ethernet.  Run extra cables to each room, particularly if
later access will be difficult. CAT5 isn't expensive so leave it coiled
up under floorboards or something, and label the ends.   You don't need
mains rated CAT5 like the C-Bus pink if it's separated from mains
wiring. In commercial buildings I believe you need Plenum sheathing
though for fire safety compliance.    Using different colours for
functionality is always helpful e.g. identifying Ethernet, IDRANet,
C-Bus, , EIB/KNX, audio, video,  telephone, RS232/485 etc...

BTW Some twisted pair (e.g.CAT5) bus topologies work with star wiring
but some do require a single run or even a loop.  This might mean
running two CAT5 to each point - or you might get away with looping back
within the same CAT5 over small distances.   In one really awkward place
in my home I tried to pass C-Bus and IDRANet down different pairs within
the same 25m run of CAT5 but that didn't work.

Increasingly endpoint devices are POE (power over Ethernet) capable and
in a home with several devices this is best serviced by one central POE
Ethernet switch and star wiring.  Helps cull the wall warts- one of my
pet hates.     If you don't have sufficient cabling available then 3COM
/ HP make some really small web managed POE network switches that can be
neatly attached to a wall to expand Ethernet ports should you need a few
extra in a particular room. . Available in 4+ port 100Mbps and Gigabit
versions, they also helpfully offer a pass through RJ45 for non Ethernet
(e.g. phone, C-Bus/IDRANet  or AV use).   I ended up using a lot of the
3CNJ225 100Mbps ones as they are really cost effective if you buy
carefully  ~ £25 for a web managed POE powered switch !  They
just mount
onto a standard UK single socket back box and provide 4 ports - one even
offering POE forwarding plus the additional RJ45 pass through.  BTW  I
have some of these spare still if anyone is in need of any...


K

On 25/11/2012 09:49, Paul Gordon wrote:
> Which of course is easy to reconfigure IF you star wire everything...
- you can just make the appropriate connections back at the consumer
unit...
>
> :-)
>
>
> -----Original Message-----
> From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of James
- SJ Computers
> Sent: 24 November 2012 20:09
> To: ukha_d@xxxxxxx
> Subject: Re: [ukha_d] Contemplating house rewiring - advice?
>
> All lighting circuits do require a neutral (they wouldn't work if they
didn't have one). A standard ceiling rose has a loop in / loop out for both
line and neutral.
>
> Standard lighting control (1/2 way / intermediate switches) don't have
a neutral as such. In domestic wiring you'd drop a standard bit of twin and
earth to the switch and utilise the neural of the pair as a switched live,
and sheath it accordingly, of course.
>
> Regards
>
> James
>
> Sent from my iPhone
>
> On 24 Nov 2012, at 17:59, "Alan Middleton"
<yahoo@xxxxxxx> wrote:
>
>> I thought most HA lighting systems required a neutral which isn't
the norm in UK lighting. If that is true (and I'm not 100% sure) I'd
concider rewiring with one present.
>>
>> ----- Start Original Message -----
>> Sent: Sat, 24 Nov 2012 14:06:24 +0000
>> From: James Reed <james@xxxxxxx>
>> To: ukha_d@xxxxxxx
>> Subject: Re: [ukha_d] Contemplating house rewiring - advice?
>>
>>> Thanks Paul, this is very helpful.
>>>
>>> I can see that the star wiring may be problematic, particulary
>>> trying to explain it all to SWMBO when there will be higher
costs etc.
>>>
>>> I will pursue the pink CAT5 idea as you suggest. So far as
topology
>>> goes, I guess the idea would be to terminate as much as
possible of
>>> it in a single place, but again thinking about aesthetics
could you
>>> have nodes at each floor with links between them? I read the
Idratek
>>> wiring guidance which seemed to suggest such a thing might be
>>> possible. Again I want to try and put it in a way which makes
it
>>> easy for the sparks to follow as I imagine they won't have
much experience of this sort of thing.
>>>
>>> James
>>>
>>> On 24/11/2012 1:11 pm, Paul Gordon wrote:
>>>> Yup, you've answered your own question pretty well
James...
>>>>
>>>> To give yourself the utmost flexibility in your future
selection
>>>> of what system to go for, if you both star-wire the mains
cable
>>>> *and* run some control cable into each backbox as well, I
think
>>>> you've pretty much allowed for any possibility.. and even
if you
>>>> end up not using one or other cable, at least you have not
limited
>>>> your options in any way, and cable is - comparatively -
cheap..
>>>> (compared the HA modules you will eventually connect to
them!)
>>>>
>>>> Couple of thoughts..
>>>>
>>>> Star wiring the mains isn't the "norm" in the
UK, so your sparkies
>>>> may be resistant to the idea... it will increase cable
costs -
>>>> both in that you will use more of it - the ring main
topology was
>>>> thought up to minimise the quantity of cable required I
believe, -
>>>> and I think you have to uprate the mains cable you use...
- your
>>>> sparks should know about that assuming they know their
onions...
>>>>
>>>> For control cable, even though you seem to have rejected
CBUS for
>>>> now, you would still get benefit from using CBUS's pink
CAT5 cable
>>>> as your control wiring.. - it's not specific to CBUS -
it's just
>>>> bog standard CAT5 cable on the inside, - but the pink
outer sheath
>>>> is certified mains rated, so you are allowed within the UK
wiring
>>>> regs to bring that cable into the same enclosure where
mains is
>>>> present... - that is not permitted with
"ordinary"
>>>> computer CAT5 cable - which can be obtained quite a bit
cheaper...
>>>>
>>>> CAT5 cable at each socket and switch backbox shoud cate
for just
>>>> about any wired HA system, although I believe there are a
few
>>>> options available that require the use of their own
proprietary
>>>> control cable.. personally I wouldn't give consideration
to any HA
>>>> system that imposes that demand, but that's just me... -
for me,
>>>> if CAT5 isn't good enough, then I'm not giving that system
my money...
>>>>
>>>> Paul G.
>>>>
>>>> -----Original Message-----
>>>> From: ukha_d@xxxxxxx <mailto:ukha_d%40yahoogroups.com>
>>>> [mailto:ukha_d@xxxxxxx <mailto:ukha_d%40yahoogroups.com>]
>>>> On Behalf Of James Reed
>>>> Sent: 23 November 2012 20:00
>>>> To: UKHA_D Group
>>>> Subject: [ukha_d] Contemplating house rewiring - advice?
>>>>
>>>> Hi
>>>>
>>>> I've just moved in to a largish victorian terrace. The
wiring is
>>>> not in good condition, and as we are planning to stay for
some
>>>> time I'm contemplating having the whole house rewired.
>>>>
>>>> I'm keen on home automation but haven't really got the
money (or
>>>> the permission from HQ!) to install all the modules etc
now. I'm
>>>> interested in a wired system such as Idratek (have looked
at Cbus
>>>> but seems too expensive by comparison).
>>>>
>>>> I've got some electricians coming round, and basically
what I am
>>>> asking is what sort of wiring would I need to give me
options in
>>>> the future to add kit bit by bit? I was thinking that I
would need
>>>> control wires run along with the mains cabling for the
lights at
>>>> least - any suggestions how?
>>>>
>>>> ALso should I be considering 'star wiring' of the lighting
circuits?
>>>>
>>>> What I'm trying to balance up is making the most of the
>>>> opportunities presented by a rewiring whilst keeping costs
as low
>>>> as I can. I'm going to have a number of years of leisure
to
>>>> install modules etc, but
>>>> (hopefully!) only one shot at the rewiring.
>>>>
>>>> I'd be really interested to hear views / opinions
>>>>
>>>> James
>>>>
>>>> ------------------------------------
>>>>
>>>> Yahoo! Groups Links
>>>>
>>>>
>>>
>>>
>>> [Non-text portions of this message have been removed]
>>>
>>>
>>>
>>> ------------------------------------
>>>
>>>
>>> Yahoo! Groups Links
>>>
>>>
>>>
>>>
>> ----- End Original Message -----
>>
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