Re: How would YOU approach this HA task?

["ben_mccormack2000" <yahoogroup@xxxxxxxxxxxxxxxxxxx>]

Paul

Have you considered the cbus t-stats? If you move then just replace them.

Ben

--- In ukha_d@xxxxxxx, Paul Gordon <paul_gordon@...> wrote:
>
> Peeps, (sorry this is a bit long & rambling!)
>
>
>
> I've just had a new central heating boiler fitted (actually finished
> commissioning at 22:45 last night!) - The programming electronics
haven't
> been fitted yet, - another engineer is coming tonight to fit the
> timer/programmer, and the T-stat.
>
>
>
> Obviously this is an *ideal* opportunity to bring the heating under HA
> control, - but my question is how best to implement the combination of
the
> "native" plus the HA control?
>
>
>
> I'd like it to operate fully under the HA system control for
"normal
> operation"- i.e. I'll do all the heating on/off time programming
in the HA
> system, - either by Comfort timed events, or perhaps with some CBUS
WISER
> code... and not, under normal circumstances, to use the onboard time
> programmer within the boiler... however, I'd like to have that onboard
> programmer still available to return to "traditional" (i.e.
non automated)
> operation in the event that some failure occurs with the HA, - or I
decide
> to sell up & move out...
>
>
>
> This part is fairly simple, I've identified the connection points on
the
> control board, - there are basically a single pair of terminals, -
currently
> bridged with a link wire which is removed when any kind of controller
is
> used, so that's obviously where I'll be connecting my CBUS relay...
>
>
>
> The questions I'm mulling over just now, are how best to arrange the
wiring
> connections?..
>
>
>
> With only a single terminal pair - i.e. only 1 "input" to
the boiler via
> which any external controller can call for heating demand, should I
bring
> that connection outside the boiler, or should I run my CBUS relay
> connections into the boiler casing and double-up in the existing
on-PCB
> terminal block? - obviously bringing it outside to an easily
accessible
> terminal block would be more flexible (but the fitter may balk at that
> idea?)
>
>
>
> Secondly, should I just parallel up the onboard controller & my HA
> controller? - doing so allows either to call for heating, - of course
if one
> of them is calling for heating, the other can't turn it off, - but I'd
be
> planning to leave the onboard controller "disabled" - either
by not actually
> programming any "on" times, or by programming it as normal,
then leaving it
> in an off rather than a run state if possible (my old boiler timer
allowed
> this) - using the 2nd way the onboard timer will have a program in it
ready
> to run at the flick of a switch, but in normal use won't actually be
running
> that time program & thus won't ever call for heat, so my HA system
will have
> complete control over the heat demand...
>
>
>
> OR, would it be better to connect up the two alternative external
control
> systems via a 2-way switch, so that the control could be via *either*
the
> internal timer, *or* my HA system, but never both. - Choice would be
set by
> a user-settable switch adjacent to the boiler (although I guess that
could
> be automated as well)...
>
>
>
> Lastly, and perhaps my biggest quandary, is how best to implement the
> T-Stat?... - AFAICT, the traditional way of doing this would be that
the
> onboard timer and the external room T-stat would connect in series
into the
> demand terminals, so that *both* devices had to be calling for heat
before
> the boiler would fire... given the choices highlighted above, I can
only
> envisage a means whereby the T-Stat would be integrated with either
the
> onboard timeclock OR the HA system, but not both... - perhaps I could
> engineer some kind of double-pole changeover so that if I implemented
the
> "either-or" model described above where a manual switch is
used to select
> the "active" control system, this could also switch the
T-Stat over into the
> wiring for that system?
>
> The other possibility I can envisage involves using two separate
T-Stats,
> but that could be confusing for an end-user, since only 1 of them
would
> actually have any effect on the heating demand, so then how I decide
where
> to position them? (so I really don't like the 2 T-Stats idea).
>
>
>
> FWIW, the T-Stat is wireless, - the boiler gets fitted with a receiver
> module, but apart from that the control wiring operates completely
> normally...
>
>
>
> So, how would *YOU* go about doing this?
>
>
>
> TIA
>
>
>
> Paul G.
>
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>




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