RE: Fw: How would YOU approach this HA task?

[Paul Gordon <paul_gordon@xxxxxxxxxxx>]

Thanks Kevin. I think it shouldn't be too hard to maintain the onboard
timer
programs... - the whole onboard timer unit is modular, and includes an
on/off/timed selector switch, so it should hopefully be just a case of
flicking *that* rather than an extra external switch. (I hope so anyway,
because otherwise it's going to be difficult to contrive any kind of switch
arrangement between the timer unit & the boiler control board, since
being a
modular unit it connects directly to the board via some dedicated connector
no actual "wiring" is involved....

The research I've done so far is giving me cause for serious concern re the
CBUS T-stat units...

- They are configured to operate on the HVAC application, although it does
seem to be possible to change that to the lighting application (otherwise
I'd not have been able to "share" an existing relay module that I
just
happen to have 1 spare channel on)

- I'm not sure it's possible (still trying to find out) to adjust the
setpoint temperature remotely from other CBUS units - if so this is a
*major* shortcoming

- although it broadcasts the actual measured temperature on CBUS, it's not
entirely clear how useable that actually turns out to be for use in other
units...

- Worst of all, the forums are littered with dire warnings of the four
horses of the apocalypse descending to destroy the Earth if you even
*think*
about letting anything else other that the CBUS T-stat switch that relay
channel controlling the boiler... - this is an absolute showstopper if
true...

More research still required, but following my initial optimism regarding
these units, I'm now beginning to think that they might be a big fat waste
of time..

Paul G.


-----Original Message-----
From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of
Kevin Hawkins
Sent: 29 October 2010 12:13
To: ukha_d@xxxxxxx
Subject: Re: Fw: [ukha_d] How would YOU approach this HA task?

I would, if possible try and maintain the existing timer in a programmed
state and then switch it out by a plain old light switch arrangement
near the boiler.   Only because if the automation did ever fail for
whatever reason , and you weren't there,  then the family can just flick
the switch and it's all working again without having to set up the times
and including an advance /  24/7 override which I'm sure the timer will
have -  and employing the original thermostat.

Very interested to know how you get on with the C-Bus thermostats, I
keep meaning to have a play but I too find it quite a confusing option
range , especially as you introduce areas/zones.   Also quite
expensive.    Does anyone know.. if you get a unit with inbuilt relays
can you abandon these and use external C-Bus relays instead ?  I know
the internal relays are only controllable by the thermostat itself , and
not via C-Bus.

I've also seen a post where the C-Bus techies are very adamant you must
never externally override/control a relay that is assigned to a
thermostat -  which is I suppose something that I might have
intended...  but I suppose you get around this by controlling the
thermostat time override via C-Bus instead...

If you are using Comfort you might have to move the thermostats onto a
lighting application rather than the heating one, which I don't think is
detrimental feature wise,  it just reduces the application isolation.
Wiser though handles the heating app directly.

K

On 29/10/2010 10:16, Paul Gordon wrote:
> I think I'm leaning towards this as the simplest option...
>
> Leave the existing controls as they are, - for the timeclock I'll
> "de-program" any on times so that this never calls for heat.
I'll also
turn
> the existing wireless stat right down, so that also never calls for
heat...
> (although since it's in series with the timeclock that shouldn't
actually
> matter).
>
> Put a CBUS relay across the boiler's heat demand terminals (now
handily
> available outside the casing)
>
> Use a CBUS room stat to set the temperature (one of the relay-free
models)
>
> Therefore the existing controls are always available to be used if
required
> (just turn them up), but won't under normal circumstances
"interfere" with
> or "override" what the HA system want to set..
>
> "standard" end-user operation is maintained by setting a
knob on a
> "standard" looking room thermostat (WAF)
>
> Full control is available via any CBUS units, and therefore by
Comfort, -
> either of which I can use to set my heating schedule - I'll probably
go
for
> using Comfort to do this, since it has easily accessible scheduling
options
> for weekday/weekend operation, knows about sunset/sunrise times, knows
when
> all the UK public holidays are, and knows the occupancy status of the
> house...
>
> The temperature measured by the CBUS roomstat is available as a
datapoint
> for use in any other logic operations I might want to contrive, also
thus
> available to be displayed on WISER based touchsreens etc. (not sure
yet if
I
> can also get that variable through to Homeseer for use there...)
>
> Temperature setpoint can also be set remotely in addition to manually
> adjusting the roomstat knob... so Wiser touchscreens can also be used
as
> remote temp controllers as well as simple on/off..
>
> Easy-peasy!
>
> Paul G.
>
>
> -----Original Message-----
> From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of
> Paul Gordon
> Sent: 29 October 2010 09:01
> To: ukha_d@xxxxxxx
> Subject: RE: Fw: [ukha_d] How would YOU approach this HA task?
>
> Thanks, I'll take a look at that one...
>
> As it happens, the wireless receiver for the T-stat sits outside the
boiler
> casing anyway... the wiring arrangements for this require simply
bringing
> all the relevant connections out to a terminal block that forms the
> backplate of the receiver, so future access to change the wiring to
suit
> whatever HA bits I want to add will be nice&  easy...
>
> Paul G.
>
>
> -----Original Message-----
> From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of
> craig
> Sent: 29 October 2010 08:38
> To: ukha_d@xxxxxxx
> Subject: RE: Fw: [ukha_d] How would YOU approach this HA task?
>
>> connections outside the boiler simply because only a
Corgi/Gas-Safe
>> registered engineer is supposed to open the boiler. Of course
Part-P
>> probably applies to the wiring too :(
> Another approach would be to use a room stat that has infra red
capability,
> eg heatmiser:
>
>
<http://www.heatmisershop.co.uk/products/Programmable-Thermostat-%252d-Heatm
> iser-PRT.html>
>
>
> and use infra red to control the heating from Comfort (or similar).
You
> would also be able to control the temp, rather than just on off.
>
> This wouldn't require any complications with 'non-standard' wiring to
the
> bolier, and totally isolated from any CH electrical circuits.
>
>
>
>
>
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