The mains powered smoke detectors in my house need replacing.

At some future time I'm considering using Z-wave for some heating controls.
Having mains powered Z-wave nodes to help with mesh connectivity seems
like a good idea, and having alarms where one sensor can set off all
the alarms also seems sensible (but not so worthwhile I'm keen to pull new
signal wires through).

http://www.fibaro.com/en/system-fibaro/smoke-sensor-en
"You can connect the sensor to 12 or 24 VDC adapter if you wish" is going
to look a mess, or involve making a large enough hole to tuck a socket and
adapter inside the ceiling where now there is just a hole for a cable.

Mains powered alarms with radio interconnects that don't specify a standard
and are presumably manufacturer specific are easy to find (and would be
easier to set up the networking).

Other battery powered Z-Wave connected alarms exist.
http://getvera.com/z-wave-smoke-detectors-brainers/
http://www.uk-automation.co.uk/produ...-Detector.html
http://www.everspring.com/SF812.aspx

But not, as far as I can find, the combination. Am I missing something?

And if I did switch to battery-only powered alarms, what's the best way
to safely and neatly terminate the existing cable without enlarging holes
more than necessary, and without sticking junctions boxes on the ceiling?

On 27/01/15 13:24, Alan Braggins wrote:
The mains powered smoke detectors in my house need replacing.

At some future time I'm considering using Z-wave for some heating controls.
Having mains powered Z-wave nodes to help with mesh connectivity seems
like a good idea, and having alarms where one sensor can set off all
the alarms also seems sensible (but not so worthwhile I'm keen to pull new
signal wires through).

http://www.fibaro.com/en/system-fibaro/smoke-sensor-en
"You can connect the sensor to 12 or 24 VDC adapter if you wish" is going
to look a mess, or involve making a large enough hole to tuck a socket and
adapter inside the ceiling where now there is just a hole for a cable.

Mains powered alarms with radio interconnects that don't specify a standard
and are presumably manufacturer specific are easy to find (and would be
easier to set up the networking).

Other battery powered Z-Wave connected alarms exist.
http://getvera.com/z-wave-smoke-detectors-brainers/
http://www.uk-automation.co.uk/produ...-Detector.html
http://www.everspring.com/SF812.aspx

But not, as far as I can find, the combination. Am I missing something?

And if I did switch to battery-only powered alarms, what's the best way
to safely and neatly terminate the existing cable without enlarging holes
more than necessary, and without sticking junctions boxes on the ceiling?


Not ZWave but NEST do RF - smartphone connected smoke alarms.

In article , Tim Watts wrote:
On 27/01/15 13:24, Alan Braggins wrote:
The mains powered smoke detectors in my house need replacing.

At some future time I'm considering using Z-wave for some heating controls.
Having mains powered Z-wave nodes to help with mesh connectivity seems
like a good idea, and having alarms where one sensor can set off all
the alarms also seems sensible (but not so worthwhile I'm keen to pull new
signal wires through).
[...]
Mains powered alarms with radio interconnects that don't specify a standard
^mostly
and are presumably manufacturer specific are easy to find (and would be
easier to set up the networking).
[...]
Not ZWave but NEST do RF - smartphone connected smoke alarms.

True - I had counted it as manufacturer specific networking, but _possibly_
it would take part in a ZigBee mesh. And it's less than twice as expensive
as the Fibaro, and nicer in some ways.

On 27/01/15 13:24, Alan Braggins wrote:
The mains powered smoke detectors in my house need replacing.

At some future time I'm considering using Z-wave for some heating controls.
Having mains powered Z-wave nodes to help with mesh connectivity seems
like a good idea, and having alarms where one sensor can set off all
the alarms also seems sensible (but not so worthwhile I'm keen to pull new
signal wires through).

http://www.fibaro.com/en/system-fibaro/smoke-sensor-en
"You can connect the sensor to 12 or 24 VDC adapter if you wish" is going
to look a mess, or involve making a large enough hole to tuck a socket and
adapter inside the ceiling where now there is just a hole for a cable.

You could use a 12V SELV lighting PSU, either remotely if you can get
the cable to it, or cut a downlighter sized hole in the ceiling and push
it up and through, covering the hole with the alarm?

In article , Tim Watts wrote:
On 27/01/15 13:24, Alan Braggins wrote:
The mains powered smoke detectors in my house need replacing.

At some future time I'm considering using Z-wave for some heating controls.
Having mains powered Z-wave nodes to help with mesh connectivity seems
like a good idea, and having alarms where one sensor can set off all
the alarms also seems sensible (but not so worthwhile I'm keen to pull new
signal wires through).

http://www.fibaro.com/en/system-fibaro/smoke-sensor-en
"You can connect the sensor to 12 or 24 VDC adapter if you wish" is going
to look a mess, or involve making a large enough hole to tuck a socket and
adapter inside the ceiling where now there is just a hole for a cable.

You could use a 12V SELV lighting PSU, either remotely if you can get
the cable to it, or cut a downlighter sized hole in the ceiling and push
it up and through, covering the hole with the alarm?

Good idea. I'm so used to "mains to DC adaptor" meaning "wall-wart", I didn't
think of that. And
http://www.fibaro.com/manuals/en/FGF...en-2.1-2.3.pdf
says "In DC powering mode, configuration and association parameters are sent
when necessary, and additionally the smoke sensor serves as a Z-Wave signal
repeater." However it also says "It's not possible to power the device from a
battery and VDC power source simultaneously. When using a VDC power source it's
recommended to use another kind of power back up" which complicates things.

On 30/01/15 15:35, Alan Braggins wrote:

Good idea. I'm so used to "mains to DC adaptor" meaning "wall-wart", I didn't
think of that. And
http://www.fibaro.com/manuals/en/FGF...en-2.1-2.3.pdf
says "In DC powering mode, configuration and association parameters are sent
when necessary, and additionally the smoke sensor serves as a Z-Wave signal
repeater." However it also says "It's not possible to power the device from a
battery and VDC power source simultaneously. When using a VDC power source it's
recommended to use another kind of power back up" which complicates things.


One thing I just thought of: double check the 12V SELV pack offers clean
smoothed DC.

I might have been talking ******** as I checked and most don't specify
DC output and some, even the electronic ones claim to be AC output.

The other thing to watch for is minimum loads as this alarm is going to
present negligible loading - there are some SELV PSUs that expect
minimum loads. Others don't care. Should be in the spec.

I would suggest bending your search towards 12V LED drivers - more
likely to find a DC output.

eg maybe this:

http://www.screwfix.com/p/a/85503

It is 12v DC adn designed for lobbing into a ceiling void - it is not
clear how clean the output is