RE: Re: Smoke alarms

["JonShaw" <semi.jon@xxxxxxxxxxxxx>]

Following up this after a pause I have decided to go for the Kidde
mains
voltage system mentioned below.  I decided that the fire alarm  is so
important that it needs to be totally independent of any HA and what every
maintenance I am doing on it.  I wrote to Kidde and got this answer:

1. All Kidde alarms are interconnected together using a 3core & earth
type
cable. The black coloured core is used as the I/O wire and this carries the
signal to all other alarms on the circuit. The signal is ELV DC and this
then will activate all of the alarms at the same time. Other alarm
manufacturers use a different voltage and this is why you can not mix
manufacturers alarms in one installation.



2. The SMK 23R relay base will only trigger if the smoke/heat alarms are
activating. The relay will not trigger with any interconnected hard wired
Kidde CO alarms.



3. The SMK 23R relay offers the user a way of activating a third party
device through a set of volt free contacts. The relay is connected into the
smoke alarm circuit as if you were wiring in another smoke alarm. The unit
has three sets of block connectors which you would connect in the alarm
cables and a set for the third party device which you would wire in your
third party device. The third party device switch has three terminals,
common, N/O and N/C . The switch is volt free which means that the third
party device could be any LV supply. Please note that the alarm circuit
does
not provide any voltage that can be used to trigger any third party
devices.



4. The relay will not activate if mains voltage is lost.



I ran this past Idratek and the main issue is likely to be physically
separating mains and the connection to an Idranet Digital input, so that if
a cable works loose there is no chance of cables and contacts mixing.



I am disappointed that CO doesn't trigger the relay, but it becomes a
project for the future!



HTH

Jon (catching up on some correspondence!)

PS do people use normal grey flat mains cable for smoke alarms or a
different cable to distinguish it?  I guess a label every meter would do??



_____


Subject: Re: Smoke alarms





Thanks Pauls

OK.  Idranet is basically 15V with a 12V back-up battery (presume 15V PSU
to
allow enough volts to charge the battery)



Is Comfort similar and if so, what detectors do you use?



I feel a call to Kidde coming on, their Fyrnetics range includes
ionisation,
optical, heat and CO sensors all interlinkable in both mains and battery
versions, though I suspect battery =9V :-(



Do you use 9V detectors and step the voltage down somehow?



Jon




<http://groups.yahoo.com/group/ukha_d/message/139722;_ylc=X3oDMTJzbTlsdjQ2BF
9TAzk3MzU5NzE1BGdycElkAzExMDk2MzkEZ3Jwc3BJZAMxNzA1MDQxOTkyBG1zZ0lkAzEzOTcyMg
RzZWMDZG1zZwRzbGsDdm1zZwRzdGltZQMxMTY4NTEyODMx> Re: Smoke alarms

Posted by: "Paul Gale"
<mailto:groups@xxxxxxx?Subject=%20Re%3A%20Smoke%20alarms>
groups@xxxxxxx    <http://profiles.yahoo.com/psghome2002>
psghome2002

Thu Jan 11, 2007 12:57 am (PST)

You don't use mains voltage smoke sensors - use 12V types and these connect
directly to one of Comfort's zone inputs.

Paul.





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