Smoke Detectors with Idratek

[KirasHome]

Hi there,

I'm thinking of replacing some of the smoke detectors in the house. I'd like to get some I can hook into Cortex via the digtial inputs. Has any tried this? And does anyone have any recommendations?

Thanks, Jamie

[Gumby]

Kidde do an interlinkable mains range of alarms and they have an optional "relay base" that can give a contact closure when active. Or perhaps it's NC - can't remember offhand.

[n07tv]

You would defintely need the isolation as all the interlinked mains smoke alarms I have seen are all floating at maisn potential. I never did work out if the 'trigger' wire came live on detection or went to neutral.

As Gumby says, a relay based one would be ideal. Always thought it would be a good idea to automatically turn on lights in the unfortunate event of a fire.

N.

[Karam]

Might this 12V one be suitable? :

http://www.tlc-direct.co.uk:80/Products/TLSD12.html

Neither tried this nor is it a particular recommendation, just remember seeing it in response to a similar query some time ago. Also note that it appears to have a maximum voltage rating of 14V so you may need a diode drop or two if you use with an IDANet running at its maximal 15V supply rating.

[KirasHome]

Thanks guys,

I had a look at the Kiddie relay base and that looks pretty good. It's got both NO and NC connections on an 8A 24V DC / 8A 250V AC rated relay. It appears that the relay is driven from the interconnect link and it also says that you can connect up to "23 Mains powered Kidde Fyrnetics
Smoke, Heat or CO interconnectable alarms" to the relay. So it appears any alarm going off would trigger the relay.

There is a version with a smart interconnect that allows Fire and CO alarms to be linked, but I suspect integrating that would be a bit more complex.

Jamie

[JonS]

I looked at mains based detectors including the Kidde one mentioned. I sent the spec sheet for the relay base to karam who considered the isolation between the mains and relay outputs to be weak. In the end I chose 9V interlinked units with 10yr batteries. Completely independent of mains, from a reliability and frying Idranet PoV, internal sounders (which some of the alaram panel ones do not have) and interlinkable with others, range of ionisation, heat and optical. IIRC these are from Ei via safelincs.
However I have yet to interlink them with DIs (all cables (alarm cable) home run to N-zero). The plan is to use a "simple optical isolator" (the link signal is 9V), but just haven't had time to do it yet, not had time for any enhancements lately, but Idranet just works pretty well without intervention :-)
HTH
JonS

[Karam]

Ah yes, if memory serves me I think it did not provide for segregation of digital (ELV) wiring and mains (LV) wiring so needed some sort of barrier to be fashioned, or both sets of wiring to be securely tethered in some way? Depending on other physical aspects you might be safe enough if you use mains rated cable for digital inputs. From a common sense point of view you have to consider if there is a possibility (and you should think of some feasible faults such as cables working/breaking loose from terminals) for ELV to come into contact with LV. Contact also means contact through an insufficiently rated isolation barrier eg. < mains voltage rated sleeving. Well IMHO anyway ...

[KirasHome]

In the end I chose 9V interlinked units with 10yr batteries. Completely independent of mains, from a reliability and frying Idranet PoV, internal sounders (which some of the alaram panel ones do not have) and interlinkable with others, range of ionisation, heat and optical. IIRC these are from Ei via safelincs.

Thanks JonS, looks interesting. Any ideas how the signalling? Does it just take a signalline from 0v to 9v ? Is there any modulation? As you say an opto-isolator would be a sensible precaution.

Idranet just works pretty well without intervention :-)

That's very true :-)

Karam - do you have any opto-isolators you particularly recommend for protecting the DIs ?

Thanks, Jamie

[Karam]

Karam - do you have any opto-isolators you particularly recommend for protecting the DIs ?

I suppose there are quite a few out there. We use fairly common TLP621s elsewhere (5000V isolation, 6.4mm creapage). There are also multiple unit/package variants. If you're thinking of using these to circumvent the segregation issue then you're also going to need some sort of independent supply to drive the Optoisolator LED.

[marcuslee]

Thanks JonS, looks interesting. Any ideas how the signalling? Does it just take a signalline from 0v to 9v ? Is there any modulation? As you say an opto-isolator would be a sensible precaution.



That's very true :-)

Karam - do you have any opto-isolators you particularly recommend for protecting the DIs ?

Thanks, Jamie

Hi All,

Old thread, but anyone know if this was the final definitive on a good option for smoke alarms + Idratek?

Cheers,

Marcus