CPC used as interconnect on smoke detectors

[Pete999]

Interesting one here.

My initial reaction is a C2. Then when you think about it it is 8-12 volts DC that only has a single layer of insulation.

Would I C2 a speaker cable in the wall? No of course not.

If everything is also Class 2 then again I fail to see how to code this.

The cpc in question, does not have any insulation, the sleeving if used will only be an indicator.

 

[davesparks]

Interesting one here.

My initial reaction is a C2. Then when you think about it it is 8-12 volts DC that only has a single layer of insulation.

Would I C2 a speaker cable in the wall? No of course not.

If everything is also Class 2 then again I fail to see how to code this.

Is it definitely 8-12V DC on the interconnect? And is that SELV or otherwise fully isolated from LV with no possibility of a fault making it live at 230V?
I have a feeling that manufacturers say the interconnect should use wiring to the same standard as the supply.

 

[bigspark17]

C2. No question!!

 

[Pete999]

Is it definitely 8-12V DC on the interconnect? And is that SELV or otherwise fully isolated from LV with no possibility of a fault making it live at 230V?
I have a feeling that manufacturers say the interconnect should use wiring to the same standard as the supply.

An obviously correct answer Dave, quite what the problem is I'm not sure, does make you wonder though.

 

[Adam W]

If the interconnect is ELV then the CPC isn't segregated or insulated to the highest voltage band, so C3.
I suppose you could say if the interconnect were 230v there is insufficient insulation since the outer sheath is intended for mechanical protection only, so C2?

 

[Octopus]

Reg 411.8.5 BYB maybe?

 

[bigspark17]

The interconection cable is 240v isnt it?? :/

 

[Adam W]

The interconection cable is 240v isnt it?? :/

Not on Aico gear. There may be others as well.

 

[bigspark17]

Find that hard to belive.. testers will be on it tomorrow!!

 

[polo1]

as a non-electrician, I have a question...
if the cable used to interconnect is at mains voltage, shouldn't it have a cpc, even if the individual detectors don't need one?

If the detectors were non mains supplied, then any 3 core cable would do the job, but T&E presence might cause unnecessary confusion to someone opening up at a later date?

Radio interconnect is an option (a good one, imho) but not an option in rented housing...but in Scotland it will be soon, thankfully.

Hope i have explained that correctly...

Where have you taken the above info from? Do you understand that 10 yr battery, radio linked will meet the revised Regs (ie not hard wired & radio linked)?

 

[Octopus]

Where have you taken the above info from? Do you understand that 10 yr battery, radio linked will meet the revised Regs (ie not hard wired & radio linked)?

Are you 100% sure about the 10 year battery bit?

 

[pirate]

Yes, I do understand that Polo1...but although the scottish government have agreed that 10 year battery , radio interlinked will be allowed (and rightly so) it is not law yet. I have installed stuff where the first detector is mains and 10 year battery back-up, with radio interlink, the others are 10 year battery only, with radio interlink. In a small flat it makes sense as you can hear any one of them from anywhere in the flat. My question was whether there might be confusion if some T+E were present...in wired, interlinked installations.
I presume you meant ie not hard wired and radio linked only, and not mains powered at any point. That is certainly the outcome of the consultation, imho.

 

[pirate]

Yes, I do understand that Polo1...but although the scottish government have agreed that 10 year battery , radio interlinked will be allowed (and rightly so) it is not law yet. I have installed stuff where the first detector is mains and 10 year battery back-up, with radio interlink, the others are 10 year battery only, with radio interlink. In a small flat it makes sense as you can hear any one of them from anywhere in the flat. My question was whether there might be confusion if some T+E were present...in wired, interlinked installations.
I presume you meant ie not hard wired and radio linked only, and not mains powered at any point. That is certainly the outcome of the consultation, imho.

 

[pirate]

Murdoch, yes...the whole point about the consultation, on this matter anyway, was whether modern tech has brought us to a place where 10 year Lithium battery powered detectors can be used and relied upon. I have the government response on file somewhere, and will try to find it and send you a link. In essence, in Scotland you will be able to use 10 year battery modules, radio interlinked. It's a good step, because landlords will see it is cheaper than the old regs, so will be more likely to comply.

 

[polo1]

Are you 100% sure about the 10 year battery bit?

No I’m not M, that’s why I posed the question.
The Scottish Gov recently announced that the standards which currently apply in new build and private rented (mains supplied and interlinked smokes in the main living area, hall and heat in kitchen) are to be applied to existing owned and public sector/HA property. The announcement made reference to detectors being no more than 10 yrs old but otherwise was light on detail about the spec and how the change is to be implemented.
Their review was prompted by the Grenfell Tower fire.

 

[Wilko]

Hi - I understand that BS5839 already permits radio linking of mains powered alarms. There are a few conditions and reading the instructions from Aico on their Ei100MRF radio units, they meet those requirements when properly installed and commissioned.

 

[polo1]

Pirate,
Can you tell me exactly where you have read that 10yr battery only radio interlinked detectors will be acceptable when the Scottish legislation is changed?
Tia

 

[pirate]

Polo1, have a look here:
https://scottishlandlords.com/news-and-campaigns/news/parity-safety-standards-announced/
and the links within

Hope this helps

 

[polo1]

“The following changes to this standard, all supported by the responses to the consultation, are also proposed:

• to allow specified types of sealed long-life battery alarms as well as mains-wired alarms - reflecting the availability of appropriate technology and will encourage compliance;
• to specify a maximum age of ten years for alarms; and
• to require carbon monoxide detectors in all homes.”

The above taken from the Scottish Gov web site. Have to say I’m really surprised on the battery only detectors. It also says “proposed”, so I wonder if it will make the final cut.

 

[pirate]

I am sure it will make the cut!
Hope so, frankly...