CPC used as interconnect on smoke detectors

[sparkdog]

Don't think its really a potential danger per-above post.

 

[Lucien Nunes]

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.

But 12V with respect to what? A live conductor. If you connect one side of a PP3 to mains, the PP3 is still 9V but now it's potentially lethal (pun intended).

 

[Wilko]

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...

Yes all cable installed shall have suitable cpc travelling with it. I'm not aware of battery alarms that ask for wire interconnect, so not thought about that one. It does annoy me that some folks steal it for some other purpose. Radio clearly the way forward for difficult situations .

 

[Pete999]

The cpc in this case, has a distinct possibilty of making contact with one of the Live conductors in the detector and or the cable itself, if the cable become damaged, the cable is not being used as it should, so it should be replaced with a cable that is fit for purpose.
It's an inherently dangerous thing to do in my bok, would you use the cpc in respect of the strappers in a 2 way lighting circuit, well I know I wouldn't with that in mind you should code it as dangerous.

 

[Risteard]

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

The cpc core is uninsulated.

 

[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)?