Interlink smokes wired in 3core flex

[p11jor]

As title, just clocked this on a job I am on, all conductors correctly sleaved,

Has anyone saw this before?

I have always used 3core&e

 

[cobrauk]

All 230volt circuits require a cpc, even if it isn't connected to a piece of equipment that needs earthing, so my answer is no its not wired correctly and anyway a flex shouldn't be used as fixed wiring in my opinion.

 

[tom79bmth]

When I see things like that I always wonder what else they done on the job

 

[p11jor]

When I see things like that I always wonder what else they done on the job

Me too I am doing a a board change so gots to test the place after lunch!

 

[glasgospark]

would a circuit that is soley dedicated to smoke alarms require connected earths at each point even though they wouldnt be connected

 

[Q.S.]

would a circuit that is soley dedicated to smoke alarms require connected earths at each point even though they wouldnt be connected

Yes - all points must be earthed and these connected back to the consumer unit or D.B., even it the point has a class fitting on it.

 

[Stroppy]

Whether the load (alarm/light/socket) needs an earth or not is irrelevant. As has been stated the cable itself needs an earth to help detect faults if it is damaged. I believe this is why in T&E the cpc is not sleeved: so that a damaged line or neutral has more chance of touching it and tripping the protective device. Otherwise it would need the insulation of the line AND earth to be damaged to make a connection to the CIRCUIT protective conductor.

 

[p11jor]

I have actually just had to purchase 100metres of 3core & earth 1mm for a little commercial job. £42 incl vat......so I think it goes down to lazyness oppose to cost, as I am sure flex is a bit more expensive than that......correct me if I am wrong

 

[High Tower]

Nah flex is about half that, no excuse in my book

 

[kingeri]

All 230volt circuits require a cpc, even if it isn't connected to a piece of equipment that needs earthing, so my answer is no its not wired correctly and anyway a flex shouldn't be used as fixed wiring in my opinion.

Absolutely nothing wrong with it when used appropriately. Not saying this is appropriate though!

 

[High Tower]

I use a fair bit of flex on mains wiring, it's double insulated and rated for 230, so in the right situation I really don't see why not. However using 3 core on interlinked smokes is a big no!!

 

[MDJ]

I wish I could find the thread discussing earths in circuits we discussed a few months back lol, I had a look via the search but as of yet I can't find it for looking, there were some good arguments regarding class 2 circuits and no earths, I think I got a hiding from memory sugesting CPCs were essential in the cable even if they were not connected, some members here turned me over and others about this haha, you may well change your mind about cpcs in cables for class 2 equipment if you read it LMAO.

 

[kingeri]

Main argument for me is that in the future the Class 2 device might be replaced with something needing an earth. And of course, the presence of a CPC in a cable does make it more likely that the protective device will operate if the cable is damaged.

 

[MDJ]

thing is though when you design a circuit you don't need to think about what may or not may happen in the future, so that argument won't hold, however IMO every 230 volt circuit should contain a CPC, end of, but as mentioned there was some good arguments about this last time we went down this route, even though I was right haha

 

[Darkwood]

How about replacing all smokes with mains powered radio linked units instead and re-establishing the earth core... cheaper and rewiring the lot i would assume.....