Interconnected mains smoke alarm wiring

[Hartly]

Hi, I am wiring a series of mains interconnected smoke alarms using 3 -core and earth cable. The alarms do not have an earth terminal.

This wiring plan was suggested as it would avoid using the earth for the interconnection wire, and therefore potentially confusing anyone else examining the wiring.

Am intending to connect the black to the line (with a brown sleeve), brown to neutral, and grey to the interconnect, but what to do with the (unused) earth wire?

I could connect it up along the smoke alarm junction boxes, but I think this would be dangerous, as although it would be connected at one end to the consumer unit, nothing else would be connected to it. I could trim it back to the flex which might be better. I understand you can get special interconnect wire, but it is probably better in the protective sleeve that comes with conventional cable.

Any ideas please?

Thanks.

 

[Belle427]

sleeve it and place in a connector,weither it be in a jb or choc block

 

[Spark123]

I'd use brown as the live, grey sleeved blue as neutral and black sleeved brown as the interlink.

 

[ShropshireLad]

Ditto from me

Brown as the live,
Grey with Blue sleeve as Neutral and
Black sleeved brown as the interlink.

Earth with sleeve on into a connector.

 

[Taylortwocities]

Ditto on the colours.
The earth conductor must be connected to the circuit's earth at beginning and be connected through each alarm location so there is still an earth at the last fitting.

This conductor is properly called the circuit protective conductor (cpc)
its there for a purpose.
Iys there to provide an earth fault path if the cable is damaged. You'll also need it to determine the value of Zs for the circuit.

 

[Sparks1873]

I personally have always used flat 3 core with no cpc. Brown live, Black neutral, grey as the interconnector. No sleeving!

 

[riveralt]

I personally have always used flat 3 core with no cpc. Brown live, Black neutral, grey as the interconnector. No sleeving!

And no testing then either

 

[Taylortwocities]

I personally have always used flat 3 core with no cpc. Brown live, Black neutral, grey as the interconnector. No sleeving!

McCowboy

 

[Alarm]

I hate people who dont earth or cut off.

Just worked on a fire system ( FP100) and all earthing cut out. Fitted by a national company.
Quoted to rewire.

 

[ban-all-sheds]

This wiring plan was suggested as it would avoid using the earth for the interconnection wire, and therefore potentially confusing anyone else examining the wiring.

You didn't realise that this was much more than a nicety to avoid confusion?

That it was absolutely essential to not use the cpc to avoid a serious contravention of the wiring regulations?

Before you even contemplated installing these alarms you should have known not to use the cpc as an interconnect, and should not have needed it to be suggested to you and should not have viewed not using it as only a good idea to avoid confusion.

Am intending to connect the black to the line (with a brown sleeve), brown to neutral, and grey to the interconnect,

Who on earth came up with that scheme, and why?

I could connect it up along the smoke alarm junction boxes, but I think this would be dangerous, as although it would be connected at one end to the consumer unit, nothing else would be connected to it.

You have worryingly weak grasp of things.

I could trim it back to the flex which might be better.

FFS.

Any ideas please?

Yes - please get to the stage of knowing what you are doing BEFORE you dive in and actually do, particularly for safety services.

 

[holmslaw]

..

 

[Paul_C]

I personally have always used flat 3 core with no cpc. Brown live, Black neutral, grey as the interconnector. No sleeving!

Where can one buy 3-core without earth in the new colors then?

 

[ban-all-sheds]

Shouting at the moon again, Hartly's post is over 4 years old.

Oh b****cks.

 

[JohnW2]

Shouting at the moon again, Hartly's post is over 4 years old.

Oh b****cks.

Don't fret. It actually enhances our view of you as a human being to see you making the same mistake for which you frequently take others to task

Kind Regards, John.

 

[EFLImpudence]

Where can one buy 3-core without earth in the new colors then?

Fife.