Smoke Alarm - cable colours

5 Jun 2006
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United Kingdom
Can I have some clarification on which colour cores to use when wiring in my mains smoke alarms? They have an interconnect wire (white).

The manual states:
Line - Red or Brown
Neutral - Black or Blue
Interconnect - Black

Now, I don't have two black cores in my 3+E cable, which one should be using the grey?

Should I use:
Live - Brown
Neutral - Black
Interconnect - Grey

I am not quite comfortable with this as Brown is a new cable colour and Black is the old neutral, I feel this is confusing two versions of the colour system.

This leaves:
Live - Brown
Neutral - Grey
Interconnect - Black

This feels better to me, but is using grey for neutral OK?

PS LABC notified.
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either is fine by BS7671 but grey as neutral is the convention the electromafia preffer. make sure you sleeve the neutral blue.
Only necessary to sleeve if it is carrying mains voltage - I rather think the interconnect will be a low voltage telemetary signal. I stand ready to be corrected by alarming people :)

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I dont know the exact voltage, but the Interconnect is not mains voltage.

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