Smoke Alarm Link Cable

[sparkyspike]

Can anybody resolve an argument for me? I was told by a Kidde engineer that the link cable between 230v smoke alarms is only ELV. Firstly is this true? If it is, then surely 3-core cable should not be used between alarms?

 

[Spark123]

The signal wire between the alarms will be ELV, (poss FELV?) however it is designed that way so that if the mains fails the interconnections will remain under battery power.
As far as the regs are concerned they are installed to the manufacturers instruction.

 

[Lectrician]

ELV and mains can be run together as long as the ELV cable is mains rated.

When unterlinking, it is the norm to use the brown as live, grey as neutral and the black as interlink. Sleeve the grey blue but DO NOT sleeve the black. Black is already coloured for an ELV cable. Do not sleeve it brown!

 

[sparkyspike]

Hi Lectrician. Don't worry, I don't sleeve the black as this would indicate a phase conductor. I have checked this before, and I think the wording of 528.1 is ambiguous. It implies that you cannot run a Band I with Band II. But it depends how you read it.

Anyway, if the unit is designed for this method of installation then fine, that answers my question.

SS