Knew this would be a pita - but decided to go for it .

Wiring has been in for years 🙄😊

Anyway 1 wire link from the previous sensor seems dead . This cable is just mains - radio used to trigger neighbors off ( tested works fine ) . It’s I think close to impossible to thread a new cable through . Dead cable it appears to be ‘stuck’ and inaccessible.

What are the rules on powering fire alarms ? . Can it be simply off a socket ( I have some in the loft that *might* make it easier ) .

Or do they all have to be linked off the same mains cable supply ???

Right pita !

Edited September 30, 20242 yr by Pocster

I found this

 

https://www.tlc-direct.co.uk/Technical/Regulations/Fire1.htm

• 1.17 The power supply for a smoke alarm system should be derived from the dwelling’s mains electricity supply................If alarm comprises no stand by power supply, [ie AC ONLY] no other electrical equipment should be connected to this circuit. [ie AC only alarms, must only be wired back to main consumer unit on dedicated circuit].
• 1.18 A smoke alarm, or smoke alarm system, that includes a standby power supply or supplies, [ie AC with battery back up], can operate during mains failure. It can therefore be connected to a regularly-used local lighting circuit. ...............

 

Suggesting that as they are battery backup they can be mains powered off pretty much anything....?

At our last place we wired out heat and smoke alarms, which had battery backup, off the lighting circuits. It was all signed off ok.

1 minute ago, Gone West said:

At our last place we wired out heat and smoke alarms, which had battery backup, off the lighting circuits. It was all signed off ok.

 

That seems fairly standard.  I think the reasoning is that you will notice the lights not working in the event that the circuit fails and the battery backup will mean the alarms still function.

Perfect ! I’ll just hack it away . My concern was when sparky does sign off he will see fire circuit on CU . He might turn that off to check the batteries on the units . But of course some of the alarms won’t be wired directly off the CU . Don’t want him to have an issue …

Aico do 10 year life battery alarms that will interlink wirelessly to their mains alarms and building control here accept the,

12 minutes ago, ProDave said:

Aico do 10 year life battery alarms that will interlink wirelessly to their mains alarms and building control here accept the,

Yeah I’ve got 10yr battery wireless mains powered ( safelinc I think - much cheaper ) . It was how they are mains powered was my issue . But I’ll just do as others have done .

Edited September 30, 20242 yr by Pocster