Connecting 3 new smoke alarms in 3 storey house

[HarryUK]

Hi

I'm trying to replace 3 smoke alarms in a 3 storey building. The smoke alarm units each have a brown, white and blue set of wires.

On the top floor the existing alarm was connected to a red, yellow and blue wires in the ceiling.

On the second floor I have the red, yellow and blue wire, but this time there are two of each colour going into the connector.

On the group floor I have a single blue, black and yellow wire, but also have two red wires. The two red wires werent connected to the existing alarm.

Can somebody provide guidance on how to wire up the 3 new alarm units the instructions arent that helpful and I seem to have a different set of wires on each floor!

 

[Alarm]

Sounds like interconnecting ones to me.
Time to isolate and test with a meter.

On the alarms the brown was live/line
blue was neutral
white was the switch/interconnect.
They are interconnected and run from the lighting circuit from the sound of it.
You have to identify the interlinks and the lighting circuits separately with the mains isolated of course.

As you able to do the above safely? And test the units after?

 

[HarryUK]

Hi

Thanks all sorted and interconnected!

 

[sparkwright]

Sounds like interconnecting ones to me.
Time to isolate and test with a meter.

On the alarms the brown was live/line
blue was neutral
white was the switch/interconnect.
They are interconnected and run from the lighting circuit from the sound of it.
You have to identify the interlinks and the lighting circuits separately with the mains isolated of course.

As you able to do the above safely? And test the units after?

How can you tell whether it's connected to the lighting circuit or not from the description?

To the op, I realise you have completed the work, but to confirm, all the yellows should be interconnect link wires, all the reds should be L, and all blues and blacks should be N.

 

[Alarm]

I said "From the sound of it".
As this type generally is.

Also mentioned to isolate and test.

Did I miss something?

Oh yeah test all afterwards too.

 

[sparkwright]

I said "From the sound of it".
As this type generally is.

Also mentioned to isolate and test.

Did I miss something?

Oh yeah test all afterwards too.

Ok.

How from the sound of it how can you tell it may be connected to the lighting circuit?

( )

 

[Alarm]

new game is it?

Generally interlinked smokes are a second though and Aico is a popular make. Whom say to fit to the lighting circuits.
Although we can see a 3 core and cpc has been run it is still possible they are connected to the lighting circuit.

Also the colour change at the bottom, although this could be because of a latter modification and the new colours used.

( Do not like the lighting circuits used personally but there you go, but it isnt a true fire system is it).

Any better for you ?

 

[sparkwright]

Honestly, I'm not having a go.

The colour change at the bottom is simply where the feed is a twin and earth consisting of one red and one black; and the 3 core and earth cable going to the second alarm consisting of one red, one yellow, one blue.

The feed cable would usually come from a lighting circuit, or it's own circuit.

Personally I like to run the cable back to the consumer unit where either option can be adopted.

It's ok, I'm not trying to wind you up.

 

[JohnW2]

The colour change at the bottom is simply where the feed is a twin and earth consisting of one red and one black; and the 3 core and earth cable going to the second alarm consisting of one red, one yellow, one blue.

That's what I assumed, but there's something less than straightforward with what we're being told. If the above assumption is correct, then the original alarms were not getting mains power at all (neither red was connected), although the (assumed) supply neutral was (by implication) connected to them.

Kind Regards, John.

 

[Alarm]

Honestly, I'm not having a go.

The colour change at the bottom is simply where the feed is a twin and earth consisting of one red and one black; and the 3 core and earth cable going to the second alarm consisting of one red, one yellow, one blue.

The feed cable would usually come from a lighting circuit, or it's own circuit.

Personally I like to run the cable back to the consumer unit where either option can be adopted.

It's ok, I'm not trying to wind you up.

I know, I just said all that
I would rather not use them but it is acceptable in a domestic, not in other places IMHO.
As you say a clean supply is my also preferred.
No wind up taken, just thought you needed some education

And I dont think it was connected either when the question was asked.

 

[sparkwright]

I read it as at the bottom alarm the two reds could have been connected together, but not connected to that particular alarm.

 

[Alarm]

Agreed, thus making the interlinks inoperative with that first device also.

 

[JohnW2]

I read it as at the bottom alarm the two reds could have been connected together, but not connected to that particular alarm.

As I said, it wasn't clear - but if what you say were right, wouldn't that have left the bottom alarm without an L power feed?

Kind Regards, John.

 

[sparkwright]

It would yes. Perhaps some attempt to disconnect that one alarm. Or even a wire broken off.

Since the op's description wasn't very clear it's hard to say for sure what's been going on.