EICR today Mains smoke detectors interlinked

[Stevie g]

Good evening all
3 buildings :
1 Gf flat and 1St fl flat year 1915
2nd 6 flats year 1980
3rd cottage year 1900
They are separate buildings probabley 2in between them, 1 landlord owns all,
I ve done EICR on 1st building and 1 flat in 2nd building and found that the mains smoke detectors are interlinked hard wired between buildings no local isolation in buildings and not come across the power source that supplies them.
? What code
? Am I going mad is this allowed

 

[Welchyboy1]

are the smokes from this circuit sited inside all the flats too?

 

[Farmelectrics]

know code at all the smoke alarms are not part of the fixed wire testing. nothing wrong with making recommendations however you don't need to

 

[Ziggie]

Good evening all
3 buildings :
1 Gf flat and 1St fl flat year 1915
2nd 6 flats year 1980
3rd cottage year 1900
They are separate buildings probabley 2in between them, 1 landlord owns all,
I ve done EICR on 1st building and 1 flat in 2nd building and found that the mains smoke detectors are interlinked hard wired between buildings no local isolation in buildings and not come across the power source that supplies them.
? What code
? Am I going mad is this allowed

Most interesting question.
From a safety point of view, if all detectors have battery backup and all are tested, then other than evacuating buildings unnecessarily, it must be safe as everyone is warned.

the danger of false alarms over tcausing people to ignore the real one may be a risk.

The interlinking is presumably an output rather than the mains powering, and so would be considered a data signal rather than mains electricity.

this would mean that this would be similar to a factory fire system where the factory has several buildings. Systems quite commonly had 2 levels - your building is on fire and your building is not on fire but somewhere else locally is.

So I personally don’t think it is a problem.

Having worked in an explosive factory for many years, we preferred to know if any building was on fire.

 

[littlespark]

Are you sure they are interlinked by wires, and not radio? (Such as aico?)
They might just be picking up the neighbours detectors

 

[Ziggie]

The aico system uses unique encoding system to prevent detectors firing (pairing system) but obviously other systems might not.

they may be 10 year lithium battery units.

these are recommended in Scotland by law as well as mains powered.

 

[loz2754]

If the smoke alarms are powered from a different supply to the building they are in, then there should at least be warning notices that there is more than one source of supply.
Though I don't see the purpose or reasoning behind having smoke alarms interlinked between separate buildings.
Further investigation would be beneficial.

 

[loz2754]

know code at all the smoke alarms are not part of the fixed wire testing. nothing wrong with making recommendations however you don't need to

Not true. The mains supply to the alarms is covered by fixed wire testing.

 

[Lister1987]

The aico system uses unique encoding system to prevent detectors firing (pairing system) but obviously other systems might not.

they may be 10 year lithium battery units.

these are recommended in Scotland by law as well as mains powered.

Did the aico expert install training today, was good.

Thing to note about radiolink, they will retain the factory setting unless changed, meaning if Mrs miggins radio alarm goes off 3 doors down and you both have the misfortune of radiolinking with only default settings, turn it can trigger either household alarm if one goes off in a different house.

Waiting on the trainer materials to expand on this, soon as I get them I'll share them here.

 

[littlespark]

Yes. Aico have “house coding” to match them up within a house, but if that hasn’t been done....

just drop down a couple of heads to see if they are RL. They’ll have an additional module fitted with a short white antennae wire. Or the base has been changed. Will have a blue(?) led on side and the house code button.

or count the cables that are connected in the base for interconnect wire.

 

[Ziggie]

If the smoke alarms are powered from a different supply to the building they are in, then there should at least be warning notices that there is more than one source of supply.
Though I don't see the purpose or reasoning behind having smoke alarms interlinked between separate buildings.
Further investigation would be beneficial.

The advantage of sharing the alarm would be if an occupant was elderly or in poor health then telling the neighbours might be a very good thing.

 

[Lister1987]

If the smoke alarms are powered from a different supply to the building they are in, then there should at least be warning notices that there is more than one source of supply.
Though I don't see the purpose or reasoning behind having smoke alarms interlinked between separate buildings.
Further investigation would be beneficial.

The fundamental principle behind fire detection is all about early warning. By not interconnecting, you're not making use of the early warning that interlinking can provide.

The principle works the same in buildings on the same site. If you've ever been to a large site (hospital is the best example) then you'll likely hear 2 alarms, 1 for fire in the immediate area (get out now) and 1 for fire in adjacent areas (prepare to evacuate). Obviously in domestic systems we don't have the dual tone (for fire) but the fundamental principle is the same; early warning.

Personally I would interlink and educate the user. You coul use a -1 system in place of -6 if you wanted the 2 tone function found on -1 systems.

 

[loz2754]

The fundamental principle behind fire detection is all about early warning. By not interconnecting, you're not making use of the early warning that interlinking can provide.

The principle works the same in buildings on the same site. If you've ever been to a large site (hospital is the best example) then you'll likely hear 2 alarms, 1 for fire in the immediate area (get out now) and 1 for fire in adjacent areas (prepare to evacuate). Obviously in domestic systems we don't have the dual tone (for fire) but the fundamental principle is the same; early warning.

Personally I would interlink and educate the user. You coul use a -1 system in place of -6 if you wanted the 2 tone function found on -1 systems.

I appreciate this principle. But in this situation, it is stated that the flats are self contained and independent from each other, other than being owned by the same landlord.
It would be like me and my neighbour, and his neighbour 2 doors down, all having interlinked smoke alarms. All supplied electrically from my house.
At least that's what I understood from the OP.

 

[Lister1987]

I appreciate this principle. But in this situation, it is stated that the flats are self contained and independent from each other, other than being owned by the same landlord.
It would be like me and my neighbour, and his neighbour 2 doors down, all having interlinked smoke alarms. All supplied electrically from my house.
At least that's what I understood from the OP.

Fair point, what would does the FRA say? Communal areas should be on a -1 system with Sounders near each flat in any case, so you could make use of that extending into each flat with 2 sounds (immediate evac or prep to evac).

Other factors may come into play with the occupants (elderly, hard of hearing) with may favour linking all alarms.

Alarm system should come from the communal supply in a HMO/Shared building at any rate.

 

[Ziggie]

If the smoke alarms are powered from a different supply to the building they are in, then there should at least be warning notices that there is more than one source of supply.
Though I don't see the purpose or reasoning behind having smoke alarms interlinked between separate buildings.
Further investigation would be beneficial.

Interlinked smoke alarms don’t necessarily have one source of supply. My sensors are powered from two separate circuits off the CU and law in Scotland allows mains powered and lithium 10 year battery detectors to be interconnected.

The recent law insists that all detectors within a house are interlinked.