smoke alarms, your opinion

[sparky40]

Hello All'
I have recently been told by my boss that somke alarms were to be connected to a regularly used lighting circuit, not on its own individual circuit, as I had done .
I questioned this to my 'superior' and they said that the N.I.C had told him that there were problems with people isolating the alarms and leaving them off.
I fully understand the reasoning behind this ,but I still believe that the way they were wired was ok. ( page56 of OSG )'

Any comments ???
_____________________________
lynda, moderator

please note forum rule 20, your post has been split

 

[plugwash]

own circuit is fine per the regs but at least in a commercial environment that MCB really should be seperately locked (you can get lock devices for most MCBs iirc).

 

[breezer]

i think the op means in a house, since in a commercaila place you would not put them on a lighting cct, and also in a commercial place it would be a fire alarm, not smoke detectors

 

[simon_d]

i put them with the lights. if they were seperate and the breaker trips, it might be months before you notice and restore mains power, but if its on the lights then it gets reconnected to the mains pretty damn quick

 

[securespark]

I survey dom properties all the time.

In EVERY case where there is a smoke alarm circuit, I see the breaker down. When I enquire, it's "Oh, the bloody things keep going off/peeping/other lame excuse"

 

[plugwash]

same as people pulling the batteries out of battery powered smoke alarms i guess.

smoke alarms on lighting circuits are a bit harder to kill but i'm sure the determined will find a way.

repeated false alarms reduce the affectiveness of a protective system both by giving people an incentive to disable the system and making them take the alarms less seriously. This is a well documented but widely ignored fact!

anyone know why would properly installed mains smoke alarms be beeping, they shouldn't suffer from low batteries should they?

 

[RF Lighting]

I have seen plenty of houses with a wire sticking out of the ceiling where the smoke alarm used to be.

Maybe smoke alarms connected to the burglar alarm may be the way to go. I have these at home and there is no real problem with mains / battery failure. It would also be very easy to incorporate a tamper circuit into the system

 

[breezer]

a tmaper cct would do no good, smoke detectors for intruder alarms have no tamper connection anyway.

i have also seen mains smoke detectors beep as the standby batt is flat

 

[simon_d]

I have seen plenty of houses with a wire sticking out of the ceiling where the smoke alarm used to be.

Maybe smoke alarms connected to the burglar alarm may be the way to go. I have these at home and there is no real problem with mains / battery failure. It would also be very easy to incorporate a tamper circuit into the system

i know texecom R8 can have a fire alarm to a zone (but volt free NC). never used it myself yet

 

[breezer]

smoke detectors on intruder alarms are a waste of time, dont comply to any regs (dont need to) when alarm goes off chances are its main alarm sounder, which you may not here if it is a fire, where as the other ones have their own high frequency sounder.

also intruder alarm smoke detectors dont comply to build regs, and if they did, not every one has an intruder alarm

 

[plugwash]

I have seen plenty of houses with a wire sticking out of the ceiling where the smoke alarm used to be.

'
yeah, exactly they obviously found they couldn't turn them off seperately and took another approach.

btw how is battery backup typically handled in mains smoke alarms? are the batteries rechargable and can they be replaced when they die (even rechargables die eventually).

my guess is most mains smoke alarms are installed by electricians who are forced into doing so by building regs not at the customers request. They are then never maintained/replaced and are disabled/removed when/if they start giving trouble.

 

[RF Lighting]

The mains smoke alarms that we fit are the EI easy fit range. These just have a standard alkaline duracell battery as a backup, which can be replaced if required, but most mains smoke alarms only have a ten year life span, which the battery will usually last for.

I have seen some with a lithium cell built in, but I don't know anything about battery replacement in these units.

 

[dingbat]

I wouldn't have smoke alarms in my house. The damned things would wake you up, wouldn't they?

 

[plugwash]

The mains smoke alarms that we fit are the EI easy fit range. These just have a standard alkaline duracell battery as a backup, which can be replaced if required

and do you inform customers about the low battery indication and how to change the batteries?

 

[breezer]

problem with that is they forget in a year or so time, or deny you told them