consumer unit advice

[electrician4u]

Just had a look at a installation guide from Hager about wiring consumer units and they suggest it's ok to put a smoke detector circuit with a lighting circuit and shower on the same RCD. I thought that was strictly not recommended. from my experience it's the lights that trip most often.any thoughts?

 

[telectrix]

smoke detectors are best connected in to a frequently used lighting circuit, reason is , if the MCB trips, client will be without lights and get it sorted.

 

[mickys86]

smoke detectors are best connected in to a frequently used lighting circuit, reason is , if the MCB trips, client will be without lights and get it sorted.

Tis the way I've been taught as well 

 

[brucelee]

hi mate
you can do it either way but tels way will be more likely to be noticed by customer

 

[telectrix]

the problem with having a dedicated circuit for smokes is when her indoors burns the dinner ( so you know if you don't smell burning, it's salad day) , it's too easy for mr. numpty to isolate the smokes, thus rendering them useless ( because he can't be bothered to replace the batteries either. if in a lighting circuit, though, he'll soon reset it after he's fell over the cat in the dark.

 

[brucelee]

dedicated RCBO or regular used lighting circuit BUt I would always go for lighting circuit for domestic as both are stipulated in elecys guide to building regs and also manufacturers info
They both prefer lighting circuit
elecys guide say with a means of isoltion but no means of switching off so a unswitched fused control unit off the lighting circuit
the detectors and alarms are required to:
a) be linked so one will operate the other
b) be permanently wired with a independent circuit to the distribution board( ccu), OR PREFERABLY SUPPLIED FROM A LOCAL REGULARLY USED LIGHTING CIRCUIT, ( There SHOULD be a means of isolating the supply to the smoke alarms without switching off the lighting )
c) have a stand by power such as a battery or capacitor

Note mains powered smokes may be interconnected by radio links

 

[electrician4u]

That's all very well when electric smoke alarms have a battery backup, but what about mains only? surely must be on its own supply?and would any electrician connect to a light circuit, then put an unfused spur in the smoke alarm circuit-seems messy and an unnecessary expense.good point made about nuisance activation and the probability of it being switched off permanently though.

 

[malcolmsanford]

That's all very well when electric smoke alarms have a battery backup, but what about mains only? surely must be on its own supply?and would any electrician connect to a light circuit, then put an unfused spur in the smoke alarm circuit-seems messy and an unnecessary expense.good point made about nuisance activation and the probability of it being switched off permanently though.

Would you be thinking in a domestic situation of fitting Grade E smokes, most fire/LABC insist on Grade D for dwellings not over 3 stories.

 

[electrician4u]

i personally would fit with a battery backup but i've seen mains only connected, especially commercial and industrial and sometimes customers buy their own gear for me to fit

 

[malcolmsanford]

Well yes on commercial/industrial you will have the smoke via a detection panel and that as the battery back up.

Be careful of fitting non grade D type in domestic as they may not be approved by the LABC/Fire department and the BS 5839-6 recommends type D for dwellings not above 3 stories.

 

[electrician4u]

thanks for advice. i've learned something new.slightly troubling is if you look in Electrofix/Srewfix they sell smoke alarms with or without battery backup with no warning of use and even same model type.

 

[laws]

sorry could you just explain if you mean dipping the smokes in to the same MCB as lights or feed the smokes off one of the lights. im sure its the first but just clarifying

 

[malcolmsanford]

sorry could you just explain if you mean dipping the smokes in to the same MCB as lights or feed the smokes off one of the lights. im sure its the first but just clarifying

Either will be acceptable.

 

[marksparky]

but u must be able to isolate the smokes without affecting the lighting, i usually fit a double pole key switch surface mounted beside the consumer unit labelled as smoke detectors and feed it off 1 of the lighting circuits, i used to wire it on a circuit of its own but now i feel there is a better argument for wiring off the lights

 

[Des 56]

but u must be able to isolate the smokes without affecting the lighting, i usually fit a double pole key switch surface mounted beside the consumer unit labelled as smoke detectors and feed it off 1 of the lighting circuits, i used to wire it on a circuit of its own but now i feel there is a better argument for wiring off the lights

That may well be the result when they are unplugged from the base