IET
Decrease font size
Increase font size
Topic Title: Smoke Alarms - dedicated circuit ?
Topic Summary: A few Other Regs Related Questions
Created On: 19 May 2009 01:13 am
Status: Read Only
Linear : Threading : Single : Branch
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 19 May 2009 01:13 am
User is offline View Users Profile Print this message



Ahll

Posts: 61
Joined: 19 December 2006

I believe Smoke Alarms should be on there own circuit and not protected by an RCD(so on the none RCD side of the CU)..have I understood this correctly ?

Can anything else be put on the same cicuit or does it have to be dedicated soley to the smoke alarm ? Can an House Alarm system use the same circuit ?

Also is there a problem with a consumer unit being mounted on a wooden board if thats how it orginally was and still is ? Would this be a big problem when an inspection is done ?
 19 May 2009 01:52 am
User is offline View Users Profile Print this message



micjamesq

Posts: 777
Joined: 23 January 2009

I believe Smoke Alarms should be on there own circuit and not protected by an RCD(so on the none RCD side of the CU)..have I understood this correctly ?

Depends on the installation method. Have a look at 522.6.6, 522.6.7 & 522.6.8.

Quick resume, cos I'm tired :

All circuits buried in a wall or partition at less than 50mm and without mechanical protection and not used by a skilled or instructed person shall be provided with additional protection by means of an RCD with an operating current not exceeding 30mA

Can anything else be put on the same cicuit or does it have to be dedicated soley to the smoke alarm ? Can an House Alarm system use the same circuit ?

Read page 16 - Power Supplies - 1.19 in the following document:

Approved Document B (Fire safety) - Volume 1: Dwelling houses (2006 Edition)

Or do as has been discussed before and install 10 year Sealed Battery Smoke Alarms.

Regards

-------------------------
E & OE
 19 May 2009 01:58 am
User is offline View Users Profile Print this message



antric2

Posts: 1267
Joined: 20 October 2006

Smokes can be put on their own circuit or on a light point .
they have to be rcd (if normal 50mm deepregs apply) protected but best method is to RCBO the smoke.If in trunking then no RCD required.
I tend to put hall stairsand landing light and smokes on a dedicated RCBO
This way if rcbo tripped, lights are off. I referr to domestic only.
Regards
Antric
 19 May 2009 05:14 pm
User is offline View Users Profile Print this message



OMS

Posts: 22864
Joined: 23 March 2004

Usually though, fixed wiring to a smoke detector is in a ceiling void rather than a wall so 522.6.6 522.6.7 and 522.6.8 tend not to apply - you would need to comply with 522.6.5 however.

So if on a seperate circuit, usually no RCD is required

OMS

-------------------------
Let the wind blow you, across a big floor.
 20 May 2009 09:32 pm
User is offline View Users Profile Print this message



Ahll

Posts: 61
Joined: 19 December 2006

Hi all thanks for the replies. The situation is that the wires run up through partictions walls(but no protection on them) and in the ceiling voids (but no protection on them)..in a domestic residence.

My brother in law has re-wired the house saying he is a 'competant person' and has asked for my advice..I didnt see how it was installed nor can I see under the floor boards(carpets already put down!).

I dont have any experinece with smoke alarms..so after reading 522.6.7 thought the circuit should be protected by an RCD...as 522.6.5 applies and not 'under supervision of a skilled person or instructed person'(I dont believe)and I dont beleive complies with Reg 533.6.6

I was concerned that he put the House Alram on the same circuit because if a problem occurs with the House Alarm it could turn the smoke alarm circuit off either automatically or manually..Does that seem resonable ?

I know smoke alarms are ok on lighting circuit but couldnt find anything about being with an House Alam. U would suggest he just leave the smoke alarms on there own dedicated circuit. and move House Alarm onto its own or another circuit. Does this seem like a good plan ? Is it safer to be on a RCD proctected circuit or not ?

Added coming to think of it I can't even be sure reg 522.6.6(V) applies !

Maybe I should also mention that this work was started before the 17th came in, so the 16th Applies but if its easy to comply with 17th, I thought that would be the best way to go. The CU is split into 2 RCD section and none RCD section and a Main ON/Off switch. So I guess if one circuit goes on RCD side All do !

As an aside..does it matter if the House Alarm on protected by RCD or not ?

Or is it a case of You would not want to put fire or burglar alarms on an RCD due to nuisance tripping ?

Edited: 20 May 2009 at 10:39 pm by Ahll
Statistics

New here?

  • To participate in discussions, please log in and introduce yourself.

See Also:



FuseTalk Standard Edition v3.2 - © 1999-2022 FuseTalk Inc. All rights reserved.

 
..