Battery Back Ups For Fire Alarms

[Midland Retty]

Don't forget these Regs were made under the HSW Act


A good example would be in a hearing protection zone where the hearing protection sign lights up when the Second Action Level is reached


davo

Yes, it probably relates to health and safety matters rather than fire safety specifically.

Clearly there are several things we want to keep working if the power fails in the event of fire, but nothing which shuts down if a hazard has gone away.... The resetting of a fire alarm is normally done manually at the panel, then again what about a Part 6 system without a panel.?

Maybe it does apply to that? I.e; It is undesriable to for an alarm to keep sounding once the hazard (in this case smoke or flame) has gone

[kurnal]

No midland we are talking here about a backup electrical supply for an electrically powered sign or signal.

If a sign or signal is provided as a risk control measure  for a hazard that itself dissappears on a failure of the power supply then no back up supply is needed for the sign or signal.

I have seen this logic wrongly applied by non fire safety specialists in a warehouse for a large on line retailer. In this case the conveyor system used for picking led to an ambient noise level of about 65dbA. They provided mains powered  mega blaster sirens to augment the fire alarm to ensure it was audible and did not provide a back up supply for these- their logic was that in a power cut the conveyor would stop so the ordinary non boosted alarm would be audible. They overlooked the fact that a fire could occur that would affect some circuits- eg the megablasters but not other circuits atthe same time eg the conveyor.

I told them about it and they promptly and immediately took no notice at all.

[Midland Retty]

You are correct in what you are saying K  - the sounders circuit could fail , but the conveyor could be unaffected and could carry on working.

However to be pedantic the conveyor isnt the hazard in your scenario - a fire is. The fact that fire alarm isn't audible increases the risk to relevant persons being harmed by fire but doesn't change the hazard.

"8.    Signs requiring some form of power must be provided with a guaranteed emergency supply in the event of a power cut, unless the hazard has thereby been eliminated."

Whether the conveyor is working or not has no bearing on the hazard, it does have a bearing on the risk of course because clearly when the conveyor is operation people can't hear the fire alarm. Conversely the fire alarm sounders are not warning people about the conveyor, they are warning people about a fire.

Thinking on this further this my intepretation is as follows:-

Lets take Kurnal's  conveyor system. Lets imagine there are a series of amber flashing lights which flash to warn staff that the conveyor is in use. So long as those flashing lights are on the same circuit as the conveyor they wouldnt require any form of back up. If power to the conveyor fails the lights will go out too (and vice versa).

As I say I can think of other scenarios in terms of general health and safety matters, but I cant think of any occassion where it would apply to fire precautions / fire safety

[kurnal]

However to be pedantic the conveyor isnt the hazard in your scenario - a fire is. The fact that fire alarm isn't audible increases the risk to relevant persons being harmed by fire but doesn't change the hazard.

Yes I often get confused (along with others  no doubt)  by the concept of hazard as applied to a fire risk assessment. If we work to BS4422 as we have to, a fire hazard and fire risk have a very narrow definition.

3.343 fire hazard- potential for injury and/or damage from fire

3.374 fire risk- product of the probability of occurrence of a fire to be expected in a given technical operation or state, and
the consequence or extent of damage to be expected on the occurrence of a fire.

PAS 79 uses a slightly different definition of fire hazard.
3.33 fire hazard- source or situation with potential to result in a fire

So an inaudible or defective fire alarm or a locked fire exit are not fire hazards- they are inadequate risk control measures.

[Graeme]

What does the panel think the highlighted part from the Regs means?

"8.    Signs requiring some form of power must be provided with a guaranteed emergency supply in the event of a power cut, unless the hazard has thereby been eliminated."

the hazzard being the power cut itself and you could eliminate it by installing a generator?

I thinks maybe thats what it is trying to say Graeme, albeit very badly.
How do you eliminate the chance of a power cut?
Every time I read it I get more confused. But then it is Saturday morn and I'm off to Dublin's mecca very soon to see Oireland stuff Scotland and have a few bowls of Liffey Water.

Never saw that stuffing you predicted..

[nearlythere]

What does the panel think the highlighted part from the Regs means?

"8.    Signs requiring some form of power must be provided with a guaranteed emergency supply in the event of a power cut, unless the hazard has thereby been eliminated."

the hazzard being the power cut itself and you could eliminate it by installing a generator?

I thinks maybe thats what it is trying to say Graeme, albeit very badly.
How do you eliminate the chance of a power cut?
Every time I read it I get more confused. But then it is Saturday morn and I'm off to Dublin's mecca very soon to see Oireland stuff Scotland and have a few bowls of Liffey Water.

Never saw that stuffing you predicted..

Can't quite understand it really. 

[Clevelandfire 3]

You are correct in what you are saying K  - the sounders circuit could fail , but the conveyor could be unaffected and could carry on working.

However to be pedantic the conveyor isnt the hazard in your scenario - a fire is. The fact that fire alarm isn't audible increases the risk to relevant persons being harmed by fire but doesn't change the hazard.

"8.    Signs requiring some form of power must be provided with a guaranteed emergency supply in the event of a power cut, unless the hazard has thereby been eliminated."

Whether the conveyor is working or not has no bearing on the hazard, it does have a bearing on the risk of course because clearly when the conveyor is operation people can't hear the fire alarm. Conversely the fire alarm sounders are not warning people about the conveyor, they are warning people about a fire.

Thinking on this further this my intepretation is as follows:-

Lets take Kurnal's  conveyor system. Lets imagine there are a series of amber flashing lights which flash to warn staff that the conveyor is in use. So long as those flashing lights are on the same circuit as the conveyor they wouldnt require any form of back up. If power to the conveyor fails the lights will go out too (and vice versa).

As I say I can think of other scenarios in terms of general health and safety matters, but I cant think of any occassion where it would apply to fire precautions / fire safety

No these part of the regs dont apply to fire safety.

[nearlythere]

You are correct in what you are saying K  - the sounders circuit could fail , but the conveyor could be unaffected and could carry on working.

However to be pedantic the conveyor isnt the hazard in your scenario - a fire is. The fact that fire alarm isn't audible increases the risk to relevant persons being harmed by fire but doesn't change the hazard.

"8.    Signs requiring some form of power must be provided with a guaranteed emergency supply in the event of a power cut, unless the hazard has thereby been eliminated."

Whether the conveyor is working or not has no bearing on the hazard, it does have a bearing on the risk of course because clearly when the conveyor is operation people can't hear the fire alarm. Conversely the fire alarm sounders are not warning people about the conveyor, they are warning people about a fire.

Thinking on this further this my intepretation is as follows:-

Lets take Kurnal's  conveyor system. Lets imagine there are a series of amber flashing lights which flash to warn staff that the conveyor is in use. So long as those flashing lights are on the same circuit as the conveyor they wouldnt require any form of back up. If power to the conveyor fails the lights will go out too (and vice versa).

As I say I can think of other scenarios in terms of general health and safety matters, but I cant think of any occassion where it would apply to fire precautions / fire safety

No these part of the regs dont apply to fire safety.

Where do you get that from CL3? Is a fire not an emergency and is a sign not a warning of an emergency or hazard?

[Meerkat]

No these part of the regs dont apply to fire safety.

Yes they do.  The quoted paragraph 8 "Signs requiring some form of power must be provided with a guaranteed emergency supply in the event of a power cut, unless the hazard has thereby been eliminated." is taken from Part I of Schedule 1 to the Regs.  The title of Schedule 1 says it relates to Regs 4 (4) and (5).

Reg 4 (4) says "Where this paragraph applies, the employer shall ...  (a) in accordance with the requirements set out in Parts I to VII of Schedule
1, provide and maintain any appropriate safety sign (other than a hand signal or verbal communication) described in those Parts, or ensure such
sign is in place;"

Reg 4 (3) makes it clear that this paragraph applies to fire safety signs: "Without prejudice to paragraph (1), sub-paragraphs (a) and (b) of
paragraph (4) shall also apply in relation to fire safety signs where they are required to comply with the provisions of any enactment (whether in an Act or instrument)."

Regulation 2 defines "fire safety sign":

“fire safety sign” means a sign (including an illuminated sign or an acoustic signal)
which –
(i) provides information on escape routes and emergency exits in case of fire;
(ii) provides information on the identification or location of fire-fighting equipment; or
(iii) gives warning in case of fire;

[Midland Retty]

Ah, but arent we discussing the bit about that sign or signal not needing battery back up if the hazard has been eliminated by power cut,  in which case C3 would be correct, it doesnt apply to Fire Safety as there is no occassion where a fire hazard would be eliminated by power cut.

Its been a while since I went to school, but I do know fire isn't powered by electricity 

[Meerkat]

Yes we are. 

So we can't think of an example where the last sentence of para 8 "unless the hazard has thereby been eliminated" applies in a fire safety context?  Now I may well have this the wrong way round but surely that means this clause (about battery back-up being required) DOES apply to fire safety signs?

So how does that equate to "this part of the Regulations doesn't apply to Fire Safety"?

 

[Midland Retty]

Hi Meekat

I think C3 was referring purely to the bit about not having to provide some form of back up if the hazard has been elliminated only, there is no argument about having to provide back up for fire signals and signs.

Clearly from a fire safety viewpoint there is no scenario where we would not provide some form of back up for fire signals or signs as there is no occassion where a hazard would be elliminated upon power cut.

[Meerkat]

there is no occassion where a hazard would be elliminated upon power cut.

You just know I'm going to spend the rest of the afternoon trying to think of one don't you.....   

[Midland Retty]

If you manage to think of one do share it with us... we like knowledge here you clever little Meerkat you!  

[Chris Houston]

I think (by might be wrong) that there is a lot of misunderstanding here.  I don't claim to fully understand, but here is my shot at a clarification.

The risk of being cut by an electrical saw (for example) would be eliminaed in a power cut. 

So for the saw example, you wouldn't need a back up power supply for a warning sign that said "beware of the saw".  But there are no such comparisons with fire risks - the fire risk cannot be eliminated by a power cut.

The Signs and Signals regs mainly applies to fire alarms systems because they are a safety signal.