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FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Fire Safety => Topic started by: Tom Sutton on November 18, 2007, 07:36:14 PM
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My sister’s guesthouse is fed by two separate consumer units therefore the non-maintained emergency lighting is split between the two. After a recent visit from the fire officer he implied that the complete emergency lighting should be activated if either supply is lost. Surly if one supply is lost and its emergency lights activate this is sufficient as the other good supply will maintain its normal lighting.
What has happen to common sense?
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like you say if the power in one buidling is still on then what would be the point of having the emergency lighting on in that building?
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Personally I'd ask him to explain his reasoning for the request. Is the lighting all mixed together or are the areas served by the consumer units clearly seperate? If they are seperate then I could see no good reason for his concern (no different to having 2 lighting sub-circuits). In which case I'd probably ignore him (as long as I could justify it through my FRA). If the two sets of lighting are all mixed together then could it possibly cause confusion during the hours of darkness if some of the lights came on but others didn't?
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Very many premises have the emergency escape lighting incorrectly wired- as we all know the emergency lighting should be configured to ensure that if any local lighting sub circuit should fail then the non maintained emergency escape lighting IN THAT SAME AREA should operate. Sorry for shouting but so many places are incorrectly wired with the non maintained emergency escape lighting going back to its own circuit breaker on the Distribution board. In so many cases including some very posh hotels with multiple distribution boards I have even seen non maintained emergency lights powered from distribution boards in a different part of the premises and even recently on a different phase.
Making them all work together is not the answer though- we need to ensure that they work on local subcircuit failure.
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It seems to be a speciality of licensed premises that if the sub-circuit for the lights in the toilets fails the emergency lighting comes on in the kitchen!
Tw, it should suffice to check that, if the lighting fails in one area, the EL comes on to cover that area.
Do note Johno's comments though.
Also, hotels and guest houses often prefer to have maintained lighting so that guests who choose to wander about in the night don't have to fumble about for switches in the darkness. This may be worth considering for health and safety reasons.
Stu
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Thank you all for your responses and I will direct my questioner to this page for further information.
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As we all know the safety lighting, actually escape lighting, should operate in the event of a mains or subcircuit power failure.
Test the system by turning on all lights pull a fuse one at a time and ensure that where the lights has gone off that a safety light has come on and provided the level of lighting required. Escape lighting would only be required in certain areas such as internal and external escape lights.
Don' t forget that one can use borrowed light in the event of a power failure.
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Don' t forget that one can use borrowed light in the event of a power failure.
It concerns me about the use of 'borrowed light' when designing emergency lighting. In my home locality we have had no less than 5 supply interuptions since the beginning of this year ranging from a few minutes to one of two hours and another of over two and a half hours. This affected the whole neighbourhood. So at my own church's Parish Centre there would have been no 'borrowed light' from the nearby industrial estate. As a result I've had to revise the FRA and recommend the extension of emergency lights to outside the building where before the 'borrowed light' was considered sufficient.
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If you have a fire in the building at the same time as a general area power cut there could be a problem. But how far is it reasonable to go in planning these things and are the principal concerns in respect of a fire risk assessment or would it be more relevant to the general H&S premises risk assessment?
Sounds like a case of the system for review working exactly as it was intended though.
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As we all know the safety lighting, actually escape lighting, should operate in the event of a mains or subcircuit power failure.
Test the system by turning on all lights pull a fuse one at a time and ensure that where the lights has gone off that a safety light has come on and provided the level of lighting required. Escape lighting would only be required in certain areas such as internal and external escape lights.
Don' t forget that one can use borrowed light in the event of a power failure.
Sorry to disagree, but you should not break a live circuit by pulling the fuse (NIC EIC rules). If the distribution board has MCB's then fine, you're only turning off the circuit, but by pulling a fuse, you do run the risk of an electric shock, and probably creating a spark (uncontrolled ignition source?)
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that would be in my ideal world Dragon Master but unfortunately i still have to pull hundreds of fuses every year to test e/lighting even the big old porcelain ones.
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If you have a fire in the building at the same time as a general area power cut there could be a problem. But how far is it reasonable to go in planning these things and are the principal concerns in respect of a fire risk assessment or would it be more relevant to the general H&S premises risk assessment?
Sounds like a case of the system for review working exactly as it was intended though.
There is "emergency lighting" and there is the sub-set "escape lighting." When discussing EL (emergency or escape?) with occupiers I have a tendency to broaden the analysis to emergency lighting, including general health and safety in the discussion. Wht not?
Stu
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yes I tend to lump it together under a the term emergency escape lighting cos then everybody knows what I am talking about. It then includes the fittings such at points of emphasis, in lift cars, in lift motor rooms, in electrical switch rooms, at first aid points in one hit. But it may be technically imperfect.
The only time I find it gets less relevant is where there is a mix of systems in a building for example where some key safety lighting is on a inverter / generator backup and only core escape routes have what is then best described as escape lighting.
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From my questioner,
Thanks to you and your friends help on my question, I found it very helpful.
A couple of points that were raised;
The fire officer was doing a general risk assessment to make sure my sisters business complied with the new fire regs. We are now in the process of fitting a new fire alarm and a couple of extra emergency lights.
The guesthouse is relatively small with only 7 letting rooms and although an extension was added prior to purchase with the 2nd consumer unit the lighting is zoned, ie one covers middle & top floors and the other the ground floor. That's why we found his request a little odd.
Thanks once again and if you think any thing else may be relevant please don't hesitate to forward it.
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have you considered indicating the escape route with photo-luminscent signage. if i the natural light or the powered light in the areas are of a good standard in normal conditions, in the event of a power failure these types of signs will provide a high standard of direction without the need to install full emergency lighting throughout. IMHO you should contact www.jalite.co.uk who are the leaders in this industry with reference to their AAA signs for further advice
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Photoluminescent signs on their own cannot provide sufficient luminance to provide escape route illumination. Photoluminescent Signs are only one component of a safety wayguidance system. The other component is continuous illumination through out the escape route. This should be provided by a traditional electrical system or a photoluminescent system in accordance with BS 5266 Part 6 or ISO 16069. As I have said many times the illumination of signs is a requirement to ensure the sign is conspicuous and legible under mains failure emergency. Escape route illumination must deal with ensuring evacuees can move securely throughout the means of escape.
This is why Photoluminescent escape route illumination is required in every staircase within multi story building in New York, because it provided excellent assistance during the catastrophic events of 9/11.
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have you considered indicating the escape route with photo-luminscent signage. if i the natural light or the powered light in the areas are of a good standard in normal conditions, in the event of a power failure these types of signs will provide a high standard of direction without the need to install full emergency lighting throughout. IMHO you should contact www.jalite.co.uk who are the leaders in this industry with reference to their AAA signs for further advice
Les
Does the photo-luminscent signage work, say at 4 oclock in the morning, when the the escape routes have been in darkness for a few hours? Will these signs illuminate the escape route like safety lighting will?
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Sadly not - if you want a way guiding system to work at any time you'll need constant artificial lighting.
To balance the commercial plugging jalite are not the only people in this field - Everlux are another manufacturer who are becoming more widely used
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When is an escape route in total darkness for a few hours prior to an emergency? May I suggest that this only happens when the place is unoccupied. If it does happen then I would suggest that the escapee would have to turn the lights on to escape? Then worst scenario at this particular time the mains fail? Very unlikely.... Any way Photoluminescent technology is so advanced now that it is provided on long haul aircraft with luminanance duration of over 12 hours with excitation light source as low as 25 Lux.
In a traditional hard wired electrical system you have much more onerous maintenance regime as well as lots of places where Mr Murphy can reign, batteries, bulbs,generators,wiring rodents installation etc etc. The big one is when smoke obscures the ceiling... Very likely
The main problem with Photoluminescent systems are that they appear to be too good to be true, but in 9/11 this technology was proved to greatly assist evacuation in the staircases of the twin towers. So much so that by prescription these systems have to be fitted in all commercial building staircases in New York over 75 ft.
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To balance the commercial plugging jalite are not the only people in this field - Everlux are another manufacturer who are becoming more widely used
i neither work for jalite nor intended to give a commercial plug.... having not heard of Everlux.. my intention was to open an alternative to the question that was being raised. and my experiences with the fore mentioned company have always led me to have been given a proffessional free high level of advice on any occassion that i have asked for it.
therefore it was my intention to lead the questionairre in a direction that could be of benefit.
my appologies if it was interpretted differently.
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On topic:
Some/several escape routes do have artificial lighting off at normal times, with fire escape light switches at each level to turn on normal lights and non maintained escape lighting units for power failure.
Even new or refurbished premises sometimes keep this practice, but replacing the reliance on light switches with PIR activation.
This is because, especially in larger buildings, it is prohibitively expensive to keep stairs mainly or solely used for emergency purposes lit 24/7 or even just occupied hours year round and RP's will not do it.
Plus just the photoluminescent signs alone are not sufficient for escape & despite extolling the benefits of a full way guidance system most RP's won't go for it - I've only ever got one true system in for a specific risk area of a building.
Off topic:
I didn't mean you were plugging it per se, but Jalite has entered the dictionary as a common term for photoluminescent material just as Hoover is commonly used as a term for vacuum cleaners.
This is of course due to their high market share resulting from high standard of their product, continuous development & very good technical support and guidance documents - their illustrated guide to fire signage is a great tool to give end users as is easier to understand and cheaper than copies of BS 5499-4.
But to paraphrase the BBC ads "other manufacturers are available". Most don't achieve the performance of Jalite AAA, but everlux/masterlux by Sinalux in Portugal has a very good range with good performance. Not known to end users, but being used by a number of companies in the fire trade
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On Topic,
At all these times when lights are on whether continously, intermittently or for just short duration photoluminescent materials are being energised. Good Photoluminescent materials conforming to the performance criteria in ISO 15370 from whatever source will energise at only 50 lux (far lower light level than required for safe working and best practice in escape routes) and be saturated ie maximum performance after a total of only 15 Minutes of excitation. Yes really it is too good to be true.
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The problem with PLM's is that it only takes a relatively small amount of fire smoke to obscure them because of the very low luminance levels measured in mcd/sqm. When ambient lighting is off or low, PLM's light intensity will start to decay just like the luminous dial of your watch in the dark. You need good lighting to charge PLM's in first place. Shaded areas in a building may not provide enough daylight or artificial overhead lighting. PLM's have their place but are not a panacea for all evils. Lit signage offers much greater visual conspicuity generally, plus UPS backup to maintain lit signs for 180 minutes if power is off. UPS emergency packs can also be fitted into lighting designed to provide the right amount of light down egress routes to fire exits.
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Nothing works in smoke, Your eyes and your lungs do not work in smoke. Emergency Lighting becomes obscured in smoke and it gets dark well before smoke makes the lower areas of the escape route completely useless, this is when low proximity safety wayguidance systems become extremely valuable whether electrical or photoluminescence. Funny you should talk about photoluminescent watches as this was used to fantastic advantage by one evacuee in the 9/11 emergency to help a group find their way.
Photoluminescent safety waygudance systems do not require all the extral power consumption equipment and it is adequately tested every time the normal lights are switched off. So simple and effective.
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Smoke control systems are designed to create tenable conditions (say light to medium fire smokes as described by BRE and FAA) approx 2 metres up from floor level in major buildings today and stair pressurisation systems generally do a good job down fire-stairs in keeping smoke out. In this context tenable means transit to the nearest fire exit or safe refuge.(911 was an exceptional and hopefully one off event.)These smoke control systems helped many thousands of people get out in 911, plus the North American EL minimum illumination standard of 10Lx. In UK it was 0.2Lx up until recently and even now is only 1Lx. As a reference normal office lighting is around 3-400Lx. It takes your eye some minutes to adjust from 3-400Lx to 10Lx. 1Lx and lower, is just not seeing the problem. You need to get out as fast as possible. Also bare in mind many building Evacs are in clear air. You really need to see approx 10 metres in front of you to transit confidently and quickly, which means being able to see illuminated wayfinding signage, particularly if your not familiar with the building.
Unfortunately we continue to specify and mandate these lit wayfinding systems (EL and Exits) at ceiling level, where the fire smoke will layer and attenuate both emergency lighting and lit signage. Not very conducive to fast escapes.
The better engineered solutions provide a mix of lit powered and non-powered (PLM's) low level wayfinding and smoke control systems. There are also some very interesting developments using locatable broadband sound in this solution mix. You can hear thru medium to heavy fire-smokes, even when visibility is down to only 3-5 metres.
PLM's have a place in this solution but are definitely not a panacea for all evils.
PS. I tried to using my watch and trod on my cat! Pity she really can see in the dark!!