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Topic Title: idea for emergency lighting
Topic Summary: is there anything wrong with this
Created On: 29 November 2012 05:47 PM
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 29 November 2012 05:47 PM
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keithredpath

Posts: 424
Joined: 30 March 2002

The client has installed very expensive emergency lighting along an escape route. Every second fitting is an emergency light. On measuring the lighting levels we now find them to be too low. Basically we need every fitting to be an emergency light. To save on buying 12 new fittings, would it be ok to fit a small ups unit in a cupboard and supply all existing non emergency fittings via the ups.

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keithredpath
 29 November 2012 06:05 PM
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savcab

Posts: 53
Joined: 19 June 2010

what's the lux level on the centre line? I'm sure an I obstructed escape route minimum requirement is 0.2 lux although 1 lux recommended. depends on ceiling heaths and size of route for spacing. I'd get a lighting designer from a wholesaler to give you a free design to check it out.
 29 November 2012 06:10 PM
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Avatar for OMS.
OMS

Posts: 19763
Joined: 23 March 2004

You could only use a UPS solution if the cabling is fire rated !!

What did you measure it with - current BS requirements for unobstructed escape routes are low - very low in fact. Unless you have a cosine corrected lux meter operating down to those levels then I'd wary of condeming a solution based on instrument error alone.

If the uniformity of the general lighting is reasonable, then I'd be very suprised if alternate emergency conversions fail a lux level test

Regards

OMS

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Failure is always an option
 29 November 2012 06:45 PM
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lyledunn

Posts: 633
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Kieth,
5266-1 2011 requires minimum of 1 lux on centre line for escape routes. If the system has only recently been installed then surely photometric data would be available. As OMS says, sometimes not so straightforward to get accurate direct measurement. Dont like the idea of UPS; sounds a bit jerry-built but I guess if it works and complies then hey-ho!

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Regards,

Lyle Dunn
 29 November 2012 06:52 PM
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OMS

Posts: 19763
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Dont like the idea of UPS; sounds a bit jerry-built but I guess if it works and complies then hey-ho!


It's a pretty common solution in a variety of sectors/applications - but in this case I doubt there is fire rated cabling in place to support the UPS output to the luminaires.

Essentially, the UPS is just a central battery system kicking out 230V AC (ish)

regards

OMS

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Failure is always an option
 29 November 2012 07:19 PM
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lyledunn

Posts: 633
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Sorry Keith, didnt mean to torpedo your idea, that was churlish of me . I am sure that it could be reasonably deployed. However, your post inferred a recent installation that has been designed and installed in a certain way. Supplanting another alternative methodology is probably perfectly legitimate. However, I grew up with central battery systems, installed and maintained them through the years and then helped the younger fellas rip them out!

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Regards,

Lyle Dunn
 29 November 2012 07:58 PM
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AJJewsbury

Posts: 11587
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Would the UPS itself (or the cupboard it's in) have to have a degree of fire resistance too? (there doesn't seem to be much point having fire rated cables if the inverter has melted).

-Andy.
 29 November 2012 08:16 PM
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Zs

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Originally posted by: lyledunn

However, your post inferred a recent installation that has been designed and installed in a certain way.


Lyle, having recently experienced something similar, and having become bad-cop who just tells everyone what is wrong (no fun), I expect that you are being very kind to the installer of the original set-up in suggesting a design took place at all.

But I agree with previous posters and would be surprised if the required lux level to comply isn't already being met.

However, having tested the emergencies on my similar case I'd like to say something about common sense in these applications. Our eyes take a good while to adjust from light conditions to dark and I firmly believe that the best test of emergency lighting is to plunge the place into the gloom of the emergency lighting and see if you can find your way out. No lux meter, however it is calibrated can do that for you. and 1 lux is very low.

Keith, If the UPS option is the tidiest available to you then I would go for it even if it is a temporary measure. Often a UPS is better maintained than the emergency lighting system in a building so I reckon that is not a bad call at all. You've just got to get people out. On my job we have deployed a whole load of glow in the dark signage in addition to the lighting changes and they are marvellous. The boiler room there is horribly dark at the moment, pending changes, and it is an L shaped area with which I am not familiar. it is a big plant room with pipes and obstructions. I got out easily, alone, with only the glow in the dark signs. In future I will always use them. Position them perfectly so that the user can walk right under them along a passage and they work beautifully.

Zs
 29 November 2012 08:17 PM
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OMS

Posts: 19763
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You'd usually put it in a low risk location (or individual fire compartment) Andy

Emergency lighting equipment isn't usually "fire rated" in the sense that it can withstand flame for a given time - if the fire's in that compartment, then all bets are off - the idea being that you maintain services in other compartments just by means of fire resistant cabling.

In a central battery system it makes sense to protect the source of supply

Regards

OMS

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Failure is always an option
 29 November 2012 10:35 PM
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peteTLM

Posts: 3187
Joined: 31 March 2005

why are the light fittings expensive?
2 situations- decorative enclosures but normal/ cheap guts.
- normal fittings- expensive inner guts (LED etc)

Could just buy the gear trays from the EM fitting and change the inners.

As the others have said, 1 Lux is a tiny amount of light. Think 3/4 full moon light- is what ive heard it compared to.
What fittings and spacings are we talking about here??

P

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Lack of planning on your part doesn't make it an emergency on mine....

Every man has to know his limitations- Dirty Harry
 29 November 2012 11:17 PM
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jamieblatant

Posts: 513
Joined: 11 January 2006

Can you see to get out in the dark

If the Anwser is yes it's ok

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