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Topic Title: maintained emergency light testing
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Created On: 17 March 2013 10:34 PM
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 17 March 2013 10:34 PM
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djp1000

Posts: 1
Joined: 17 March 2013

I've been asked to look at testing some emergency lighting in an office and to be honest it's not something I do a lot of. The office has about 50 recessed fluorescent light fittings about 10 of which are maintained emergency lights. The lights are split into roughly 5 areas with 2 EL's in each. Each area has it's own test switch for the EL's. In order to test the EL's I have had to switch off all the lights at the switch and then deploy the test switch, otherwise all of the lights still had a switched live supply and stayed on. Is this how it's normally done? I'm asking because out of 10 of the EL's which were only fitted 18 months ago (not by me), only 2 came on when the test switch was deployed and they didn't stay on for long . The charge LED on all of the EL's was on as expected during normal operation and went off when the test switch was deployed. Has something not been done correct here or are battery lives really that short? Any nuggets of wisdom gratefully received.
 17 March 2013 11:32 PM
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Dave69

Posts: 447
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Who has been responsible for the emergency lights in the past 18 months?
In theory the person responsible should be carrying out a daily visual inspection to ensure each emergency lights indicators is on to ensure they are ready for operation, this never happens of course.

on a monthly basis they must be tested for correct operation by using the test switches or if not by isolating the supply to each fitting by the reverent fuse, MCB. This is only a short duration test to prove the fitting will work in the event of a power failure but the results MUST be recorded.

On a yearly basis the emergency lights must be tested for its full rated duration time, normally 3 hours and then confirm that after the duration test the indicators on the fitting illuminate once the power has been restored, this testing obviously has safety implications and should therefore ideally be carried out when no other people are in the building and at a time when the batteries in the fitting will have plenty of time to recharge before people are back in the building. A great way of saying this should be done on a Sunday at double time )) If this cant be done then only a limited number of fitting can be tested at a time and then no more can be tested until the previous tested light have had time to fully recharge/ Again the results MUST be recorded.

So first point of call is to ask to see the emergency lighting test book and records. You could also ask to see their FRA, if they have not tested their emergency lights in the last 18 months they probably haven't got a FRA

As for as the test switch operation is concerned different people have different views, some will wire them as you have described, I always wire them so the operation of the test switch removes the supply to all the light fittings on that circuit, that way there is no danger of someone operating the test switch and forgetting to turn it back on.

If the led goes off on an emergency light fitting then it should come on, check to make sure the batteries have actually been plugged in as i find it hard to believe they have really failed after just 18 months

Oh and remember it's not just the emergency lights you need to test, all emergency exit signs, etc.

Edited: 17 March 2013 at 11:38 PM by Dave69
 18 March 2013 12:10 AM
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alpelec

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Joined: 04 November 2008

Hi djp,

I used to test emergency lighting a few years ago and from what you are saying I would say that they are not wired correctly. Firstly you shouldn't have to turn off the lights to test. They normally have a permanent live and a switched live terminal. The permanent live keeps the battery charged which should last about 3 hours on failure/test. The permanent live should be there 24/7 and the test switch should break this - even when the lights are switched on via the switched live. When there is no switch a link is fitted between the permanent and switched lives. It could be the the permanent and switched lives are the wrong way around, or the fittings are not wired correctly - I have come across this before know, or the circuit wiring isn't right somehow. You will need to check the wiring on them - one area should be enough if they all do the same.
 18 March 2013 07:28 AM
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alanblaby

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Joined: 09 March 2012

I'd like to query the 3 hours duration mentioned above twice.
The 3 hours according to my books / Regs is for places such as cinemas/public houses etc, places where the public have access, for offices, the recommended duration is 1 hour.

Generally, the emergency lights available to buy are all 3 hour duration, but there is no need for a 3 hour duration if used in many places, so, would you still test them for 3 hours for such a location?
 18 March 2013 07:35 AM
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alanblaby

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Originally posted by: djp1000
Each area has it's own test switch for the EL's. In order to test the EL's I have had to switch off all the lights at the switch and then deploy the test switch, otherwise all of the lights still had a switched live supply and stayed on. Is this how it's normally done? I'm asking because out of 10 of the EL's which were only fitted 18 months ago (not by me), only 2 came on when the test switch was deployed and they didn't stay on for long . The charge LED on all of the EL's was on as expected during normal operation and went off when the test switch was deployed. Has something not been done correct here or are battery lives really that short?


Thats sounds wrong. When the test button is used, it should cut the switched supply to the lighting, and the EL section should start up within a few seconds. It should make no difference if the lighting is on or off at the time, when tested the EL should come on.
It also sounds like the batteries are nearly dead if they only stay on a few minutes.
Firstly you need to check the batteries are connected - I did an office block recently, and found 5 lights did not have their batteries connected from new. My battery supplier seems to think the batteries should last 5 years. There may be a few that fail early and others that go on longer, but a ball park 5 years is usual.
The green/red indicator light can be wrong too. I've had some which were not charging the batteries, yet the green light was lit. That will mean a new ballast/controller, which can be quite expensive for what they are, it is sometimes cheaper to buy a new fitting rather than repair the old one. Whitecroft charge around £70 for their emergency controllers, when the lights can be bought new for £100 inc. batteries.
 18 March 2013 11:53 AM
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OMS

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Thats sounds wrong. When the test button is used, it should cut the switched supply to the lighting, and the EL section should start up within a few seconds. It should make no difference if the lighting is on or off at the time, when tested the EL should come on


Steady - this is about risk management - you may be creating a far bigger hazard by plunging an installation into darknes and hoping, fingers crossed the emergency lighting you are testing does actually work.

There are plenty of systems that do not switch off the mains to normal luminaires when testing emergency luminaires.

Removal of permanent emergency supply to the invertor will usually drop out the switched line and you'll see the lamp operate (hopefully for duration) at a much reduced output (circa 10% of normal lumen output).

When general lighting is on, the lamp remains on (at reduced output) - when off, it should illuminate (again at reduced output).

There is nothing in BS 7671 that requires the general lighting to go off when testing emergency lighting - although in many cases it is specified that way for convenience of users (and in some cases fire officers who are usually incapable of undertanding what they are looking at and what BS 5266 actually requires) and in some cases as an aid to commisssioning where illuminance levels are being taken.

Regards

OMS

Edit to correct BS reference for emergency lighting

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Failure is always an option

Edited: 18 March 2013 at 07:52 PM by OMS
 18 March 2013 12:09 PM
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unshockable

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I think it may be as simple as getting switch and permanent live mixed up, easily done.

Permanent live is often marked L1 and switch live L, I can see it as counter-intuitive, without reading the instructions one can get to the end with a lot of work to do! Won't this also put them into test mode every night and wreck the batteries?

Simon
 18 March 2013 01:05 PM
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OMS

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Originally posted by: alanblaby

I'd like to query the 3 hours duration mentioned above twice.

The 3 hours according to my books / Regs is for places such as cinemas/public houses etc, places where the public have access, for offices, the recommended duration is 1 hour.

It actually talks about buildings where early re occupation is required in order to mitigate other hazards - like dumping 200 drunks on the street in a town centre with nowhere for them to return to


Generally, the emergency lights available to buy are all 3 hour duration, but there is no need for a 3 hour duration if used in many places, so, would you still test them for 3 hours for such a location?


No - they only need to meet the design duration stated on the design, installation and commissioning (and possibly verification) records


Regards

OMS

-------------------------
Failure is always an option
 18 March 2013 05:58 PM
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Dave69

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I think if you read the OP you will see that is says when the test switch is operated all the indicators on the E/L on that circuit go out, so there is no wiring problem, it is either the batteries have not been pluged in, the batteries are shot of the fitting is faulty.

Once a year all emergency lights should ideally be tested to their full rated duration, even manufacturers reccomend this as it is an easy way to see how the battery performs and as alomost every E/L apart from the cheap rubbish are rated for a min of 3 hours duration the fittings should be tested for three hours.

And OMS I cant be bothered to go out and check now but isn't BS5839 concerned with fire alarms
 18 March 2013 07:51 PM
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OMS

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And OMS I cant be bothered to go out and check now but isn't BS5839 concerned with fire alarms


It is - that'll teach me to have a conversation with a colleage whilst typing a response

It should of course be BS 5266 -

The luminaires however should be tested for thier design duration - not for the selected autonomy. If a system only needs one hour duration and a 3 hour fitting is installed, it only needs testing for 1 hour

Regards

OMS

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Failure is always an option
 19 March 2013 07:55 AM
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Fm

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I have to evac a building based on the occupancy levels , so 120 seconds?
AAbattery anyone
 19 March 2013 10:04 AM
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OMS

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Originally posted by: Fm

I have to evac a building based on the occupancy levels , so 120 seconds?

AAbattery anyone


I think you may be mixing up criteria.

For building evacuation, you have:

RSET - required safe evacuation time - ie how long it would reasonably take the occupants to get out based on accupancy numbers, occupancy/user type and any physical building constraints - stair or corridor width

ASET - Available safe evacuation time - ie how long the building can maintain tenable conditions for that escape time determined from RSET

So, if you can reasonably get all the people out in 120 seconds, then with a factor of safety of say 3 then your design neds 6 minutes.

Typically, as no aspects of the structure etc act independantly, we arrive at a minimum of 30 minutes seperation - you'll see this on doors, partitions etc with higher risk compartments - boiler rooms going to say 1 hour.

The mergency lighting criteria aren't based on ASET and RSET as they also need to capture marshalling, post evacuation investigation and returning the building to a normal state following a false alarm. It also needs to consider a second incident occuring directly after the first - which is why we get to normally 1 hour for most buildings and 3 hours for buildings that are likley to need early reoccupation (Law courts or a town centre hotel would be examples)

An AA battery probably wouldn't do it -

Regards

OMS

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Failure is always an option
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