Emergency Lighting Fault

[billythecat]

The emergency lighting in my B&B is coming on at random times when there isn't a power cut.  It's never all the lights  - the number varies.  Sometimes it's just one, sometimes it's two or three (there are four in total).  They are not at their full brightness and stay on for different lengths of time - sometimes a day or two.

As an emergency system it seems to be working fine in that if I switch off the power supply, all the lights come on at their full brightness.  Does anyone know why some of the lights should come on at partial brightness at other times and does it matter?

Thanks for any help you can give me.

[wee brian]

Sounds like something is shorting out somewhere - get it fixed or it may be the cause of a fire.

[kurnal]

You need an electrician to attend. It sounds like a fault on the neutral or an earth fault somewhere else that is causing current to return via the emergency lights.
Incidentally how many lighting sub-circuits have you got- are the lights connected to work on lighting subcircuit failure (as they should be) or are they wrongly connected to a dedicated fuse or mcb on the distribution board/ consumer unit?

[billythecat]

Thanks for your replies.  I live in the Highlands so getting someone in is the last choice option because of the distance (and hence cost) involved, but I'll take your advice and call someone.

In answer to the question, there are four lighting circuits shown on the consumer unit.  When I turn off just the switch which includes the area covered by the downstairs emergency lights, they come on (but not the upstairs ones) and vice versa for upstairs.  I'm guessing/hoping that this means that it's been set up correctly.

[kurnal]

Thats how it should be set up. Good luck with the fault finding.

[Graeme]

have seen this in old fittings. very dull with maybe half a tube lit.

how old are your fittings?

[billythecat]

Hi Graeme, They were installed before my time, but I would guess that they are about 10 years old.

[John Webb]

Got any information on the maker and model number(s) of the fittings?
Do you know when the internal rechargeable batteries were last renewed? (Whoever put them in should have put the date of installation on the batteries; it does not always happen, however!)

[billythecat]

Hi John,  They're Lightsafe ELV8/NM.  I doubt that the batteries have ever been changed.  I can't see that there's a date written on them anywhere.  

Do you know how I can turn them off completely?  Because they stay alight even when there's no mains going through them, it's difficult to know which switch they're linked to on the consumer unit (if any).

I was hoping to go away for Christmas, but I've just noticed some browning on each of the fittings, so I'm worried about leaving the house in case there's a fire.  I did try to get an electriaican in, but the only one I could get hold of can't come until the end of Jan.

If I just took out one of the bulbs, would that be sufficient to break the circuit and avoid any risk of fire?

[John Webb]

The fact your batteries have not been changed may be the root of the problem. To be honest, your best bet is to have new fittings installed by the electrician, as the charger in each fitting may not be working properly because it's being trying to charge batteries well past their "best-by" date for some time.

Personally I'd just turn off the electricity - the fittings will stay on until the battery runs out, which is likely to be rather less than the 3hrs they should go for.

Your post #4 indicates that they are being run from their local lighting circuit, as indeed they should be. The only way to turn them off competely is to:
1. Turn off that lighting circuit
2. Open the fitting
3. Disconnect one of the connections between the battery pack and the circuit board - but take care, there is a significant voltage being generated to run the flourescent tube!
4. Preferably also disconnect the mains at the fitting - in some fittings the mains cable has a small socket which can be pulled off the circuit board (or from near it), but most use a terminal block in which case use a terminal block strip to take the ends of the mains cable.

If you do have new fittings installed, ensure your electrician leaves you the instruction sheets and carefully follow the instructions regarding routine checks of the lights and the replacement of batteries. Observance of these will ensure the minimum of problems in the future. It is also something you are required to do under the new fire safety legislation which came in in October 2006.

Hope this helps.

[kurnal]

Billy
The best thing you could do before going away is to pull the fuses or trip the MCB on the lighting circuits. The batteries in the fittings (should) will keep the lamp on for 3 hours then they will be flat.

The fittings conain a mains power supply, a battery charger and a battery so taking out the bulbs will not make any difference to electrical safety.

A little browning of the plastic is common but the light should not get hot - normally they just run slightly warm.

[Graeme]

billy

you'll be lucky if the battery lasts 5 mins when you turn off the mains by the sounds of it.
as mentioned get a new fitting.Porbably as cheap as fitting a new battery to a fitting that will probably have other problems too.

[billythecat]

Thanks to everyone for their help and advice.