Emergency Light in Electric Cupboard - advice

[FatherDougal]

Hello,

I've been asked to install an emergency light in the Electric cupboard which should be able to act as a normal light (i.e. switch on/off as required) and also independently when the power is turned off - so that the worker can see what is happening in the cupboard.

I'm trying to figure out what is the best way to install this.

Mains power available:
Switch off - emergency battery should be charged/maintained.
Switch on - mains power should illuminate the light.

Mains power unavailable:
Option 1 - Discharge the battery across the bulb until power is available when the switch position will then dictate bulb operation.
Option 2 - Switch still controls operation of the bulb.


I'm trying to figure out how this can be set up without the battery backfeeding into the consumer unit. Is this even a problem?
Which of the options are the best to opt for or feasible?

At the property I have currently:
- DPDT switch
- LED strip lights
- AC to 12V DC converter (cannot remember precise details, but it is suitable for the LED strips)
- Single LED downlight with battery pack
- Cabling, conduit, etc...

Any advice on how to go about this?

Thanks.

 

[ericmark]

A maintained emergency light will auto come on with power failure or when switched, they should last 4 hours, with units to convert fluorescent lights you can fit lager battery packs, but with power off the battery is being discharged.

The way I have done it is with a touch, if dark movement switches it on, also switches on with power failure, and can be removed from charge station to see better if required, plus can be switched off, the one in house came from Lidi I would say that is best one, in the caravan it came from Asda. Lidi one is flat and looks more like an emergency light, Asda one is touch shaped. So all I would do today is fit a socket and torch plugs into socket.

 

[FatherDougal]

Thanks - what is a touch?
I was hoping to get away with using the parts I have, instead of purchasing more.

 

[flameport]

Any advice on how to go about this?

Buy this or similar:
https://www.lampshoponline.com/led-emergency-maintained-bulkhead.html
Connect mains supply to it, and a switch between the L&SL terminals.
With mains power available, the switch turns the light on/off
When mains fails, the light switches on and is powered from the internal battery.

Lashing things up from a random selection of parts is not likely to work well or at all.

I've been asked to install an emergency light in the Electric cupboard

By who?

the worker can see

What kind of installation is this?

 

[Taylortwocities]

Yes, as flameport says. Buy a ready made emergency light. They are only £12 or so. Wire direct to existing 6A lighting MCB. Fit a switch that will interrupt the power to the EM and the light will come on when you need to see in the cupboard.
The light will come on when power fails.

Simples

Meerkat

• Taylortwocities
• 11 Dec 2009
• 53

 

[boringoldcodger]

what is a touch?

I imagine Eric meant a "torch" (a word he uses near the end) .

 

[FatherDougal]

By who?

A relative

What kind of installation is this?

Private residence

 

[FatherDougal]

Yes, as flameport says. Buy a ready made emergency light. They are only £12 or so. Wire direct to existing 6A lighting MCB. Fit a switch that will interrupt the power to the EM and the light will come on when you need to see in the cupboard.
The light will come on when power fails.

Yes, this is a more simple solution than what was requested - they wanted the emergency light to only illuminate if they turned it on.

 

[EFLImpudence]

they wanted the emergency light to only illuminate if they turned it on.

If you mean that when there is a power cut/loss, they want to then manually turn on the emergency light,

then a simple battery light would seem to satisfy that requirement which would not be what is meant by an "emergency light"..

 

[FatherDougal]

If you mean that when there is a power cut/loss, they want to then manually turn on the emergency light,

then a simple battery light would seem to satisfy that requirement which would not be what is meant by an "emergency light"..

They had grand ideas... As the cupboard is used to store a few other things, they wanted a light in it to use as per a normal light setup. They then wanted the light to still work, if the power was cut and they (or an installer) needed to work in the cupboard. There is a Sky box, network hub, etc plus some vacuum parts, brushes etc in there.

But yes, as I'm writing this thread and reading the replies I can see that there are simpler ways to meet their requirements. I mistakenly said emergency light in the original post as that is what I was finding when I search for an emergency light.

If you mean a 100% battery powered light (not charged by mains power) then I'm not sure that this is what they would want.

What is the lifetime of the batteries in emergency lights?

 

[Taylortwocities]

What is the lifetime of the batteries in emergency lights?

They are designed to operate for st least 3 hours. The maker will say the period on the product spec.

 

[EFLImpudence]

What is the lifetime of the batteries in emergency lights?

It's only three or four hours when lit, but is recharged when the power comes back.

It seems you just want an ordinary mains light for use in the cupboard.

There isn't much point having an emergency light in a cupboard.
Oh I suppose there might be if the consumer unit trips, but a torch...

 

[JohnD]

old emergency lamps used to have a small fluorescent tube, gear, and SLA or NiCad batteries.

But the modern ones, with LEDs and sometimes Lithium or NiMH batteries, last much, much longer. I actually don't know how long, but I've seen them burn for more than 24 hours without dimming. I suspect the batteries are now so cheap the manufacturer's won't save much by minimising them to a 1-hour power.

I have half a dozen "camping" LED lanterns in my shed, they take a couple of alkaline or rechargeable AA batteries and easily run all night. You just turn them on at need. I have an idea they were a few pounds each.

No need for emergency lighting now, except on stairs.


examples

 

[FatherDougal]

Sorry - maybe I should have been more clear - do the rechargable batteries in an emergency light have a lifespan before they stop holding the charge?

 

[JohnD]

Yes. I had "professional" ones in commercial premises, I think they were routinely replaced at 5 years, and were tested monthly. Any that failed test would be replaced anyway, but IIRC it was rare.

The more modern ones seem better.

As they spend almost their entire lives on "float" charge I should think they are in pretty ideal conditions.

In the home I think I would go for replaceable alkaline cells and change them when they got dim. It would be much cheaper.