Emergency lights..... Discuss

[SH]

I have a downstairs lighting circuit, a 1st floor lighting circuit, a Garage lighting circuit and a Loft lighting circuit on 4 off 6A RCBOs.

I also have a Smoke, Heat and CO detectors circuit on a 6A RCBO that is present in EVERY room (16 interlinked detectors.)

Now I want to fit an emergency light to every room ceiling

So thus I can wire either into the exisiting detector for that room or the ceiling light fitting in the room.

Now my question for discussion: WHich is more sensible and why?

If it makes any difference some rooms (garage / loft / downstairs shower room) have no windows.

Stephen.

[GB]

Is this a private residence, or, say, an HMO or hotel?

[Colin Bignell]

The light fitting in the room. That way, the emergency light will come on if the circuit supplying the light fails but the one supplying the detector does not.

[SH]

private residence....

[Martin Brown]

That makes no sense at all and will greatly increase your 24/7 energy consumption for what is after all a very rare event of sudden power cut.

I have two emergency lights in my property one in the living room and one in the kitchen - a location where a power fail could result in being plunged into darkness whilst holding something hot out of the oven.

A couple of other rooms have torches modified so that you can find them in the pitch dark and a pair of the wonderful but totally unappreciated

3M dayglo torches which absorb sunlight and slowly re-emit it during the night. You can buy tape with the same stuff (strontium aluminate) in on eBay - glow time is ~8 hours after a day in sunshine. eg

(no idea if that brand is any good picked as a random example)

Some emergency lights can be plugged in and will come on when the mains drops or can be manually switched off to save power until it is needed. No point in running emergency lights during daylight hours!

Definitely go for LED ones now!

I can see no point at all in installing emergency lighting in *any* of those! YMMV

[charles]

I don't see "greatly increase your 24/7 energy consumption" the only consumtion would be keeping a couple of NiCad Cells trickle charged.

[John Rumm]

Depending on the type of lighting already installed, you may be able to use a conversion kit to power the existing lamp in a "non maintained"[1] way. These basically consist of a LED or Fluorescent driver combined with an inverter and a charger, plus a Li-Ion battery.

[1] Non maintained means they come on when the power fails, but you can't turn them on manually to use as regular lighting.

The advantage of that route is a more aesthetically pleasing install with no extra lamps.

However you can also get very small LED downlights that mount flush in a ceiling and are quite unobtrusive.

Powered from the light fitting makes more sense - it will then come on when the power to the light fails.

For example see:

Not really.

[Martin Brown]

It will roughly double your base load if you do every room...

At least for the classical ones you have a transformer dissipating a few watts for each unit and warm to the touch. When mains is on they trickle charge the cells and when mains goes off the transformer becomes part of an inverter generating a voltage to drive a fluorescent tube.

I don't know how well behaved the latest LED units are. They are also much more likely to be using SLA's. NiCads went out with the ark.

[GB]

16 rooms, so I can understand why you need so many interlinked detectors. There could be a fire in say the west wing, with you in the east wing sleeping right through it until the fire burnt itself out. It would be embarrassing explaining to the insurers why you hadn't called the fire brigade. :)

[alan_m]

I have two, one in the downstairs hallway and the other in the upstairs hallway. All other rooms lead off the hall and will get sufficient light when the doors to the rooms are open. My reasoning for position is that they will also light up the stairs. My LED versions have a green charging light which is bright enough to dimly illuminate the upstairs landing on the route to the toilet at night

On a non-maintained light the energy consumption will only be for the trickle charge of the battery and to illuminate the charging indicator.

[ARW]

rings a bell:-)

[ARW]

Emergency lighting should be on the local lighting circuit unless they are on 24/7 on their own circuit.

[SH]

Thats an interesting solution. I assume that:

(a) I can pass the battery and module through the existing cable hole in the plasterboard (underneath rose)

(b) is the on - off switch still operative during a powercut? that would extend power cut time cover so that the light does not simply stay on until the Li ion battery discharges completely?

(c) I have fibreglass insulation in the ceiling voids. Is that going to be an issue with the module and battery?

[SH]

and do they need a means of electrical isolation between the emergency light and light fitting or is simply opening the RCBo enough to test the emergency lights?

[John Rumm]

Looks like it.

The wiring diagram shows that the switched live is connected to the input of the unit and not in the output from the unit. So it might be the case that it only runs the inverter when the power fails AND the switch is on. However it does not actually say that.

They suggest it should be fixed to a surface, and that surface must not be combustible below 200 deg C.

[Bob Eager]

I have a single one, halfway down the stairs. It lights hall and landing, and also a totch repository!

It's wired into the detector circuit. If I see the light on and there isn't a power cut, I know that the detector circuit has tripped and needs attention.

[Bob Eager]

I have a green neon surround on the landing light switch. It is surprisingly bright.

[John J]

I know my way around our house in the dark. There's a torch kept near the consumer unit. While I don't disagree that emergency lights are handy you do sound a bit obsessive.

[ARW]

You can get self testing or infra red controlled emergency lights.

You never turn the whole lighting circuit off to test the emergency lights.

[Colin Bignell]

Alternatively, well prepared for the power cuts predicted for this winter.