Powering the lights in a powercut...

[2cvbloke]

Ok, I had an idea today about how to keep my lights working during a powercut, and the idea is to wire up the lights so that they run through a UPS so when the power goes, the lights stay on...

I use energy saving bulbs in all my light fittings (5 lights total, excluding the Cellar, but that's on it's own circuit) so the 190w UPS I have spare would work for a couple of hours, going by how long it lasted when I last used it to power a normal 60w lightbulb in my cellar before I had a long enough extension cable, and as the UPS is pants when just having my computer stuff hooked up to it (screams it's little head off when my monitor comes on!!!) it's been sat around doing very little other than power the odd few dodgy looking devices to test them before plugging them into the mains...

I've attatched a basic wiring diagram of the idea so you can ponder over it or just scream "NOOOOOO!!! DON'T DO IT!!! IT'S TOO DANGEROUS!!!"...

 

[PoloMint]

Where are you planning on putting this? Can you wire directly into the UPS or does it need some sort of socket?

 

[PoloMint]

Wait a minute, are you just planning on cutting the lighting circuit and wiring this thing in?

If so, you might run into problems if your ligthing circuit is a ring (little ones aren't normally I believe). If it is a ring it would mean you would have: fuse box > UPS > all lights > fuse box instead of: fuse box > all lights > fuse box.

In a powercut with one end of the ring connected to the UPS and the other ending up back and the fuse box you might inadvertently end up trying to power the rest of your house, and street, backwards through your lighting ring. And if your UPS moans about your monitor think what it will say about that.

Of course I could be talking nonsense, and that might only be a potential problem if the lighting circuit is indeed a ring.

Anyway how often do you get a powercut?

 

[pgh13]

Don't think lighting circuits are usually wired as a ring, but to do what you are thinking of you'd have to patch in to where the lights are fed from the consumer unit which, although may not be unsafe, probably contravenes the regs and/or part 'P'. Having said that, though, I've thought about doing similar to feed my CH cct, but as Polomint said, power cuts aren't that common......Yet:-)

 

[Channel Hopper]

The UPS boxes here have a four way extension socket stuck on them, and so I would recommend getting a couple of standalone lamps that you can use in or near the computer room.

A PC UPS system is not big enough to run more than a couple of lights, on top of the PC, so dont start wiring up the unit to the reast of the house.

 

[2cvbloke]

A PC UPS system is not big enough to run more than a couple of lights, on top of the PC, so dont start wiring up the unit to the reast of the house.

It's not going to run my PC anymore (not that it ever did to be honest!!) as I have a 480W UPS to do that now (only £10 too )...

As for the lighting, it doesn't look like the lights have been wired up in a ring circuit (and neither have the sockets by the looks of things!!! ), as there's just one 5 amp cable leaving the box towards the ceiling, the other is direct to the Cellar light, which I'm not too fussed about running as it's just a damp mess down there (and today there's an inch of water on the floor, but that's something different...). But my understanding of how a basic ring would work is like this:

o-----------o
¦           ¦
¦           ¦
¦           ¦
{}----------o
¦
[][][] (fusebox)

¦ -- = Cable
o = light
{} = Junction box

Also, as there would only be a maximum of 5 Energy Saving lights in use it won't exceed the UPS's capabilities. Also, the UPS would be with the fusebox on a shelf next to it. I did think that fitting one of those 5amp round-pin lighting sockets and plug (as it's an IEC (Kettle type) plug & socket UPS, standard stuff from a computer parts supplier) would be a good idea incase someone mistook it for a standard 13amp socket, then have that going into the UPS, then the cable comes out of the UPS into the junction box and back into the lights, and when I move out I just rewire the junction box so that the lighting cable just goes straight through and my landlord's none the wiser...

As for powercuts, I'm getting a prepay meter fitted soon, and those things are a pain in the arse, especially when they cut out in the night (and as it's getting towards winter time that'll be earlier in the day) and I can't see what I'm doing or where I'm going, and in the past I've done myself a few injuries because of those damned meters, so I want to be safe and have some backup lighting than to stumble about in my house in the dark...

 

[Channel Hopper]

Four candles ?

 

[PoloMint]

In your ring diagram I think both ends connect back to the fuse box (in the diagram they seem to join before meeting the box).

Anyway if it isn't a ring, then your idea sounds like it might work.

I doubt what you are doing will meet building code, and as for connecting it all back up when you are finished, watch out if you are cutting the wire from the fuse box. I'm not sure about the UK (someone might be able to confirm) but in some countries all junctions and joins in cables must be exposed or accessible, so if you plan on just joining the wire with an inline junction and pushing it back in the wall behind the fuse box this would fail an inspection (should it ever actually be inspected).

Avoid adding junctions and sockets that you really don't need to. Also I wouldn't do it before you get your new meter, the guy fitting it might not like the look of the UPS box, oh, and don't kill yourself.

I know this sounds fun, but is it actually worth it?

BTW I'm not an electrician of any kind, and completely unqualified to advise on any of this.

 

[PoloMint]

Of course this assumes that the UPS unit itself doesn't draw more than 5A when charging. !

 

[Channel Hopper]

BTW I'm not an electrician of any kind, and completely unqualified to advise on any of this.

Is anyone ?!

 

[2cvbloke]

Of course this assumes that the UPS unit itself doesn't draw more than 5A when charging. !

That's what I've been wondering, but I have no means of finding out though...

Also, as I'm thinking of sitting the UPS next to the meter & fusebox the junction box I'd put in would be exposed and easily accessible...

 

[PoloMint]

That's what I've been wondering, but I have no means of finding out though... ...

Can't you discharge it then put a 5A fuse in it's plug and see if it charges or blows the fuse?

 

[Saturlight]

Sorry, but I use a torch.

 

[2cvbloke]

Can't you discharge it then put a 5A fuse in it's plug and see if it charges or blows the fuse?

I suppose I could, but I have no working 5amp fuses spare (they're either in use or already blown...), but I suppose as I have RCD switches instead of fuses in the fusebox it wouldn't be a problem if it did overload the circuit and tripped the switch...

 

[2cvbloke]

Sorry, but I use a torch.

That'd be ok, if you could find the damned thing in the dark!!!

 

[Saturlight]

Oh, yeah...LOL ;)

 

[2cvbloke]

Oh, yeah...LOL ;)

Then there's also the case of whether the batteries are dead or not...

 

[Topper]

I have RCD switches instead of fuses in the fusebox

Thats an interesting acronym could you enlighten me as to what it stands for?

My box has MCB's Micro Circuit Breakers

 

[Analoguesat]

RCD = residual current device (quick blow tripswitches)

 

[rolfw]

Residual Current Device http://www.aelgroup.co.uk/hb/hb040.htm

God I hate acronyms.