Wall wart in a box

[The Medway Handyman]

Already had some advice from my friendly neighbourhood sparky Adam about this, but wanted some more ideas.

Need to put some low voltage (12v) lights in a deck. 10 lights, each with 3 LED's.

Lights and manifold/junction are IP66, wall wart needs to be inside though.

Easiest wiring option is a disused security light. Only other option would be a right mission.

So, I'm thinking. I could run the cable from the unused light into an IP66 box like this

& plug in the wall wart.

Only question - do you think the wall wart might overheat?

[Adam Aglionby]

As long as it under 12W, a wall-wart-in-a-box :

[Tim W]

The Medway Handyman wibbled on Sunday 25 October 2009 17:29

Overheating: I would think it'll be OK in a box like that, unless, perhaps, the box in in full sun. There's quite a bit of space to air cool the wart via convection and plenty of surface area to lose the heat through.

Can you not drill a tiny hole right through the wall and extend the extra low voltage flex inside to meet the wall wart at a convenient socket?

Or is making use of the security light power feed the only way?

The only tricky bit AFAICS is putting a 13A socket on the end of the lighting circuit. People normally use 2A or 5A sockets for differentiation purposes. That would be shafted if the wall-warts plug is built in though.

The one thing that could go wrong is that someone down the line thinks: "Hmm

13A socket, I'll run me welder off that...". Clear labelling as to the circuit origin would be a must (ie: "This is fed by downstairs lights breaker, max load 1A" or something...).

Wait for some more informed opinions...

[The Medway Handyman]

'm confused. How would that help? It doesn't have an IP rating.

[The Medway Handyman]

Not the only way. I could do as you suggest, but due to the layout of the house I'd have to run a cable under the bathroom floor.

It is one of theose 'fat plug' type wall warts e.g the plug & PSU are one unit. Like a Nokia charger.

Good point - thanks.

[Tim W]

The Medway Handyman wibbled on Sunday 25 October 2009 21:26

I take it your proposed route would be up the wall to the ceiling level, hence the bathroom?

Can you not go left or right and hit another room? Not intending to doubt you, but thinking more of the occupant (including future ones) - a SELV cable at 12V or whatever doing weird things is a lot less likely to turn into an "issue" down the line.

What about diving in the corner of a window frame (a Sky dish installer favourite) - sorry hard to comment without knowing the house in question.

The other thing I think would be worth mentioning, if you do go down this route: I would regard it as essential that that circuit is backed by an RCD - is the security light feed already covered by one?

Sooner or later, labels, or not, someone is going to try plugging a radio/lawnmower or something else into this for use outside. And for those sort of loads, they'll probably get away with it without tripping the lighting breaker.

The risk is of course very tiny, but you probably wouldn't want to be associated with it...

Cheers

Tim

[The Medway Handyman]

Sorry, should have made it clear, old house, bathroom on ground floor, nothing above. Due to large slope bathroom floor is 3' above deck level.

There isn't anything left of right - only the neighbours bathroom :-)

That would go into the bathroom. Hole isn't the problem, I have extra long bits & a Mak SDS.

Don't know, I'll check.

There is a proper IP66 socket on the wall a few feet away, but a wall wart is too big to fit under the flap.

No, I wouldn't - hence the question :-)

[Tim W]

The Medway Handyman wibbled on Sunday 25 October 2009 22:21

[Tim W]

The Medway Handyman wibbled on Sunday 25 October 2009 22:21

The up to the soffit, though the loft trick? Down the corner of a bedroom wall in a neat bit of D-Line trunking.

Oh - in that case, use the box you mentioned and plug the little extension lead plug into the IP66 socket. Technically you're not even touching the fixed wiring then. User can unplug the lead if the need the socket for the lawnmower. It's not unneat either. Sorry - maybe I missed the bit about the IP66 socket.

[ARWadsworth]

Unless the wallmart is anything special you could repace it with a transformer and a lightswitch in the IP66 box.

The wallmart should tell you on its label what voltage/power transformer to replace it with.

Adam

[The Medway Handyman]

Genius! Why didn't I think of that?

[ARWadsworth]

LED lights, so it may be a constant current or constant voltage transformer.

Usually the constant voltage is the preferred option.

Adam

[Adam Aglionby]

Did try and point you in that direction Dave but it confused you....

As it happens though that range *was* IP rated, must be another one that comes potted with tails.

By the way you say 12V and LED, guess you really want 12V D.C. regulated, not an unregulated supply which would shorten life of LEDs considerably.

Previously linked PSU ticks that box but not the IP rated one but as suggested perhaps incorporation into a IP rated enclosure.

Most wall warts will have a non resetting thermal fuse which means in extreme overheat it will fail , but fail safe.

Cheers Adam

[The Medway Handyman]

I am a bear of very little brain sometimes...

Dunno, I'll have to check.

That would be easier.

Useful to know - thanks.

[Owain]

Just found this while looking at other stuff

Four channel DC 12V - 800mA outputs # AC 100 to 240V input - DC 12V output switched mode power supply # Supplied with five cable grip pass-through IP66 rated cable glands # Adjustable output voltage DC12 to 13.8V for long cable runs # Wall mountable IP66 enclosure

Similar probably available elsewhere for less.

Owain

[The Medway Handyman]

Cheers, alas twice the price of the lights :-(