Submerged Socket in Lawn

[Kistelek]

After some advice please. Planning a chunk of work on my bungalow and one of the things we're planning to do is plant a permanent Christmas tree in the front garden that we'd like to illuminate at appropriate times of the year.

Having a cable trailing from the tree to the house ranges from not ideal to downright lethal because I'll forget it's there and trip and maim myself.

Does anyone know of a floor box type socket that can be set in the lawn, wired back to the house, that I can plug the lights or whatever into?

 

[flameport]

There are no 'floor' mounting sockets for outside use because they would fill with water.
Plenty of other outdoor sockets which could be mounted to a short post near to the tree.

 

[Kistelek]

There are no 'floor' mounting sockets for outside use because they would fill with water.
Plenty of other outdoor sockets which could be mounted to a short post near to the tree.

I did think that was the likely answer but thought I'd ask first before dismissing the idea. Thanks.

 

[JohnD]

Modern LED festive lamps last for an amazingly long time on batteries. I've used them outdoors with Lithium batts, which have an extra-long life, but alkalines will do if the battery box is easily accessible so you can change them during the six months of Christmas.

 

[ban-all-sheds]

There are no 'floor' mounting sockets for outside use because they would fill with water.

It's not beyond the wit of man to create a small chamber which stays dry in all but standing floodwater conditions, and the difficulty would vary according to soil type and local elevation (e.g. at the top of a hill on chalk = not too hard, at the bottom on clay = PITA), and in which for 10-11 months of the year you have the end of a buried cable coiled up with a waterproof connector, and in use you remove it from underground, but is even the minimum faff worth it? And would it be the best provision anyway?

Plenty of other outdoor sockets which could be mounted to a short post near to the tree.

Or a weatherproof enclosure.

Kistelek, you should think about the lighting you're likely to want. What are the chances it would be 230V? If you need to plug in a power supply, be it trailing or a wall-wart, you'll need more than just a socket to house it.

 

[FrodoOne]

After some advice please. Planning a chunk of work on my bungalow and one of the things we're planning to do is plant a permanent Christmas tree in the front garden that we'd like to illuminate at appropriate times of the year.

Having a cable trailing from the tree to the house ranges from not ideal to downright lethal because I'll forget it's there and trip and maim myself.

Does anyone know of a floor box type socket that can be set in the lawn, wired back to the house, that I can plug the lights or whatever into?

Since the festive lighting is likely to be supplied with the "Extra Low Voltage" of 12v or so, why not just run an "Extra Low Voltage" pair of conductors buried in the garden from the house (or garage) to a suitable connection box mounted on a "pole" adjacent to the tree concerned and connected to suitable terminals at both ends.

In this way, come Christmas, you could supply the lights from the house (or garage) with the required extra low voltage output 230 V transformer (and any control equipment etc.) would be under cover, in the house (or garage).

 

[ban-all-sheds]

In this way, come Christmas, you could supply the lights from the house (or garage) with the required extra low voltage

And possibly radiate significant EMI from that long cable....

 

[winston1]

And possibly radiate significant EMI from that long cable....

Why should a 12v or whatever 50Hz cable radiate EMI any more than a 240v 50Hz cable?

 

[JohnW2]

Why should a 12v or whatever 50Hz cable radiate EMI any more than a 240v 50Hz cable?

Twenty times the current for the same load power?

However, as you are always reminding us, it is not necessarily 50Hz, nor necessarily anything remotely resembling a sine wave. Even the "DC (eff)" PSUs that berrnard so often mentions have a wide spectrum of potential radiation.

Kind Regards, John

 

[winston1]

Twenty times the current for the same load power?

However, as you are always reminding us, it is not necessarily 50Hz, nor necessarily anything remotely resembling a sine wave. Even the "DC (eff)" PSUs that berrnard so often mentions have a wide spectrum of potential radiation.

Kind Regards, John

I was not suggesting using anything other than a transformer. Transformers operate at 50Hz sine wave.

 

[JohnW2]

I was not suggesting using anything other than a transformer. Transformers operate at 50Hz sine wave.

I know you weren't, but we haven't got a clue as to what voltage-changing device (if any) the OP might have - if it came with a set of outdoor lights, it is very unlikely to be a wirewound transformer.

In any event, as I said, even if it is ELV, and was run from a wirewound transformer, the current for a given load power would be 20 times higher with 12V than with 240V and radiation (from a conductor very very much shorter than a wavelength) is broadly proportional to current - hence the answer to the question you posed.

Kind Regards, John

 

[winston1]

In any event, as I said, even if it is ELV, and was run from a wirewound transformer, the current for a given load power would be 20 times higher with 12V than with 240V and radiation (from a conductor very very much shorter than a wavelength) is broadly proportional to current - hence the answer to the question you posed.

Kind Regards, John

But there would no EMI from a 50Hz sine wave and 20 times zero is still zero. Of course if the cable was buried that also would attenuate any EMI.

 

[JohnW2]

But there would no EMI from a 50Hz sine wave and 20 times zero is still zero.

Essentially true. However, getting back into context, as I said, the main point is that it is exceedingly unlikely that a set of ELV outdoor lights would come with a source of 50Hz sine wave ELV - so when it was suggested that distributing the power at ELV might create EMI, I feel sure that the person who said that was thinking of what the OP would be likely to have (i.e. almost certainly something other than a wirewound transformer).

Kind Regards, John

 

[bernardgreen]

Of course if the cable was buried that also would attenuate any EMI.

Very little attenuation unless very deep.

The leads wrapped around the Christmas tree would be radiating RFI if supplied directly from an SMPS

If the SMPS is designed to work with the lamps connected directly to it ( lead length 300mm ) then it may not work correctly if there is a long lead between it and the load. This is due to the additional capacitances of the lead ( conductor to conductor and conductors to ground ) affecting the voltage stabilising function in the SMPS.

A wire wound transformer is the most reliable way to supply ELV to decorative lighting.

 

[ban-all-sheds]

I was not suggesting using anything other than a transformer.

You hadn't suggested the use of anything.

But feel free to go and research off-the-shelf LED tree light sets and report back on how many are supplied with WW transformers rather than SMPSUs. It would be good to know just how useful this contribution actually was:

Why should a 12v or whatever 50Hz cable radiate EMI any more than a 240v 50Hz cable?