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I want to build a lamp socket base out of wood. In general I'd have a total of three lamps sockets hanging from it, which I'd feed through drill holes and would wire together in a hollowed out part of the wood.

 _________________
|_________________|  <- wooden board/slab
   |     |     |
   |     |     |
   O     O     O  <-lamp sockets

This means electrics and flammable material together.Naturally, this brings up some concerns as I don't want to burn down my house. Is this in general a bad idea, or how can I achieve this in a safe way?

Additional info View from top on hollowed out fixture with cable canal:

    cable feeds from bulbs     
        ↓      ↓       ↓
     ____________________
    |                    |
    |   O------O------O  | 
    |____________________|
               ↑      
         wiring all together 
  • Where are you on this planet? – ThreePhaseEel Dec 3 '19 at 12:39
  • Switzerland, we have 230V power outlets – Herr Derb Dec 3 '19 at 14:03
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    If it makes you feel any better, your walls are filled with electricity and flammable materials. – JPhi1618 Dec 3 '19 at 15:42
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    People have been making table lamps out of turned wood for as long as the Edison light bulb has been manufactured. I wouldn't worry about a thing. – FreeMan Dec 3 '19 at 19:38
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I know you've seen LED replacement "bulbs" that screw in, and you know those fail. What is failing isn't the LED. It's the conversion power supply which converts 230V to 3V for the LEDs, which tend to be built very cheaply. You could fix them, but it's not worth it. Don't let that scare you away from LED tech. The actual LED emitters proper have an extremely long service life. They will not burn out, probably in our lifetimes.

So anytime you're homebrewing a lamp, the right answer is to use LEDs because LEDs use low-voltage and run cool. There's a quasi-standard for projects like yours, to use 12 volts DC -- the LEDs won't run directly on that, but there are lots of ways to buy 12 volt LED modules that simply contain three LEDs and a resistor. The resistor will last as long as the LEDs.

To power that, you use a common, commercial off the shelf 230V-12V "wall wart" type power supply, which is listed by the relevant safety agencies - BSI, TUV, UL, whoever you use. (CE is pretty worthless when dealing with China). That means you are never touching mains voltage. An electrical short could still cause a fire, but 99% of such fire-starters are arcing faults across open connections, and 12V doesn't really like to arc. All the "failable" electronics are in the wall-wart, all the rest is wires, LEDs and resistors. The wall-wart will be what fails, just swap it.

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This will probably be fine. Electrics and wood are not a good combination if the electrics get hot. Electrics get hot if there is a lot of current flowing through a poor joint.

If you want to fit three 500W incandescent lamps, and you are using a 120V supply, then you would need 12.5 amps; and this is a lot of current.

If you are using 220V mains it would only be 7A, which is quite a bit better.

Realistically however, you probably don't want anything more than three 200W equivalent LED lamps (which are 23W each). Even with 120V, that is only about 0.6A.

The important point is that heating in junctions and wires is proportional to the square of the current. Just over half an amp is not a particular problem (but it's always a good idea to make your joints as cleanly as possible).


There are two additional points:

Firstly, if you are relying on the low current consumption for safety, you need to ensure that nobody (who doesn't understand the construction) can swap in a high current lamp. If you use a fitting with the LED built in, this is assured.

Secondly, whether this is legal or not will depend on where you live.

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    I would like to add that if you use a thicker gauge wire it will make the heating of the wires less because of the lowered resistance, making it even safer to run the cable – JIMMYPlay Dec 3 '19 at 14:12
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I'm a little concerned that the existing answers are based on an assumption that you are familiar with wiring codes and good electrical wiring practices. There is nothing incorrect in those answers, but there are many considerations left out that could affect safety. To get a reliable answer, you should really include the design detail. Even with low voltage LED lighting, you can create problems for yourself. A few considerations that come to mind:

  • This is a ceiling fixture. If you use a wall wart to power LEDs, how will you connect it to mains power? You could stick an outlet in the ceiling, but how will you secure the wall wart to it? How will you ensure that the weight of the fixture is never pulling on the wall wart or its wire, including during installation or servicing?
  • Three lamps means tapping power for each one. How and where will you make those connections? How will you keep the connections from getting mechanically stressed? How will you ensure good electrical joints, and connection insulation to avoid shorting?
  • Do you know what gauge wire you will need to carry the maximum current there could be if someone inadvertently puts high wattage incandescent bulbs in the sockets in the future?
  • How will you mechanically support each lamp? If each lamp will be just a socket, bulb, and featherweight shade, the wire, itself, may be enough to support it if you use appropriate wire, and mechanically secure both ends so the weight of the lamp isn't pulling on the electrical connections. If the lamps have heavy glass shades, hanging them only by the wire is a bad idea.

Your fixture will generally have less risk if you're using LEDs, but it will still take good design and wiring principles for it to be safe.

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  • It's definitely nothing I do everyday, but I generally come from the technical side myself. Yes, it's going to be a ceiling fixture (hollowed out from the top where needed). I'll have textile cables fed through the fixture on which the light bulb will hang, and which I will secure inside the fixture. So this should be fine. The cables inside the fixture, I intend to connect with wire nuts (not sure if this is the right term) This will be the only part with no insulation on the wires. – Herr Derb Dec 4 '19 at 7:25
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You mention two very different things:

I want to build a lamp socket out of wood.

This implies the base of the light bulb is inside the wood - i.e., a hole in the wood with the socket embedded in it. With that I would be very concerned, even with LEDs, about heat.

I'd have a total of three lamps hanging from it

On the other hand, if you have light bulbs hanging from the wood, even just a few inches away, the risk is much less as the heat dissipates into the air instead of directly into the wood.

As mentioned elsewhere, if you use some sort of LED device that is not a screw/plug-in bulb/socket then you can easily avoid the problem of someone (10 years from now when the LED driver wears out) screwing in a 60-Watt incandescent bulb they found lying around and starting a fire.

If you do use a non-bulb LED device, try to find a high-quality device. DLC is a key certification to look for. On the other extreme, make sure at a minimum that the devices are UL listed (or similar, not "CE" which effectively means nothing at all or "FCC" which has to do with radio frequency interference but tells you nothing about the quality & safety of the device). A well-known brand and a long warranty are not guarantees but are good indicators of quality.

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