Can LED filament light bulbs be deadly?

[Oldie]

These light bulbs have an extremely thin glass. And even if the glass is broken they still work - see photos. Does anyone know how much voltage is there when they are switched on? If much it could be a death trap for careless people and children. 

[bankruatsteve]

I would be more concerned about the broken glass than the LED.

[tonray]

Why would anyone plug in a fixture with a broken light bulb ? Granted Light Bulbs do occasionally break...but that's when you drop them on the floor or hit them with something accidentally. Should be ample time to remove the broken bulb (after turning fixture off and replace it. BTW...wouldn't the same danger apply to a fixture without a light bulb installed ?

[Damual Travesty]

a broken outer glass. A definite safety hazard.  Replace it.

[carlyai]

I haven't actually seen these LED lights but they must have some electronics inside the screw base that controls the LEDS. I'd guess they are pretty safe, but you still have 220V applied and that would be the dangerous part.

[maxpower]

With enclosed LED filaments there is no need for safety isolation which means most of these lamps will have dangerous voltages at filament connections.

 

[carlyai]

8 minutes ago, maxpower said:

With enclosed LED filaments there is no need for safety isolation which means most of these lamps will have dangerous voltages at filament connections.

 

Do you mean there is no electronics an the LEDs works straight of 220 V? 

Just a clarifying question from me. ????

[maxpower]

21 minutes ago, carlyai said:

Do you mean there is no electronics an the LEDs works straight of 220 V? 

Just a clarifying question from me. ????

A common LED filament lamp circuit shown below shows the lack of isolation. Electronics are quite capable of working with mains voltages.

 

[Oldie]

14 minutes ago, maxpower said:

A common LED filament lamp circuit shown below shows the lack of isolation. Electronics are quite capable of working with mains voltages.

 

I googled a lot but couldn't find a clear answer. Now I watched some videos on YouTube where they dismantled such lamps and was surprised. It is exactly as you say. I thought these LED lamps are low voltage but this is not the case. Even if such broken lamps are switched off they pose a danger if the phases are not switched correctly. And also the not filament lamps with the white plastic cover are not low voltage. If the cap falls of and you touch the metal next to an LED connection you will have the same problem. For sure no lamps in areas where for instance kids can reach them. And I myself will be more careful too. 

[Yellowtail]

As long as you don't touch it you should be fine...

[OneMoreFarang]

The LEDs use only a few volts (like 3V per LED) and that is no problem.

But unfortunately it seems some of those are not produced without any safety in mind so if the glass is broken you might be able to touch something which you shouldn't touch.

 

[sometimewoodworker]

8 minutes ago, OneMoreFarang said:

The LEDs use only a few volts (like 3V per LED) and that is no problem.

Once you have enough, those lights are using lots, the voltage needed can quickly build up so 180v led PSUs are common. This means that you can get a nasty sting of them, though the current is usually very low so not being very dangerous. 
The other problem is that you may have a driver that references to mains so getting an even nastier sting.

 

For understanding check out BigClive on YouTube you will find more LED drivers analysis than you can get through in a couple of months 

[Oldie]

24 minutes ago, OneMoreFarang said:

The LEDs use only a few volts (like 3V per LED) and that is no problem.

But unfortunately it seems some of those are not produced without any safety in mind so if the glass is broken you might be able to touch something which you shouldn't touch.

 

The glass is extremely thin. I never saw such a thin glass. You can break it if you hit the lamp by accident with your hand. Also the metal contacts are not covered. These lamps should not be allowed to be on the market like this. In the meantime they produce lamps where the glass does not break so easily. But you have to find them... 

[jastheace]

bin it.

why take a chance.

knowing how some properties electrics are wired up in LOS, i always turned the main switch off when changing bulbs etc... i have experienced outlets still live when turned off at the local switch.

[KhunBENQ]

1 hour ago, OneMoreFarang said:

if the glass is broken you might be able to touch something which you shouldn't touch.

And no different to old fashioned bulbs.

Even though the filament (glow wire) will burn in an instant, the connecting wires are still connected to AC.

The difference of the described LED things seem to be the thin glass that breaks easier?

[sometimewoodworker]

19 minutes ago, KhunBENQ said:

And no different to old fashioned bulbs.

Even though the filament (glow wire) will burn in an instant, the connecting wires are still connected to AC.

The difference of the described LED things seem to be the thin glass that breaks easier?

The reason for the thin glass is that it has no need to be gas tight so can be as thin/light as possible.

[OneMoreFarang]

11 minutes ago, KhunBENQ said:

And no different to old fashioned bulbs.

Even though the filament (glow wire) will burn in an instant, the connecting wires are still connected to AC.

The difference of the described LED things seem to be the thin glass that breaks easier?

Normally the voltage on the LEDs is very low, you wouldn't even feel it. The voltage is lower than halogen bulbs which are used in many places and which people don't fear - because of the low voltage.

The problem with the LED bulbs like shown above is that the low voltage for the LEDs is only a centimeter away from mains 220V. And in low quality bulbs there will likely be no decent isolation.

[Oldie]

1 hour ago, OneMoreFarang said:

Normally the voltage on the LEDs is very low, you wouldn't even feel it. The voltage is lower than halogen bulbs which are used in many places and which people don't fear - because of the low voltage.

The problem with the LED bulbs like shown above is that the low voltage for the LEDs is only a centimeter away from mains 220V. And in low quality bulbs there will likely be no decent isolation.

What I learned from YouTube is that they are not low voltage. At THIS lamp are at least 110 Volt at each LED string. And depending how the phases are you might get fully connected to the main electricity. And even if the phases are correct you will not enjoy touching the wires. In respect of the glass - it is less than half a millimeter thick. 

[Oldie]

2 hours ago, jastheace said:

bin it.

why take a chance.

knowing how some properties electrics are wired up in LOS, i always turned the main switch off when changing bulbs etc... i have experienced outlets still live when turned off at the local switch.

This is a good idea to switch the main switch off. Often the phases are not correct. At every wall socket I have marked where the live wire is and at everything what is plugged in there I checked if it is plugged in a way so that the phases are correct. There is for instance not a single power strip that is not plugged in correctly. I check this. Everything else might be deadly. 

[sometimewoodworker]

2 hours ago, OneMoreFarang said:

Normally the voltage on the LEDs is very low, you wouldn't even feel it.

That depends on the LED, the number of them and how they are connected. While an individual one may need a low voltage depending upon design once they are in series rather than parallel you will have some seriously high voltages from the driver.

this is just one tear down and at about 7 minutes in you will see that the driver is putting out 150v

 

 

Edited September 13, 2020 by sometimewoodworker

[OneMoreFarang]

9 minutes ago, sometimewoodworker said:

That depends on the LED, the number of them and how they are connected. While an individual one may need a low voltage depending upon design once they are in series rather than parallel you will have some seriously high voltages from the driver.

this is just one tear down and at about 7 minutes in you will see that the driver is putting out 150v

Thanks for the clarification. I was referring to the bulb in the picture and not to high power LEDs.

[sometimewoodworker]

8 hours ago, OneMoreFarang said:

Thanks for the clarification. I was referring to the bulb in the picture and not to high power LEDs.

The light in the OPs post uses multiple LEDs.

 

The video is an example of the voltage produced to run 1 particular multi LED light and that it was a mains referenced driver.

 

go through BigClive’s YouTube history and you will find several string filament drivers analysed they do NOT use very low voltage drivers but ones similar to the video I posted.

[OneMoreFarang]

30 minutes ago, sometimewoodworker said:

The light in the OPs post uses multiple LEDs.

 

The video is an example of the voltage produced to run 1 particular multi LED light and that it was a mains referenced driver.

 

go through BigClive’s YouTube history and you will find several string filament drivers analysed they do NOT use very low voltage drivers but ones similar to the video I posted.

Thanks, I will educate myself. I am more used to these LEDs... ???? 

 

[sometimewoodworker]

10 minutes ago, OneMoreFarang said:

Thanks, I will educate myself. I am more used to these LEDs... ???? 

 

The principal is exactly the same, wire them in parallel, 3v supply
wire them in series = number of series x 3v 

the light shown in the video has 50 paired LEDs wired in series giving 100 in sets of 2 = 50 x 3v or 150v required 

[maxpower]

2 hours ago, sometimewoodworker said:

The principal is exactly the same, wire them in parallel, 3v supply
wire them in series = number of series x 3v 

the light shown in the video has 50 paired LEDs wired in series giving 100 in sets of 2 = 50 x 3v or 150v required 

Its important to mention current limiting when driving LED's because once the forward voltage is passed they will start to grab current to the point of self destruction. Forward voltage varies with type and color, 3V would be about average in the range.

Example - Single red LED off the Shenzhen market no spec sheet available.

1.8V 2mA (decent glow)

2.2V 30mA (max brightness)

3V 65mA

This is less of a problem with long series strings of LED's driven by constant voltage as small variations are absorbed by the string.