Domestic mains LED lightbulbs need to be waterproof?

[treez]

Hello,
I understand that domestic mains LED lightbulbs need to be completely sealed, or else condensation could get into the circuitry and short it out.
When these lightbulbs are being manufactured, do some of them have to go to production tests whereby the entire led lightbulb is immersed into water, the bulb is then dryed off and then plugged into the mains.......if it fails, then there is a problem with the sealing.

I mean, is this kind of test done?

 

[Audioguru]

Pure water is an insulator. Salt water or water with acid conducts electricity. I don't know about water with alkaline, it might conduct.
I think condensation is pure water so it would not short the light out.

Compact fluorescent light bulbs do not have their electronics sealed. They have vent holes for cooling.

 

[treez]

Compact fluorescent light bulbs do not have their electronics sealed. They have vent holes for cooling.

...thanks, I thought this was illegal though, because of the live mains inside?

 

[godfreyl]

There's live mains inside everything from light fittings and light switches to vacuum cleaners, toasters, hair dryers, and TV sets, but none of those are required to be waterproof.

 

[treez]

ok, so why don't they put vent holes into mains led lightbulbs, which have internal switch mode drivers?


**broken link removed**

...has no vent holes, even though it could benefit from them

 

[Audioguru]

LED lights have heatsinks with exposed fins that cool them. No need for holes. 7W is not much heat.
My switch mode AC-DC adapters have a pretty high output current, are small, have no holes and they do not even get warm.

 

[treez]

Yes I agree, the leds are mounted on a alu heatsink, and that heatsink opens to the exterior.
However, due to the severely large amounts of energy that it takes to make aluminium from bauxite, they are doing away with alu heatsinks in lighting applications now....instead they are having lots of low power leds on wide area pcbs, and just relying on the pcb copper to cool the leds, and the hot air from the leds rises up out of air vents. This is the way its being done in the latest led bulbs.

Also, even when exterior-opening-alu-heatsinks are used, they only cool the leds, the offline flybacks switching fet wouldn't likely be stuck to that heatsink (even via an insulative spacer)..............so air vents would be useful to allow the offline switcher's components to cool off..do you agree?