Fixture socket say only use led equivalent to 75watt incandescent

[AC\DC]

Fixture say either 75watt incandescent or led equivalent led wattage.
So looking around 8-11 watts for led…..
Why would a led 100 watt equivalent not work still going to be way under the incandescent wattage.

seems dump to me

 

[Besoeker3]

Dunno. UK fixture sockets are 13A. That's about 3kW.

 

[AC\DC]

If the lights good for 75 watts that should be the controlling factor. I would think.
If I want to use a led that uses 75 watts.
still same wattage use

 

[LarryFine]

Because that's what the label says.

 

[AC\DC]

Well I get that lol, but third fixture I saw that stated that.

 

[jaggedben]

I'd happily put a 100w equivalent LED bulb in there and argue my case with anyone. Bring it on.

 

[Besoeker3]

If the lights good for 75 watts that should be the controlling factor. I would think.
If I want to use a led that uses 75 watts.
still same wattage use

That would be a lot of light. The brights lights in my house are 15W and I use these for my wife's painting projects.

 

[LarryFine]

You would think the same for dimmers, too, but:

"This dimmer switch works with up to 150-Watt of dimmable LED/CFL or 600-Watt of incandescent/halogen."

 

[gar]

220512-2100 EDT

I will suggest that there are least two reasons to not allow the LED bulb's actual wattage to be considered the same as an incandescent from the perspective of real power input.

1. The physical operating temperature of an incandescent bulb can be much higher than an LED. The electronic components in an LED bulb have a much lower maximum operating temperature than an incandescent.

2. The IR heat generated in an LED bulb is of a much lower color temperature, and thus that excess heat has to be transferred out of a fixture by conduction mostly.

3. An incandescent bulb runs much hotter than an LED, and therefore a great deal of that excess heat is radiated from the bulb rather than having to be conducted away.

4. It is likely that on turn on of an LED the peak inrush current is even higher than that of a tungsten filament bulb on a relative basis. A tungsten filament bulb has a typical maximum peak inrush of about 10 times its steady state value. I suspect that some LED bulbs have an even greater ratio.
.

 

[James L]

It might not be about the wattage, it might be about the heat generated. The LED driver, particularly really close to the screw base, can be really hot

 

[AC\DC]

I understand that, if the led is listed for use in enclosed fixture than the fixture wattage should not matter

 

[James L]

I understand that, if the led is listed for use in enclosed fixture than the fixture wattage should not matter

I would agree with that.

 

[tthh]

Or...the instructions were written be someone who has no idea what they are really saying

 

[jaggedben]

It might not be about the wattage, it might be about the heat generated. The LED driver, particularly really close to the screw base, can be really hot

If an LED delivers the same lumens (that's what 'equivalent' is supposed to mean here) for roughly 8 times less watts, then it's generating less than 1/7th of the heat of an incandescent. This can be offset somewhat by the factors gar mentioned in his post (except inrush strikes me as irrelevant), but not by that much.

The people who labeled the fixture just didn't bother to study the difference. They tested and listed it for incandescent and then for CYA stated the equivalent LED and didn't bother testing for what LED wattage it can safely handle. Or tthh is right that whoever did the labeling was just incompetent.

 

[James L]

If an LED delivers the same lumens (that's what 'equivalent' is supposed to mean here) for roughly 8 times less watts, then it's generating less than 1/7th of the heat of an incandescent.

It's not the LED that makes the heat, it's the driver components. And they can get really hot.

You may be right as a whole, but it's possible they had a technical reason

 

[gadfly56]

That would be a lot of light. The brights lights in my house are 15W and I use these for my wife's painting projects.

My default preference in lighting levels is "surgical suite", but a 75 watt LED might be a tad excessive.

 

[texie]

My experience indicates that OPs rating question is due to the electronics getting to hot. I have a flush mount enclosed fixture with horizonal lamp sockets rated for 2 60 watt incandescent lamps. I use Phillips LED 60 watt equivalent lamps and they always have a much shorter life than I get in other fixtures.

 

[AC\DC]

My experience indicates that OPs rating question is due to the electronics getting to hot. I have a flush mount enclosed fixture with horizonal lamp sockets rated for 2 60 watt incandescent lamps. I use Phillips LED 60 watt equivalent lamps and they always have a much shorter life than I get in other fixtures.

Are your bulbs rated for enclosed fixture if not that could be why the short life span

My 75watt led was just for comparison.
I think a 75 watts is like a 400watt hps so quit a bit for a fixture in a small room.

 

[jaggedben]

It's not the LED that makes the heat, it's the driver components. And they can get really hot.

The bulb as a whole has a wattage rating about 1/8th of a incandescent. Whatever percentage of the watts are turned into heat are included in that wattage.

 

[tallgirl]

The bulb as a whole has a wattage rating about 1/8th of a incandescent. Whatever percentage of the watts are turned into heat are included in that wattage.

Yes, but the driver components have to be cooled by conduction into the base. Someone likely calculated the thermal conductivity, expected maximum ambient temperature, and then decided how hot they wanted it to get.