Confusion about max wattage for light fitting?

[AP1990LTN]

Hello I hope you are well, I have a question regarding this light fitting (BELL 10361 Retro Vintage Half Lantern - Black, PIR, IP54) on the product data sheets it states the max lamp that can be fitted is 42W is that 42W total or equivalent it doesn't state? So would a 18W LED GLS be unsuitable to fit as the equivalent wattage is 100W? So in that case the max wattage lamp that I can fit is a 7W LED?

Light Fitting http://www.belllighting.co.uk/assets/img/products/10350_inst.pdf

Lamps http://www.belllighting.co.uk/lamps/LEDEnergySaverTechnology/DecorativeLED/LEDGLS/05119 http://www.belllighting.co.uk/lamps/LEDEnergySaverTechnology/DecorativeLED/LEDGLS/05628

Thank you for your time, Andy

 

[littlespark]

The wattage doesn’t matter, it’s the heat that is generated.
So an LED lamp, whatever it’s equivelant, will be fine.

might just look a bit too bright

 

[AP1990LTN]

Yeah I understand now, the 18W LED equivalent is 100W incandescence however the actual LED lamp will not draw more then 18W of actual energy so well under the maximum 42W

 

[DefyG]

You'd best check with the manufacturer as the wrong wattage lamp may invalidate any warranty irrespective of the heat generated!

 

[Lucien Nunes]

The main point of a 'maximum wattage' for the fitting was so that the fitting did not overheat. Therefore, as mentioned above, it is the actual circuit watts of the LED lamp, not the incandescent lamp equivalent, that must not exceed this figure. But there is a sneaky caveat, which is that if the ventilation inside the fitting is limited, there is a possibility that the LED lamp could overheat even while the fitting remains in-spec and safe, because LEDs are not as tolerant of high temperatures as incandescents. That is why incandescents are still specified for ovens etc. Therefore if the fitting is of a type that is designed to run hot at maximum rated wattage, such as a compact bulkhead, one should probably not go too near the maximum with an LED.

 

[AP1990LTN]

The main point of a 'maximum wattage' for the fitting was so that the fitting did not overheat. Therefore, as mentioned above, it is the actual circuit watts of the LED lamp, not the incandescent lamp equivalent, that must not exceed this figure. But there is a sneaky caveat, which is that if the ventilation inside the fitting is limited, there is a possibility that the LED lamp could overheat even while the fitting remains in-spec and safe, because LEDs are not as tolerant of high temperatures as incandescents. That is why incandescents are still specified for ovens etc. Therefore if the fitting is of a type that is designed to run hot at maximum rated wattage, such as a compact bulkhead, one should probably not go too near the maximum with an LED.

That explains it well, thanks so would you think that 18W is acceptable as while high for an LED is still below the limit.