Re: 9W LED inrush current

On 10/3/2024 1:46 AM, Martin Brown wrote:

For lighting *installations* (i.e., not individual lamps), I think they
use 100x the steady state current as an upper figure.  This is intended
to cover model and manufacturer variations.
>
With multiple lamps on a branch circuit (or whatever is driving them),
this can add up pretty quickly.
>

Why do you need to know?

>
<https://adlt.com.au/resources/led-inrush-currents/>

 Thanks for the link - that seems definitive and on high end units too.
 I had perhaps naively assumed that they would put a small inductor in series with the thing to limit worst case inrush current. It is only for a very very short time though ~100A for <1ms which real fuses won't even see and most domestic circuit breakers probably won't either.

"Best Practices" (for industrial-scale installations) is to put a
"smart" driver *in* the lamp and just run "unswitched" (excepting
for circuit breaker) mains voltage to the fixture(s).   Then,
use smart controls to slightly stagger (like one mains cycle)
the startup of multiple lamps.
I have one of these mounted in our garage:
    <https://protolight.com/files/2019/05/Lumenbeam-LBX-cc-hex-2.png>
(may not be the correct model; I'm too lazy to walk out there and
take a look  :<  The yoke in the picture seems too large -- the lamp
is about 14" in diameter)  It dissipates 100W -- intended to light the
EXTERIOR of large *buildings* dramatically.   (I use it as a way
to inform the driver of a vehicle entering/exiting the garage of
a hazzard or caution needed in his actions -- like "you're too close
to the side of the space" or "you are about to run over something")
It is controlled by a wonky serial protocol layered on EIA232.
The drivers inside the lamp ("luminaire") try to play nice with
the mains (multiple discrete emitters involved -- RGBW).  It's up
to the controller that is talking to them to coordinate their
loads.

By comparison the arc caused by a filament spotlamp in the kitchen going pop bang almost always exceeded the max trip current by some margin.
 My lighting circuits are now almost exclusively LED based and I have never seen any signs of trips. Although I never put all the lights on at once and then done a system mains power off/on at the breaker box.

Most of our lighting circuits are 6-10 lamps (I like/need? a LOT of
light and grumble when SWMBO is always turning their intensity down).
We've not had any problems -- but, I assume the dimmer controls
("for use with LED") have taken some steps in this regard, along
with manufacturers of the actual lamps (no one would be using them
if they had to reset a breaker each time they flipped a switch "on"!)

That is about the only time that this 100A surge risk becomes a problem. One of my switched loads is 10x 7W LED candle lamps and has never caused a problem. Back when it was 10x 40w incandescents it was a heat source!

Again, "I line/need lots of light"  :>  My bathroom was like a
sauna -- 8x60W -- with incandescents!  A dimmer made it tolerable
for normal use vs. "crank it up for a clean shave!"  :<