80 3.8v High Power Led dangerous?

Hi, for a prototyping project i want to build a large light panel. 80 green HighPower LEDs from Sparkfun are selected. 750ma and 3.8v each.

I planned to use our 220AC Net supply to power four LED drivers.
But while planning i was wondering about the dangers of the led specs alone.

I am fairly new to electronics and have yet to fully incorporate deeper understanding of this relationship:

May I ask: When i put 80 of these led in four rows. each 20 led in row, 4 rows parallel. I would get 20 x 3.8V si 76V and 4 X 750 mA so 3.000 mA or 3A of current. Right?

That brought me to this question: is that now way over save power levels?

i thought that 30mA ++ are already dangerous since rcd are acting on that current? and i got 3 amps?! or / And that 50+DC is dangerous and life threatening...

how can i make it more secure? And what would you reccomend to drive the leds? Thanks a lot

A single 100watt COB LED could be easier than lots of seperate LEDs.
Also easier to cool (with a CPU cooler).
100watt mains powered LED drivers are common. Some can be PWM dimmed.
Leo..

I’m not sure where you think the danger is coming from so I’m not sure if my answer is helpful. Current is dangerous if it passing through your body. For sure, those levels of current would kill you if it was through your body, but it’s not, it’s through the LEDs. Current is also dangerous in a different way, if the wires it is passing through are not capable of carrying it they heat up, if they heat up enough there is the potential for fire.

As for the 30mA sensitivity of an RCD, that is to protect you against current from the mains going through your body and killing you. If you touch a live wire then the current through your body does not return via the neutral wire. The RDC detects this imbalance and switches off the power, hopefully in time to prevent serious injury to you.

May I ask: When i put 80 of these led in four rows. each 20 led in row, 4 rows parallel. I would get 20 x 3.8V si 76V and 4 X 750 mA so 3.000 mA or 3A of current. Right?

It is not as simple as that, what are you using as a driver?

A voltage of 75V in regulatory terms is higher than what is covered by the safety low voltage regulations. That is for things under 50V. A 75V power supply will be hard to find and require some skill making.

Hey,

thanks already.

Well kets focus on the power supply. We use these drivers

Four of them parallel and connect 20led each.
I read that save levels are 50v ac and 120v dc in germany.

Sadly we don't know the datasheet of the rcd in the cellar of the building.

But would that be ok?

https://m.reichelt.de/led-trafo-60-w-2-90-v-dc-dimmbar-mw-lcm-60-p138357.html

That should be fine.

I read that save levels are 50v ac and 120v dc in germany.

No. 120V can kill you (under the "right" conditions).

And, a constant-current power supply will put-out maximum voltage with no load (as it "tries" to push current through infinite resistance) so it might put-out more than 90V under "abnormal" conditions.

Sadly we don't know the datasheet of the rcd in the cellar of the building.

That's last resort safety protection after something has gone wrong. You should treat the LED power supply the same as you would 220V. The wiring and terminations should be insulated or inaccessible so nobody touches it, and don't drop it in the bathtub, etc.

Avion32:
Four of them parallel and connect 20 led each.

You mean to say, the primaries are in parallel and the outputs separately connect each to 10 LEDs in series to total about 60 V.

Avion32:
I read that save levels are 50v ac and 120v dc in Germany.

Basically irrelevant.

Avion32:
Sadly we don't know the datasheet of the RCD in the cellar of the building.

Doesn't matter. These will have no connection to ground.

!! (externe Spannung 0...10V DC, PWM)
Cant run 20 LEDS serial

knut_ny:
!! (externe Spannung 0…10V DC, PWM)

That is for dimming function.

http://www.mouser.com/ds/2/260/LCM-60-SPEC-806173.pdf