Constant current LED driver pairing with LEDs

[phatboy]

Good evening all,

I bought from a lighting designer a few circuits of fittings with drivers. According to the instructions, they are to be wired in series using the provided constant current driver

Each lamp is 2.9v
The driver is 72v
The circuits each contain between 4 - 7 lamps, and each has a driver.

The drivers have some dip switches to reduce the voltage, but only as far as 36v.

Should I be reducing the voltage as low as it will go? 2.9v x4 is still way below 36v, but I think the current is more important here a and the voltage may not be particularly important?

This is the driver: https://www.ecopacpower.co.uk/led-drivers/constant-current-led-drivers/eled-40p-c300-1400t-series

Any guidance gratefully received.

 

[flameport]

The switches must be set for the correct current output, which is what the LEDs are designed for, 350mA and 700mA are common values but there are others.
Voltage doesn't matter, as it will be automatically varied to achieve the current. More LEDs connected = higher voltage required.

The only real consideration for voltage is that with higher current, the maximum voltage will be limited to avoid overloading the power supply, and that will also limit the number of LEDs that can be connected to it. If you connect too many LEDs the voltage required to drive them will be too high and none of them will work.

Setting to the lowest voltage is absolutely the wrong thing to do, as that will result in the highest current output, and is likely to destroy the LEDs.

 

[phatboy]

The switches must be set for the correct current output, which is what the LEDs are designed for, 350mA and 700mA are common values but there are others.
Voltage doesn't matter, as it will be automatically varied to achieve the current. More LEDs connected = higher voltage required.

The only real consideration for voltage is that with higher current, the maximum voltage will be limited to avoid overloading the power supply, and that will also limit the number of LEDs that can be connected to it. If you connect too many LEDs the voltage required to drive them will be too high and none of them will work.

Setting to the lowest voltage is absolutely the wrong thing to do, as that will result in the highest current output, and is likely to destroy the LEDs.

Thanks, this is very useful! I knew I was unsure, hence asking.

The lamps are 700maA/ 3v (This is only written on the unit, not the boxes or data sheet so I had to go and re-check).

I am not sure how to calculate the load to be honest, adding the mA values goes off the scale of the driver, but I don't know what voltage it is based at, presumably the full 72v?

My circuits are 6 lamps, 5 lamps & 4 lamps, and this is the driver spec.:

Many thanks
Tim

 

[flameport]

Just set the switches to 0.7A, wire all of the LEDs in series. The driver will do the rest.
It will work from a single LED upwards with no further adjustments required.
With one LED connected the output voltage will be about 3V. With more, the voltage will increase automatically.

They will be about 2 watts each (current x LED voltage), so even with 6 connected it's well within the 40W maximum of the driver.

This is the wiring arrangement required:

 

[bernardgreen]

Running LED elements on a current lower than their rated current will prolong the life of the elements.
Very often the LED elements can be run on a lower current while still producing enough light

I would advise using 550 mA current as a test to see if the LED elements are bright enough with a life extending lower current

 

[phatboy]

Just set the switches to 0.7A, wire all of the LEDs in series. The driver will do the rest.
It will work from a single LED upwards with no further adjustments required.
With one LED connected the output voltage will be about 3V. With more, the voltage will increase automatically.

They will be about 2 watts each (current x LED voltage), so even with 6 connected it's well within the 40W maximum of the driver.

This is the wiring arrangement required:
View attachment 337018

Thank you for the fantastic advice, I shall do just that

 

[phatboy]

Running LED elements on a current lower than their rated current will prolong the life of the elements.
Very often the LED elements can be run on a lower current while still producing enough light

I would advise using 550 mA current as a test to see if the LED elements are bright enough with a life extending lower current

Thank you, I will try this mode, and what Flameport suggested