We are having some trouble with our Lumen lights and would like suggestions on how to fix them.
We had an existing system using 4 stock daisy-chained lights and wanted to increase the number to 7. We already had a set of quad chained Revision 2 Lumen lights from around 3 years ago and added a single and a double set of new lights in line with our existing ones.
The daisy-chained lights were installed as show below:
(Enclosure)-(New Lumen 2x)-(Old Lumen 4x)-(New Lumen 1x)
As suggested in other posts on this forum we moved from 12V to 48V to accommodate for the higher current draw of more lights.
We did not test the new lights before adding them to our system.
In this configuration we noticed an issue where the first new lumen light (connected directly to the enclosure) flickers and typically does not get anywhere near the brightness of the other lights. This started happening before we did any water tests with the new light assembly.
The malfunctioning light is one we did not open to daisy-chain the internal connections.
The issue is odd as all downstream lights always work however the malfunctioning light sometimes ( <5%) will begin to work correctly. The light functioning seems to coincide with us changing the brightness of all the lights to another PWM value. When it begins working it appears to stay functional until we change the PWM signal again.
Thanks for your help, please let me know what other information you need to help address this odd behaviour.
Hi @offshoreRyan -
From the sound of it, that first light in your chain could have a bad connection? Opening it up to verify no moisture is present, and the wires are secure in their press-down terminals would be a good first step - share pictures!
Hi Tony,
I’ll open it up and share pics when I’m back in the office!
I would have thought a bad connection would cause downstream lights to also malfunction?
And the light in question began showing flickering symptoms as soon as we wired it, well before being exposed to water. Is it possible moisture could have gotten into the light enclosure from the factory.
Hi @tony-white
Finally got to taking our light apart and there doesn’t seem to be any issue by my eyes with the wiring, components, or signs of moisture. See attached pictures. Do you see anything, or have recommendations on next steps we could try?
Hi @offshoreRyan
With the system powered on, you could check with a multimeter that battery voltage is reaching the light PCB you’ve opened, at the red and black wires. You could also use an oscilloscope on the yellow wire to verify the integrity of the servo-style PWM signal.
Finally, trying a lower voltage like 24V may get things working? How are you creating the 48V, via a DCDC power supply?
Hi @tony-white
I’ll take some multimeter measurements when I get into the office tomorrow. We unfortunately don’t have an oscilloscope readily available. However as I mentioned in the original post, the other daisy-chained lights are usually behaving as we’d expect and the malfunctioning light is the first in the chain. I would expect there to be downstream issues if it were the PWM signal or press down terminals.
Our system delivers power as follows:
120VAC-in-> 120VAC/400VDC → teather → 400VDC/48VDC → lights Power & PWM
Changing our system to have 24V may be impossible due to space constraints, and requirements of other electronics.
Are the Lumen lights not designed to work with 48VDC?
Hi @offshoreRyan -
Understood - is the PWM signal voltage 48 as well?
The Lumen lights should work fine at 48V, but if you’re able to double check the supply voltage at the first unit, perhaps it is a bit over this and the other lights see lower voltage from voltage drop / power consumption at each light? Maybe trimming the output of your 48V output DCDC power supply is possible? Flickering can be associated with exceeding the voltage rating in some cases…
The PWM was designed to be the same voltage as the power signal. I believe our implementation is using an Arduino nano to generate the PWM then an optical isolation of some form to raise it to the 48VDC.
I will measure the input voltage to see if it may be slightly exceeding 48VDC.
If that turns out to be the issue I’ll have to consult with our electrical engineer on how we may tune the voltage.
