DIY LEDs - The write-up

[TheFishMan65]

Yes test just as you intend to run. What we are trying to figure out is if the LEDs are getting enough voltage to turn on. If you read a low voltage (less than 36) then I would try using to 20 gauge and making the distance as short a possible.

 

[kcress]

You can not use 24AWG from the driver to the terminal blocks. Regardless of whether it's The Problem or not you need to replace it. You should use about the same size that was coming out of the driver, especially if you are running excessive lengths. Note that driver has 14AWG on the output. 16 would probably be enough for your 40 feet. If you mount it in the fixture you could just use the factory leads directly.

Yes, that long distance could be the problem. We don't have enough HLG240 setups to confirm that yet.

Since you need to dump the 24 anyway I'd do this.
I'd cut the 24 off a foot from the terminal blocks and hook it up - for just this test you can still use the 24. This will change two things. It will substantially drop the resistance Fish just described and it will shorten the wire length which can be a problem with these types of power supplies. Ideally the driver would be installed in the fixture, but probably that long is OK. Remember if the distance is 20 feet the round trip distance is 40 feet.

Once you temporarily shorten the wires you should first turn the inside current adjust pot down all the way. Next get some dark glasses. Turn on the unit with the intent of turning it right back off instantly. If when you turn it on one or more strings are dark, or one or more strings are extra bright you should turn it back off immediately and work out the that problem.

If everything looks pretty good you should immediately start measuring all the string currents by using your voltmeter across the resistors. Write them all down.

If still no light, measure the voltage at the two terminal blocks that are connected to the HLG leads. If you see 42V and no LEDs are lit come back and tell us.

Oh and MAKE SURE YOU DON"T HOOK UP THE HLG LEADS BACKWARDS!

 

[DFason]

Ok I am back!

After testing I still have the same thing. Nada. When I hooked my multi-meter to the LED outputs on the HLG and it wont read anything? When I had the wires off it read a solid 42v.


Added 16 gauge wiring and shortened the wires to around 5ft.

Bad soldering but it was a quick fix to see if this would work.

A few guys on NR said to try without the POT or shorting them.

After inspecting the strings I found two DOA's also. The odd thing is I tested them with a LPC-700 in a series and they still fire. I thought that they would not fire if in a series. The first one is the first in the series and the other is the second. Hmmm

Any other thoughts?

-Dave

 

[TheFishMan65]

OK it looks like you shortened the wires. If I am reading correctly they now light except for 2 LEDs, but the rest of the string does light. Those two lit earlier with the LPC. Have I got that right?

If so then I sound like the + and - got shorted together. You can check that with an ohm meter. Perhaps moving them around caused a short. Check each of the two leds all contact to the heatsink and all contacts to each other. Anothe thing you might try would be a 3 volt battery or diode check of each of the 2 suspect LEDs. If they light that way then more evidence of a short kind of depends on how the short behaves.

I had one LED that no matter how carefully I soldered and looked at it under a good magnifying glass for error would short. I finally used the other set of contacts and it worked fine the first time.

 

[Flazky]

I just got the eln60-48D driver and tested it out but the current adjuster doesnt seem to be working.

 

[kcress]

When I hooked my multi-meter to the LED outputs on the HLG and it wont read anything? When I had the wires off it read a solid 42v.

You need to slow down and be ridiculously clear if we're to successfully help.

I don't understand what you're saying here.

After inspecting the strings I found two DOA's also.

Two what DOA's??

I thought that they would not fire if in a series.

What exactly in series are you talking about?

The first one is the first in the series and the other is the second.

String? LED? ??

 

[juldelf]

where do you guys find the 65° optics on cutter website ?
I only found the 45° Frosted Wide Carclo optics

 

[TheFishMan65]

Flazky, A little more info. How are you testing it? What did you measure and what are the values?

+1 on what kcress said, we will try and help, but we need as much information as can be provided.

 

[DFason]

Ok here we go.

So I now have the following.
16 gauge wires from my driver to the terminals, then the fuses, then resistors and then 24 gauge from the terminals to the LED's. They are now only around 5' from the terminals to LED's.

When I had the drivers wires disconnected from the terminals I could get a solid reading of 42v ( dead on ). When I tried to hook the multimeter to the same spot with the wires connected to the terminals I did not get a reading? Should I try an test it on the resistor and see what I get? Am I testing it on the wrong spot?

I am now keeping the adjusting wires disconnected. I found that I need a much more adjustable pot to get it to work correctly. The data sheet it says keeping the ADJ wires disconnected it is 100% and shorting them is ~50%. This still had no effect on getting them to fire.

After trying multiple things I went back to test the strings of LED's with a Meanwell LPC-700. I two strings with one LED that would not fire and the rest were fine. The odd thing is the series of LED's will still fire even with the one not working. I thought if one LED in the series did not work they all would not work.
First string : D = Dead G = Good
D-G-G-G-G-G-G-G-G-G-G
Second String :
G-D-G-G-G-G-G-G-G-G-G
Could the two LED's that wont fire change anything? Of course I'll be swapping them out.

If it came down to it is there a problem running a high number of LPC drivers like there is with the ELN? I need to finish this VERY soon and if I have to I may have to run a high number of LPC's ONLY if it is safe.

cant thank you guys enough.

-Dave

 

[CJO]

When I had the drivers wires disconnected from the terminals I could get a solid reading of 42v ( dead on ). When I tried to hook the multimeter to the same spot with the wires connected to the terminals I did not get a reading? Should I try an test it on the resistor and see what I get? Am I testing it on the wrong spot?

Try reading across the resistor.

I thought if one LED in the series did not work they all would not work.

It depends on whether they failed open or closed. If they failed open, the string will still work.

CJ

 

[TheFishMan65]

You got a reading it may have been zero for the voltage, but the meter said something (unless maybe it was on the wrong scale). If it read zero then something is shorting the + and - minus from the HLG. Find that.

Can you get a picture of where you are testing with 'no reading'? Can you measure the output of the meanwell?

DO NOT RUN MIXED LENGTH STRINGS. It looks like the strings are 11 LED long?? maybe I miscounted or you missed type. DO not use the 10 (or 11) wroking with the 11 (or 12). They will have less of a voltage drop and will hog the current and could blow the remaining LED in those strings. Since they used to work before you replace them check the resistance (should be infinite) between the + and - of the bad LEDs maybe a short occured if so try and find (you may need to take the LED out for the test). If no short try the diode test on your multimeter. Seems odd that just one would go, but maybe.

 

[der_wille_zur_macht]

Could the two LED's that wont fire change anything? Of course I'll be swapping them out.

Depends on why they are not firing but generally, YES that can change things. At the least, as fishman suggested, they can cause the strings to be imbalanced, which throws the chances of things working right out the window.

If it came down to it is there a problem running a high number of LPC drivers like there is with the ELN? I need to finish this VERY soon and if I have to I may have to run a high number of LPC's ONLY if it is safe.

Yes. The LPCs have poor power factor as well. You may find another meanwell that doesn't have poor power factor, but IMHO you need to fix the problems you have, not just switch drivers - I really don't think the problem is the driver in this case. If it's dead LEDs, then swapping in new ones should let you use the HLGs as planned.

But, my money is on multiple shorts to the heatsink. This can absolutely cause the symptoms you are seeing and it is the #1 most common problem when people say "my array doesn't work."

 

[wfournier]

DO NOT RUN MIXED LENGTH STRINGS. It looks like the strings are 11 LED long?? maybe I miscounted or you missed type. DO not use the 10 (or 11) wroking with the 11 (or 12). They will have less of a voltage drop and will hog the current and could blow the remaining LED in those strings. Since they used to work before you replace them check the resistance (should be infinite) between the + and - of the bad LEDs maybe a short occured if so try and find (you may need to take the LED out for the test). If no short try the diode test on your multimeter. Seems odd that just one would go, but maybe.

I have heard this over and over but I wonder is this theoretical or observed in practice? I hooked up two strings of LEDs in parallel last night to an LPC-35-700 just too see what sort of output I would get. One string is 12 XP-E's and the other is a mix of 10 XP-G's and 3 XP-E's for a total of 13 LEDs. Worked just fine with no visible difference in brightness of the LEDs (at least of the same type, XP-G's looked slightly brighter as would be expected). I did this experimentally and felt that in this case it was fairly safe because even if one string hogged the current it would still only be 700 ma.

Edit: oh and the output was pretty impressive, with 40° optics I was seeing 100 PAR at 30" and it was still at 50 about 10" off center meaning I was getting an area of about 24X20 at 30" using less than 30 watts.

 

[der_wille_zur_macht]

It is 110% real and observed in practice. It's simple math based on elementary principles of electricity. Stop using your eyes to judge light output, they are poorly suited to the job.

 

[DFason]

All my strings are 11 LEDs. I am not mixing anything either.

Der - I'll look over again but I'm almost 100% sure nothing is being shorted from the heatsinks. I have the thermal pads that block a good 1/4"-3/8" around the star to make sure I would not get a short. Like I said before I've tested with the LPC on every string and they work. If I had a short on one of the strings it should show up when I am testing them correct?

-Dave

 

[TheFishMan65]

Do they all still work with the LPC? Now that would be really weird.

 

[der_wille_zur_macht]

If I had a short on one of the strings it should show up when I am testing them correct?

You cannot assume that - if you had shorts in more than one string, then changing configurations (i.e. running all strings in parallel vs. running single strings on single drivers) would certainly change the functional result.

Of course I cannot say you do or do not have shorts, but from what you've posted I can say that multiple shorts COULD act like that. At any rate it's really easy to test for. Set your multimeter to continuity, clamp one probe to the heatsink, and go around to each LED touching the other probe firmly to each pad on each LED. If you ever get a reading or beep anywhere, you have one or more shorts.

 

[rcgates]

You cannot assume that - if you had shorts in more than one string, then changing configurations (i.e. running all strings in parallel vs. running single strings on single drivers) would certainly change the functional result.

Of course I cannot say you do or do not have shorts, but from what you've posted I can say that multiple shorts COULD act like that. At any rate it's really easy to test for. Set your multimeter to continuity, clamp one probe to the heatsink, and go around to each LED touching the other probe firmly to each pad on each LED. If you ever get a reading or beep anywhere, you have one or more shorts.

I've had a single LED in the middle of a string not light and the rest work, turned out to be a single strand of wire causing the short. Hard to see the one stray strand.

Check very carefully you should be able to find it, a multimeter is your best friend.

 

[der_wille_zur_macht]

Technically, in order for one or more LEDs to stop working, you need MULTIPLE shorts to the heatsink (or any other otherwise-isolated conductor not intended to be part of the circuit). It's wise to find and eliminate all of them - don't stop just because your fixture starts working, otherwise you may end up in a situation where your heatsink is live, which could be dangerous.

 

[The Grim Reefer]

Meters are pretty cheap. 10 or 15 bux is a small price to pay to take the mystery out of issues with a build costing hundreds of dollars.

I've been slicing and dicing my fixture making some changes. At one point I missed a wire I have forgotten to re solder. Good thing my heat sink wasn't grounded LOL! Took me a minute to figure out why half a string was working.

LED Coat is the bomb too. Allowed me to remove my splash shields.