400W LED Lights

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petersonra

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Northern illinois
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engineer
I was talking to a vendor today. He told me about an interesting fixture he is working on to do life cycle testing of 400W LED lamp assemblies.

The test fixture runs a bunch of them at a time. The light would blind you so it has to be shrouded for safety.

Coming soon to a parking lot near you.
 

Dennis Alwon

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Chapel Hill, NC
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400 watt LEDs are extremely bright and you definitely don't want them too low as they will blind you. My supplier has them displayed in their store but they were so bright they were hurting peoples eyes.

What is life cycle testing?
 

petersonra

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Location
Northern illinois
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engineer
400 watt LEDs are extremely bright and you definitely don't want them too low as they will blind you. My supplier has them displayed in their store but they were so bright they were hurting peoples eyes.

What is life cycle testing?
they run them at elevated temperatures to see how long they survive.

I think he said the plates they are mounted on maintain a constant temperature of 100 deg C, but maybe it was 150 deg C. Don't recall exactly, but it was downright warm though.
 

Dennis Alwon

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Chapel Hill, NC
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Right now I am not much impressed with LED. I bought 10 led outdoor flood bulbs and after 3 or 4 weeks 2 of them started strobbing. I have seen this issue time and time again.
 

Electric-Light

Senior Member
400 watt LEDs are extremely bright and you definitely don't want them too low as they will blind you. My supplier has them displayed in their store but they were so bright they were hurting peoples eyes.

What is life cycle testing?

I doubt there's such thing as a 400W LED, but this thing must look like a bubble wrap.
HIDs and high power density fluorescents are the same when it comes to glare due to high ssurface brightness.

This 400W LED can do what that new ceramic discharge lamps can't?
 
Right now I am not much impressed with LED. I bought 10 led outdoor flood bulbs and after 3 or 4 weeks 2 of them started strobbing. I have seen this issue time and time again.

Dennis,

It seems to occur when the DC power supply experiences a short and start crow-baring. It happened with a system I installed at home and found the short, removed it and all was well.

Seen it also on a Crouse-Hinds unit, but don't know what they have done, probably just called the supplier and they replaced it as in this installation there wer several hundreds purchased as replacements over time for VMV-s.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I doubt there's such thing as a 400W LED, but this thing must look like a bubble wrap.
HIDs and high power density fluorescents are the same when it comes to glare due to high ssurface brightness.

This 400W LED can do what that new ceramic discharge lamps can't?

No idea. I did not even know they came in such a size. I think the idea is not so much that they are any brighter or use less energy as that they last for a very long time and do not require replacement real often. My understanding is 100,000 hours. Thats like 30+ years of 8 hours a day on time.
 

PetrosA

Senior Member
I'm guessing that a 400W LED array is going to output something like 40,000 to 50,000 lumens or more. If it's reaching 100-150 C, it could very well be over 50,000 lumens since they'd be driving the LEDs with high current to get that kind of output and heat. The newest Cree LEDs could output over 100,000 lumens from 400W (254 lumens/watt for latest generation).
 

BullsnPyrs

Senior Member
I'm guessing that a 400W LED array is going to output something like 40,000 to 50,000 lumens or more. If it's reaching 100-150 C, it could very well be over 50,000 lumens since they'd be driving the LEDs with high current to get that kind of output and heat. The newest Cree LEDs could output over 100,000 lumens from 400W (254 lumens/watt for latest generation).

Are you referring to what they are doing in the lab or to a real fixture?
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Dennis,

It seems to occur when the DC power supply experiences a short and start crow-baring. It happened with a system I installed at home and found the short, removed it and all was well.

This was just an LED bulb- nothing to do but bring it back. If it is a short then why is it happening all over the place. I have heard many people complain about the system LED's doing this also.
 

Electric-Light

Senior Member
Are you referring to what they are doing in the lab or to a real fixture?
R&D press release from April. It says at 350mA at room temperature and the light CCT is 4400K. Still pretty impressive if it was true. I believe this was a flash reading. The LED was kept at room temperature and measuring rig set up and ready,then power was applied and they capture the output in a split second so the JUNCTION temperature is around room temperature.

I'm unaware of LEDs getting more than 100 lumens per watt. 80 lumens per watt is awful generous.

This one seems to be the only exception so far that is in production.
www.lightingprize.org/pdfs/lprize_60w-stress-testing.pdf

Third party lab tested 90+ LPW, 90+ CRI. 10W 900 something lumen. The intended purpose is to substitute a 60W light bulb. Due to diminishing return effect, going to 10W from 14W is nothing like going from cutting down the power of 14kW HVAC to 10kW and with the current unit price, a whole bunch is not a realistic option.

When CFLs cost $10-15 each, acceptance consumer wasn't very high. They only became popular when they can be had for $2-3 each in a pack.

$47 is a big price to pay to go with 10W/900 Lm/91CRI rather than 13W/850 Lm/82CRI

90 LPW surpasses CFLs and other lamps of that wattage range, but surpassed by larger fluorescent and HID systems.
 

Electric-Light

Senior Member
I'm guessing that a 400W LED array is going to output something like 40,000 to 50,000 lumens or more. If it's reaching 100-150 C, it could very well be over 50,000 lumens since they'd be driving the LEDs with high current to get that kind of output and heat. The newest Cree LEDs could output over 100,000 lumens from 400W (254 lumens/watt for latest generation).

The new Philips 10W 900 lm lamp uses 18 high power LED elements. Assuming zero driver loss, that's 555mW. Using 92% driver efficiency I just guessed, that's 510mW per LED.

These power LEDs can take a lot more than 0.5W each, but doing so reduces efficacy. Using more elements to reduce operating power per element increases efficacy but drives up cost and limits applications. The said lamp above costs $50-60 and its only meant to replace a 30cent 60W bulb.

It's fine if the purpose is flood light.

To get focused beam on something like a long range flashlight, you'd want to drive the element to maximum possible power and that comes at a great compromise, because available power is REALLY at premium while operating on batteries.
 

TNBaer

Senior Member
Location
Oregon
90 LPW surpasses CFLs and other lamps of that wattage range, but surpassed by larger fluorescent and HID systems.

I think people will be a lot keener to move from CFL to LED than they were from Incandescent to CFL. The CFL conversion was done very poorly. People didn't realize what color temperature was and manufacturers put 5000K lamps on retail shelves. People don't like the warmup time. They insist the lamps don't last as long as the package stated (I think heavy cycling is the issue).

The LED on store shelves seems to be heavily 27k. The product doesn't look goofy. It's instant on. LED is seen as a "sexy" product.

In the residential sector, LED can address most of the residential's consumer's complaints with CFL.
 

Electric-Light

Senior Member
I think people will be a lot keener to move from CFL to LED than they were from Incandescent to CFL. The CFL conversion was done very poorly. People didn't realize what color temperature was and manufacturers put 5000K lamps on retail shelves.
Disagree. This is an issue with LEDs, not CFLs. LED "bulbs" until the last 2-3 years have been 6500K. Lower CCT LEDs weren't commercially available until at least 2008. I'm not sure how far back you're looking, but CFLs have been 2700K for a long time. It wasn't until recent 3500K and 6500K have become available. Daylight is a newer choice that's available in CFLs.

People don't like the warmup time. They insist the lamps don't last as long as the package stated (I think heavy cycling is the issue).
3 hrs PER CYCLE is not realistic in homes except for maybe outdoor porch light. If 3 hrs/day consists of multiple 15 minutes uses, it does shave a lot of life like you said.

Not all CFL failures are due to lamp failure. it is often due to integral ballast failure. If CFL was made with aluminum heatsink shell, ballast failure would be reduced. Ballast failure isn't as frequent with externally ballasted CFLs. Cold cathode CFLs do not suffer from reduced life due to power cycling, though they've had limited success. The stabilized state efficacy isn't quite as good as hot cathode CFLs.

The LED on store shelves seems to be heavily 27k. The product doesn't look goofy. It's instant on. LED is seen as a "sexy" product.
That's only in the last few years. Earlier LED bulbs were made with hundreds of small LEDs and they were 6500K.

In the residential sector, LED can address most of the residential's consumer's complaints with CFL.
LED lamps are heavy and cost $50 each. The latter is a big gripe with consumers. Heavy lamps limit applications. Swing arm type lamps will not stay up. It will hang down with horizontal mounts like on vanity fixtures. They're even more heat sensitive than CFLs, so they may have trouble in any application that limits free airflow across the heat sink.

Reduced cooling may lead to failure or output reducing throttling.

For uncompromised light quality, there is really no replacement for incandescent. Motion sensor switches are very effective when applied correctly and much can be done in implementation of software in the switch. How often do you need the bathroom, shed, closet or laundry room lights to remain on for over 30 minutes with no motion inside? I don't see this very often. For exceptions, the switch's software can be programmed to apply 8 hour override by pushing the button five times quickly... or something like that.

For residential lighting, LPW isn't especially important. If you already get 50 LPW, the cost to double that far exceeds the cost saved.

LEDs do have their place in special application where demand is at higher premium than energy, for example on battery power or generator power. You could have infinite fuel, but demand is limited by generator capacity.

Squeezing every bit of lumens per watt only makes sense where the total energy usage is very large or where demand and power are both very scarce and have direct significant impact like back light on battery powered computers and smart phones.

LEDs for general purpose lighting is like organic food. Plenty of intangible perceived values and definite high cost.

Regardless of real benefit, if organic food sells and conductive to bottom lines or brand building, that's all that matters in capitalism.
 
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BullsnPyrs

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