Lifespan of LED bulbs (A19)

[sw_ross]

I'm planning a lighting upgrade for some HID recessed fixtures that are located in the soffit around the perimeter of a school building.

The existing fixtures use a mogul base 50 watt bulb. Currently the lighting is probably 70% ambience/30% functional lighting. My plan is to bypass the ballast and use a mogul-to-medium base adapter, then use an LED bulb.

Originally my plan was to use a low wattage cob style bulb. I converted 3 of the fixtures and installed 3 different wattages and temperature colors of bulbs for them to review. The lowest wattage corn bulb I could track down online was a 14 watt 3000 K bulb.

Unfortunately all 3 were brighter than they wanted.

Then, just for experimental purpose, I changed 1 of them out for a standard A19 LED "60 watt equivalent" bulb that is 2700K.
That's the color and brightness that they want to go with.

The cob bulbs are rated for 50,000 hours. Everyone knows that your typical A19 LED bulb isn't going to last 50,000 hours!
I explained to them that they aren't going to get the hours out of an A19 as they would the cob bulb, but they said the cob bulb was brighter than they wanted and they prefer the light that the A19 puts out.

2 Qustions:

1) Is anyone aware of a cob bulb that is rated for less than 14 watts with a temperature color of 3000k or less?

2) If I end up going with the A19 LED bulb, can you recommend a source for a LED bulb that lasts more than 6 months?!

These fixtures aren't a 100% PITA to get into to change out the bulb, but still a fair challenge (especially for your typical maintenance employee).

Thanks!

 

[winnie]

I'm interested in seeing the answer to this. The LEDs themselves, if driven gently, will last for a very long time. So the question is one of the driver electronics and the manufacturer guarantees.

I'd suggest contacting a couple of the manufacturers, the driver circuit probably includes a simple resistor used to measure the current being driven through the LEDs, and by changing this resistor the power of the lamp could be changed. Perhaps you can get lamps modified to be dimmer at a reasonable price.

-Jon

 

[Besoeker3]

I don't know about the experiences of others. We started using LED panel indicator lamps in 1992. It was a cement works projects for two large variable speed fan drives which run 24/7. There have been no reported failures.

 

[winnie]

LEDs for illumination are a somewhat different beastie than LEDs for indication.

The LEDs for illumination themselves are actually fluorescent lamps using a blue semiconductor junction combined with a phosphor layer. The phosphor layer tends to degrade over time, especially with heat.

The LEDs are operated at relatively high power, and so need an efficient driver circuit, generally a switching power supply. This power supply is subject to various failure modes.

LEDs for indication often use a simple resistor to limit current from an ordinary constant voltage power supply, and are generally single color LEDs rather than white (though more 'modern' units might use white LEDs with color filters to maximize the engineering inelegance but minimize SKUs.) They will last until the machine around them rusts away.

-Jon

 

[Besoeker3]

LEDs for illumination are a somewhat different beastie than LEDs for indication.

The LEDs for illumination themselves are actually fluorescent lamps using a blue semiconductor junction combined with a phosphor layer. The phosphor layer tends to degrade over time, especially with heat.

The LEDs are operated at relatively high power, and so need an efficient driver circuit, generally a switching power supply. This power supply is subject to various failure modes.

LEDs for indication often use a simple resistor to limit current from an ordinary constant voltage power supply, and are generally single color LEDs rather than white (though more 'modern' units might use white LEDs with color filters to maximize the engineering inelegance but minimize SKUs.) They will last until the machine around them rusts away.

-Jon

Not just for indication. We have been using them for our residential lighting for about a dozen years. So far, no failures.

 

[PaulMmn]

The commercially available LED bulbs for home use don't seem to like being used in ceiling fans... it's either a tail-side-up issue, or a vibration issue. I think all of my fans have open-ended shades.

 

[hbiss]

If you read the small print instructions on the box they aren't recommended for use in an enclosed fixture either. hmy:

That aside, these things could be made to last forever but that wouldn't be good for sales. Incandescent lamps were actually made with a finite life span for that same reason.

-Hal

 

[ramsy]

Not just for indication. We have been using them for our residential lighting for about a dozen years. So far, no failures.

Are they available on Amazon, or exclusive manufacturer, supplier, or model? Is there a product link, to read anything, anywhere?

 

[retirede]

The commercially available LED bulbs for home use don't seem to like being used in ceiling fans... it's either a tail-side-up issue, or a vibration issue. I think all of my fans have open-ended shades.

I converted almost every bulb in my house to LED about 7 years ago. I’ve had one A19 style failure and it was in a bath/fan combo fixture (enclosed) - my fans are all fine.

 

[hbiss]

I converted almost every bulb in my house to LED about 7 years ago. I’ve had one A19 style failure and it was in a bath/fan combo fixture (enclosed) - my fans are all fine.

Tell me what you are using. I'm lucky to get two years out of them. And for some reason with outdoor fixtures, it's almost like the shell or tip don't make good contact when you screw them in. They flicker as you wiggle/twist them, even dim. I clean the socket and center contact thinking this is because of corrosion but no good. I wind up using a different brand. Incandescent works fine and LED works fine in an indoor lamp. And this isn't in just one fixture, it's several different ones.

These things were supposed to be the greatest thing since sliced bread but they are nothing but trouble.

-Hal

 

[hbiss]

Are they available on Amazon, or exclusive manufacturer, supplier, or model? Is there a product link, to read anything, anywhere?

Wouldn't do us any good, they would be 240V over there.:weeping:

-Hal

 

[Besoeker3]

Are they available on Amazon, or exclusive manufacturer, supplier, or model? Is there a product link, to read anything, anywhere?

We generally get them from our grocery store or a discount store in our shopping mall.

 

[MyCleveland]

SW....what is a "cob style bulb" ? Not familiar with the term.
I have a LED wall pack on a garage that is been up for 9 years and no failure yet.
Indoor shell base go in randomly one or two at a time but none are that old.
Replaced 4-60W incand in a clg fan/light because they kept failing in a short time...2+ years and no fails yet.
I keep the packing and receipts for the return if it comes to that.

 

[gadfly56]

SW....what is a "cob style bulb" ? Not familiar with the term.
I have a LED wall pack on a garage that is been up for 9 years and no failure yet.
Indoor shell base go in randomly one or two at a time but none are that old.
Replaced 4-60W incand in a clg fan/light because they kept failing in a short time...2+ years and no fails yet.
I keep the packing and receipts for the return if it comes to that.

Imagine a corn cob. Imagine each kernel was an LED lamp.

 

[MyCleveland]

Imagine a corn cob. Imagine each kernel was an LED lamp.

Now I'm hungry...
Can you give a mfg/model # or a link so I can these over please.

 

[PaulMmn]

Tell me what you are using. I'm lucky to get two years out of them. And for some reason with outdoor fixtures, it's almost like the shell or tip don't make good contact when you screw them in. They flicker as you wiggle/twist them, even dim. I clean the socket and center contact thinking this is because of corrosion but no good. I wind up using a different brand. Incandescent works fine and LED works fine in an indoor lamp. And this isn't in just one fixture, it's several different ones.

These things were supposed to be the greatest thing since sliced bread but they are nothing but trouble.

-Hal

I think you'll find the contact issue is because there's no lump of solder at the tip of the bulb! When fully screwed in the tip is not making good contact. Best solution I've found-- make sure the power is off, them GENTLY pull at the center contact and flex the metal so the contact is closer to the bulb. Of course, this only works with cheaper sockets, that just have an L-shaped contact with one free end.

 

[hbiss]

I think you'll find the contact issue is because there's no lump of solder at the tip of the bulb! When fully screwed in the tip is not making good contact. Best solution I've found-- make sure the power is off, them GENTLY pull at the center contact and flex the metal so the contact is closer to the bulb. Of course, this only works with cheaper sockets, that just have an L-shaped contact with one free end.

Yeah, did that while I was cleaning it. The shell of these lamps looks to be plated with something like chrome. Just looking at it I wouldn't expect it to be something to use on an electrical contact.

... what is a "cob style bulb" ? Not familiar with the term.

They are a cylinder dotted with LEDs. I've only seen them available as a replacement for high wattage HPS and MH lamps, they're about that size. Most have mogul bases and operate directly off the line making removal of the ballast and igniter necessary.

-Hal

 

[winnie]

Not just for indication. We have been using them for our residential lighting for about a dozen years. So far, no failures.

I'd either call you lucky or say that someone over there is demanding better quality. I always write the 'install date' on bulbs when I put them in. I usually get many years of life out of LED bulbs; some that I originally installed have not failed...but others die very quickly.

-Jon

 

[hbiss]

I'd either call you lucky or say that someone over there is demanding better quality. I always write the 'install date' on bulbs when I put them in. I usually get many years of life out of LED bulbs; some that I originally installed have not failed...but others die very quickly.

-Jon

You have to consider where they come from. China. I have no doubt that quality varies all over the map.

-Hal

 

[retirede]

Tell me what you are using. I'm lucky to get two years out of them. And for some reason with outdoor fixtures, it's almost like the shell or tip don't make good contact when you screw them in. They flicker as you wiggle/twist them, even dim. I clean the socket and center contact thinking this is because of corrosion but no good. I wind up using a different brand. Incandescent works fine and LED works fine in an indoor lamp. And this isn't in just one fixture, it's several different ones.

These things were supposed to be the greatest thing since sliced bread but they are nothing but trouble.

-Hal

I’ve always bought what was available as long as the lumen and color were what I wanted and the price was reasonable. I’ll check and see if I can identify the ones I have in my fans when I get home tomorrow.