New CFL bulb is dim

FredM · Dec 15, 2008

I just bought a 65W CFL and only the first ring of the bulb is fully lit the rest of them are dim. I doubt it is putting out the 3900 lumens it is supposed to.

Do these larger bulbs need a break-in time or should I take it back to the store for an exchange.

Marduke · Dec 15, 2008

How long have you left it turned on?

FredM · Dec 15, 2008

I think about 5 minutes runtime total. I have been moving it around to see if the socket was the problem.

JohnR66 · Dec 15, 2008

First run can take 5-30 minutes before lamp evens out. Worst case for me was a 4 foot tube F32T8 that took 30 minutes before it would even out. That was two years ago. It is still in service two years later.

Something about these newer amalgam lamps that require a first run burn in.

Manufacturers need to indicate this on the package to reduce returns.

jerry i h · Dec 17, 2008

I had the same experience. My kitchen is light by a single 100w incan fixture. So, I stuck in a 35w CFL (equiv to 150w incan) to get more light. First time I turned it on, nice: much brighter. I left to do a few things (not sure how long, but 1/2 hour is not unreasonable), and went back to get a beer, and GF was walking around in the kitchen wearing shades, saying: what the heck did you do the light? I looked up, and sure enough, the whole bulb was much brighter, and the kitchen had never been brighter. Better, this CFL seemed to be warm white, so seemed that much brighter.
I also have a 105w CFL; I am afraid to open the package.

LukeA · Dec 17, 2008

jerry i h said:
I had the same experience. My kitchen is light by a single 100w incan fixture. So, I stuck in a 35w CFL (equiv to 150w incan) to get more light. First time I turned it on, nice: much brighter. I left to do a few things (not sure how long, but 1/2 hour is not unreasonable), and went back to get a beer, and GF was walking around in the kitchen wearing shades, saying: what the heck did you do the light? I looked up, and sure enough, the whole bulb was much brighter, and the kitchen had never been brighter. Better, this CFL seemed to be warm white, so seemed that much brighter.
I also have a 105w CFL; I am afraid to open the package.

FredM · Dec 17, 2008

Yeah I love CFL's because you have much more freedom to adjust light levels in rooms that are to dark or to bright. My old houses garage had only one freaking light socket for the entire garage. The openers had their own lights but if you just wanted to go walk out there to get something it was rough. I put in a 100 watt CFL and problem solved.

It is generally a bad idea to go over 100W in a normal socket right? I guess they are all rated for 100W but going over that may be pushing it?

jerry i h · Dec 17, 2008

FredM said:
...It is generally a bad idea to go over 100W in a normal socket right? I guess they are all rated for 100W but going over that may be pushing it?

Depends: real answer, or the legal one? Technically, a 105w thingie in a 100w receptacle is a big no-no, and could (at least in theory) get you a citation from a building/fire inspector (like using one of those extenders, plugging in 8 different things into a 2-receptacle outlet, even though they are all low-current devices, and never all on at the same time).
In real life though, a 5% increase in the current through the wires and bulb receptacle is unlikely to be a problem. I do not know the usual margin of safety (is the limitation the wire gauge, or the method of joining wires? Any electricians know?), but I think it would be OK.

Resqueline · Dec 20, 2008

FredM said:
I just bought a 65W CFL and only the first ring of the bulb is fully lit the rest of them are dim. I doubt it is putting out the 3900 lumens it is supposed to.
Do these larger bulbs need a break-in time or should I take it back to the store for an exchange.

It is generally a bad idea to go over 100W in a normal socket right? I guess they are all rated for 100W but going over that may be pushing it?

My initial thought was that it's not working right but it's possible that cfl's are so low on mercury nowadays that it takes a while for it to evaporate inside. The reason it's brighter near the end is probably that the glowing filament there helps ionize the gas around it even if the main end-to-end current is too low. Perhaps the mains supply voltage is low? Try to get that measured if it doesn't help running it for 30 min's like John & jerry suggests.
All fluorescents needs a few minutes warm-up to attain full brightness, but their brightness is usually the same all along their length even so.

As for socket wattage, over here (europe) the bakelite sockets are limited to 60W - above that usually requires a porcelain socket. But the cfl's naturally have a much lower socket temperature both due to their high efficiency electronics in the base and to their larger surface area distributing the heat away from the socket. My guess is that you can go as high as you like even with a bakelite socket.

I've never seen as big cfl's as you are talking about over here btw..

New CFL bulb is dim

FredM

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Marduke

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FredM

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JohnR66

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jerry i h

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LukeA

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FredM

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jerry i h

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Resqueline

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