Dimmable CFLs? Spectacular Failures?

[Justin]

Here I am in 120v/60hz land looking for dimmable CFLs. I already have
the CFL dlay problem that annoys my family solved.
Now I'm looking for a CFL that is dimmable and available at Home Depot ,
Lowes or some other store that is common in the US.

Also, when CFLs fail - what happens? Can they catch fire? I know of a
neighbor who had one where the base died and basically melted. I had a
similar failure when I used a normal spiral outside and the bugs piled
up insite the spiral and the thing heated up like a toaster oven and
POOF! There's a burned hole out the side. Now I use an outdoor unit
that is fully enclosed.

 

[[email protected]]

| Here I am in 120v/60hz land looking for dimmable CFLs. I already have
| the CFL dlay problem that annoys my family solved.
| Now I'm looking for a CFL that is dimmable and available at Home Depot ,
| Lowes or some other store that is common in the US.
|
| Also, when CFLs fail - what happens? Can they catch fire? I know of a
| neighbor who had one where the base died and basically melted. I had a
| similar failure when I used a normal spiral outside and the bugs piled
| up insite the spiral and the thing heated up like a toaster oven and
| POOF! There's a burned hole out the side. Now I use an outdoor unit
| that is fully enclosed.

That depends one what kind of failure. Incandescent bulbs would normally
just burn out the filament with a breakage in the filament somewhere.

But I have seen some interesting failures of incandescent bulbs.

In one case, I suspect one of 3 in a fixture burned out, and the surge of
the fault current through the arc being extinguished blew out the others.
All three bulbs suffered various severe damage, including burn holes in
the base, destruction of the filament, and cracking of the glass stem in
one of them. They also had a lot of blackening inside the bulbs, but I
don't know if that pre-existed, or not.

My big worries with CFs are the mercury release risk, and the chance that
cheap electronics could cause a short circuit fault on failure.

Speaking of ovens, I also worry someone will put one inside an oven as a
replacement for a burned out oven light. They used to have standard base
sockets inside (maybe they still do ... I haven't checked in a couple of
decades).

As for dimmable lights, I'd focus on trying to green-ize as many of the
lights that don't need dimming, first, and for now put lower wattage in
the ones that do. Also, if doing wiring to fixtures, make as many of
them independently switchable as possible, so you can turn on the minimum
needed. For now I have CFs on outside lights. I don't like the light
for kitchen duty (I have both Fs and Is in the kitchen, but the Is give
a better quality of light, which I need in the kitchen when cooking or
cleaning).

 

[Don Klipstein]

Here I am in 120v/60hz land looking for dimmable CFLs. I already have
the CFL dlay problem that annoys my family solved.
Now I'm looking for a CFL that is dimmable and available at Home Depot ,
Lowes or some other store that is common in the US.

In recent months, I have been seeing GE dimmable spirals at Target.

Also, when CFLs fail - what happens? Can they catch fire? I know of a
neighbor who had one where the base died and basically melted. I had a
similar failure when I used a normal spiral outside and the bugs piled
up insite the spiral and the thing heated up like a toaster oven and
POOF! There's a burned hole out the side. Now I use an outdoor unit
that is fully enclosed.

CFLs with ballasts in them are normally UL listed. Avoid ones that are
not. I would also get ones of a major brand or of a highly promoted brand
by a major retailer to avoid false claims of UL listing. I have heard of
false claims of UL listing, and even once seen a definite case of this (on
a dollar store extension cord).

In my experience, the main offenders in terms of CFLs failing
spectacularly are the dollar store ones. I would avoid those because in
my experience:

1. Most do not even claim UL listing. One was subjected to a recall for
failure to make the plastic ballast housing out of flame retardant
plastic.

2. Some percentage is DOA or otherwise obviously defective.

3. They account for most of my experience of spectacular failures,
including one that had high smoke output and an orange "burning" glow in
its ballast housing (base area).

4. Their color rendering index is generally lower than that of
non-dollar-store CFLs. Warm color dollar store CFLs, in my experience,
have a spectrum like that of "old tech warm white" - which has the lowest
CRI of any common white/whitish fluorescent lamp.

5. Some have an icy cold "daylight" color but come in packages that say
"soft warm white light". Most that do not state their color are also the
icy cold "daylight" color.

6. In my experience, dollar store CFLs have a 100% rate of falling short
of claimed light output - occaisionally by a factor of at least 3.

7. CFLs with electronic ballasts included are supposed to have FCC
approval. In my experience, most dollar store CFLs lack any sign of FCC
approval, while containing electronic ballasts.

=============================================

My only spectacular failure so far of a CFL that is not a dollar store
one was one of the Lights of America brand, around 2001 or so.

=========================================================

I think your odds of quality in general are slightly improved if the
brand is a "Big 3" brand (GE, Philips, Osram/Sylvania). I also think
quality is likely to be better if the CFL has "Energy Star" approval.

- Don Klipstein ([email protected])

 

[[email protected]]

Also, when CFLs fail - what happens?

All of the ones I have had that died of natural causes, mostly GE and
Philips lamps, just didn't light up one day when switched on. One of
them made a popping noise when switched on, but that's about it. I've
also had a few that were murdered by having the glass broken, but there
I just got a loud pop (the same one you get when you break any evacuated
bulb) and then nothing.

The ones I have taken apart always seem to have a fusable resistor - a
low-value resistor that is designed to also safely act as a fuse - in
series with the center contact of the base. On a couple of lamps that
died of natural causes, this resistor opened up, probably due to a short
in the main switching transistor in the ballast.

For what it's worth, the Philips Marathon/Universal lamps have (had?)
a better design, IMHO, from a safety point of view. There was a tiny
circuit board (about 0.5" or 13 mm on a side) right in the base of the
lamp that had the fusable resistor, and then some small-gauge lead wires
(less than 18 AWG or 0.8 mm^2) to the main circuit board. The GE lamps
have just one circuit board, with small-gauge lead wires from the base
to the main circuit board; a short on the main circuit board would
result in these small-gauge wires trying to carry all available current
from the house breaker (15 to 20 A) for a brief period of time. Both
the Philips and GE lamps were UL listed, so they both met minimum safety
requirements, but I prefer the Philips design.

Matt Roberds

 

[Justin]

| Here I am in 120v/60hz land looking for dimmable CFLs. I already have
| the CFL dlay problem that annoys my family solved.
| Now I'm looking for a CFL that is dimmable and available at Home Depot ,
| Lowes or some other store that is common in the US.
|
| Also, when CFLs fail - what happens? Can they catch fire? I know of a
| neighbor who had one where the base died and basically melted. I had a
| similar failure when I used a normal spiral outside and the bugs piled
| up insite the spiral and the thing heated up like a toaster oven and
| POOF! There's a burned hole out the side. Now I use an outdoor unit
| that is fully enclosed.

That depends one what kind of failure. Incandescent bulbs would normally
just burn out the filament with a breakage in the filament somewhere.

But I have seen some interesting failures of incandescent bulbs.

In one case, I suspect one of 3 in a fixture burned out, and the surge of
the fault current through the arc being extinguished blew out the others.
All three bulbs suffered various severe damage, including burn holes in
the base, destruction of the filament, and cracking of the glass stem in
one of them. They also had a lot of blackening inside the bulbs, but I
don't know if that pre-existed, or not.

My big worries with CFs are the mercury release risk, and the chance that
cheap electronics could cause a short circuit fault on failure.

Speaking of ovens, I also worry someone will put one inside an oven as a
replacement for a burned out oven light. They used to have standard base
sockets inside (maybe they still do ... I haven't checked in a couple of
decades).

As for dimmable lights, I'd focus on trying to green-ize as many of the
lights that don't need dimming, first, and for now put lower wattage in
the ones that do. Also, if doing wiring to fixtures, make as many of
them independently switchable as possible, so you can turn on the minimum
needed. For now I have CFs on outside lights. I don't like the light
for kitchen duty (I have both Fs and Is in the kitchen, but the Is give
a better quality of light, which I need in the kitchen when cooking or
cleaning).

The reason I want to find a dimmable set of CFLs is not energy
efficiency... but PURE laziness. My parents house has a high ceiling
with two recessed dimmable fixtures. They were ahead of their time in
1973, as modern houses are built exactly like this. The problem is, the
lights are 30 feet up, and when one blows my parents call my sorry ass
over for dinner... and pull an "oh yeah there's the light 30 feet up"
you know the story.
So, I want to swap those out with long lasting dimmable CFLs and I never
shop at the Dollar store. For anything. Only once did I go in there in
college to buy some air fresher because I was farting massively. But
that's another story.

 

[Bob]

All of the ones I have had that died of natural causes, mostly GE and
Philips lamps, just didn't light up one day when switched on. One of
them made a popping noise when switched on, but that's about it. I've
also had a few that were murdered by having the glass broken, but there
I just got a loud pop (the same one you get when you break any evacuated
bulb) and then nothing.

Speaking of the GE dimmable.... I bought three of them to put in a ceiling
fan. I am not impressed. You need to turn the dimmer almost all the way up
to get them to light. Then, even after a reasonable warm up, when you turn
the brightness down on them with the dimmer, you get to about half
brightness - dimmer about at 1/4 - and they start flashing like disco
lights. The technology is not quite ready for prime time.

 

[Justin]

The problem is the interaction of the phase controlled
dimmer and the lap ballast. Dimmable CFLs with on-board
dimming controls work just fine. I personally think we need
to stop trying to use phase control dimmers with CFLs.

OK... what is a phase controlled dimmer? Is every switch dimmer a
phase controlled dimmer?

 

[[email protected]]

| Victor Roberts wrote:
|> On Tue, 1 Apr 2008 20:31:59 -0400, "Bob"
|>
|>> |>>>> Also, when CFLs fail - what happens?
|>>> All of the ones I have had that died of natural causes, mostly GE and
|>>> Philips lamps, just didn't light up one day when switched on. One of
|>>> them made a popping noise when switched on, but that's about it. I've
|>>> also had a few that were murdered by having the glass broken, but there
|>>> I just got a loud pop (the same one you get when you break any evacuated
|>>> bulb) and then nothing.
|>> Speaking of the GE dimmable.... I bought three of them to put in a ceiling
|>> fan. I am not impressed. You need to turn the dimmer almost all the way up
|>> to get them to light. Then, even after a reasonable warm up, when you turn
|>> the brightness down on them with the dimmer, you get to about half
|>> brightness - dimmer about at 1/4 - and they start flashing like disco
|>> lights. The technology is not quite ready for prime time.
|>>
|>
|> The problem is the interaction of the phase controlled
|> dimmer and the lap ballast. Dimmable CFLs with on-board
|> dimming controls work just fine. I personally think we need
|> to stop trying to use phase control dimmers with CFLs.
|>
|
|
| OK... what is a phase controlled dimmer? Is every switch dimmer a
| phase controlled dimmer?

I've yet to see a wall switch dimmer that says it is able to dim CFLs,
even if just the special class of CFLs known as dimmable.

My understanding of the dimmers in most common use is they clip the AC
waveform in time to limit the average power over time (of a cycle).

Variable transformers could be used, but they are expensive, bulky, and
perhaps less efficient. Still, I wonder if CFLs would dim better with
these than the other types of dimmers.

Personally, I'm holding out for improvements in LED lighting. LEDs can
be switched on and off at much faster rates to effect dimming, or they
can be selectively turned on and off (to light a room you need many of
them, so just turn some off for less light). But this is not likely to
be of any benefit where the need is to replace an incandescent bulb in
an existing incandescent (Edison base) fixture with something that can
be dimmed by controlling the mains voltage AC supply to it.

 

[Don Klipstein]

Since LED replacement lamps will use an electronic
driver, they will have the same problems with phase control
dimmers that we now see with CFL replacement lamps.

I have noticed that cold cathode CFLs tend to be dimmable. I wonder if
part of the problem with dimming hot cathode electrobnic-ballasted CFLs is
not a problem with electronic ballasts in general, but a problem with
particular circuits often used with hot cathode CFLs and not with cold
cathode ones, or with the cathodes being at the wrong temperature when the
lamps are dimmed.

Since cold cathode CFLs so far in my experience tend to be dimmable, I
have hope that LED lighting devices will show a better trend for
dimmability than hot cathode CFLs have.

- Don Klipstein ([email protected])

 

[[email protected]]

|>Personally, I'm holding out for improvements in LED lighting. LEDs can
|>be switched on and off at much faster rates to effect dimming, or they
|>can be selectively turned on and off (to light a room you need many of
|>them, so just turn some off for less light). But this is not likely to
|>be of any benefit where the need is to replace an incandescent bulb in
|>an existing incandescent (Edison base) fixture with something that can
|>be dimmed by controlling the mains voltage AC supply to it.
|
| Correct. Since LED replacement lamps will use an electronic
| driver, they will have the same problems with phase control
| dimmers that we now see with CFL replacement lamps.

So maybe what we need is "remote control" dimming, which is handled by the
light electronics directly, and fed to those electronics by various means
such as IR remotes, RF, X10, etc.

 

[Paul M. Eldridge]

Just on the subject of dimming in general... be it incandescent or
fluorescent, how many of us dim one or more lamps on a regular basis?
After spending a small fortune on dimmable electronic ballasts and
related hardware in my previous home, I discovered (a little late)
that I only operate my lighting in one of two states: "full power" and
"off".

With few exceptions, I'm much happier with multiple switching and
multiple layers of light that can be added or removed as desired,
without having to worry about colour shift/distortion and loss of
efficacy. Dimming strikes me as a fundamentally flawed proposition;
in effect, a rough handed attempt to make one size fit all.

In theory they sound great, but I really question their usefulness.

Cheers,
Paul

 

[Justin]

| Victor Roberts wrote:
|> On Tue, 1 Apr 2008 20:31:59 -0400, "Bob"
|>
|>> |>>>> Also, when CFLs fail - what happens?
|>>> All of the ones I have had that died of natural causes, mostly GE and
|>>> Philips lamps, just didn't light up one day when switched on. One of
|>>> them made a popping noise when switched on, but that's about it. I've
|>>> also had a few that were murdered by having the glass broken, but there
|>>> I just got a loud pop (the same one you get when you break any evacuated
|>>> bulb) and then nothing.
|>> Speaking of the GE dimmable.... I bought three of them to put in a ceiling
|>> fan. I am not impressed. You need to turn the dimmer almost all the way up
|>> to get them to light. Then, even after a reasonable warm up, when you turn
|>> the brightness down on them with the dimmer, you get to about half
|>> brightness - dimmer about at 1/4 - and they start flashing like disco
|>> lights. The technology is not quite ready for prime time.
|>>
|>
|> The problem is the interaction of the phase controlled
|> dimmer and the lap ballast. Dimmable CFLs with on-board
|> dimming controls work just fine. I personally think we need
|> to stop trying to use phase control dimmers with CFLs.
|>
|
|
| OK... what is a phase controlled dimmer? Is every switch dimmer a
| phase controlled dimmer?

I've yet to see a wall switch dimmer that says it is able to dim CFLs,
even if just the special class of CFLs known as dimmable.

My understanding of the dimmers in most common use is they clip the AC
waveform in time to limit the average power over time (of a cycle).

Variable transformers could be used, but they are expensive, bulky, and
perhaps less efficient. Still, I wonder if CFLs would dim better with
these than the other types of dimmers.

Personally, I'm holding out for improvements in LED lighting. LEDs can
be switched on and off at much faster rates to effect dimming, or they
can be selectively turned on and off (to light a room you need many of
them, so just turn some off for less light). But this is not likely to
be of any benefit where the need is to replace an incandescent bulb in
an existing incandescent (Edison base) fixture with something that can
be dimmed by controlling the mains voltage AC supply to it.

I tried a CFL W30 from Wal-mart... two words can describe it. Horse
and shit.
and yes they dim those lights often enough because they're near the TV
and one can get a glare.
I guess I'll go Halogen.

 

[Rusty]

I tried a CFL W30 from Wal-mart... two words can describe it. Horse
and shit.
and yes they dim those lights often enough because they're near the TV
and one can get a glare.
I guess I'll go Halogen.

I think this goes back to what Paul said earlier, the need to dim could
be a result of poor lighting design in a given room.

To me, the ideal room ought to have both open decorative lights and
recessed lights, and separate light switches should control both.

Another thing I just thought of, I have seen 3-way CFLs intended for
table lamps and such. How come I have never seen any 3-way light
fixtures? To me that could be a form of dimming.

 

[Justin]

I think this goes back to what Paul said earlier, the need to dim could
be a result of poor lighting design in a given room.

It was 1972 - at least they got the Foyer right.
The driveway, basement, phone jack location, landscaping...
They missed the boat on.

To me, the ideal room ought to have both open decorative lights and
recessed lights, and separate light switches should control both.

I understand what you're saying, but having a mission control switch
bank in the family room can be somewhat annoying.

 

[[email protected]]

| Just on the subject of dimming in general... be it incandescent or
| fluorescent, how many of us dim one or more lamps on a regular basis?
| After spending a small fortune on dimmable electronic ballasts and
| related hardware in my previous home, I discovered (a little late)
| that I only operate my lighting in one of two states: "full power" and
| "off".

I dim a few of the lights in my home. The reason is because I prefer a
lower level of light. So why not just put in lower wattage bulbs? The
reason for that is my father prefers a higher level of light when he
uses those lights.


| With few exceptions, I'm much happier with multiple switching and
| multiple layers of light that can be added or removed as desired,
| without having to worry about colour shift/distortion and loss of
| efficacy. Dimming strikes me as a fundamentally flawed proposition;
| in effect, a rough handed attempt to make one size fit all.

I do agree. I would have preferred to have stepped lighting where each
of the multi-bulb fixtures can run just 1 or 2 bulbs for me, and run all
5 or 6 bulbs for my father. I prefer the higher temperature white and
I don't get that with dimming.


| In theory they sound great, but I really question their usefulness.

They are a tradeoff. They happen to be more economical and practical for
most people. Alternative ways to have selective lighting levels would
involve more complex switching, additional wiring, and/or expensive
controller.

 

[[email protected]]

| On 3 Apr 2008 01:25:39 GMT, [email protected] wrote:
|
|>
|>|>Personally, I'm holding out for improvements in LED lighting. LEDs can
|>|>be switched on and off at much faster rates to effect dimming, or they
|>|>can be selectively turned on and off (to light a room you need many of
|>|>them, so just turn some off for less light). But this is not likely to
|>|>be of any benefit where the need is to replace an incandescent bulb in
|>|>an existing incandescent (Edison base) fixture with something that can
|>|>be dimmed by controlling the mains voltage AC supply to it.
|>|
|>| Correct. Since LED replacement lamps will use an electronic
|>| driver, they will have the same problems with phase control
|>| dimmers that we now see with CFL replacement lamps.
|>
|>So maybe what we need is "remote control" dimming, which is handled by the
|>light electronics directly, and fed to those electronics by various means
|>such as IR remotes, RF, X10, etc.
|
| Yes!

And if someone could make this cheap enough to sell enough to go to mass
production, a controller that interprets the light level requested from a
remote control as above, but switches multiple smaller lights on and off
to approximate the desired level. Consider a fixture that is an array of
many 6 volt 9 watt low voltage halogen lamps. You really would not want
to dim these by lowering the applied voltage. Instead, just switch them
on and off according to the "dimming" request signal. Thus you get the
same good quality white light at the intensity level desired. In areas
where the lower temperature light can be desired, supplement them with
ordinary incandescent lights running undervoltage (either by applying a
lower voltage to normal mains voltage bulbs, or using special bulbs that
are effectively intended for a voltage above the mains voltage). This can
also be done at the low voltage levels if the transformer is already a part
of the setup to allow using the same low voltage switching elements (relays
or solid state, whatever the case may be). If they can make fluorescent
or LED lights with the same effective lower color temperature in a good
quality, that may well be preferred over running incandescent lights in
such an inefficient way.

 

[[email protected]]

| I think this goes back to what Paul said earlier, the need to dim could
| be a result of poor lighting design in a given room.

The need to dim can vary by personal preference. I almost always prefer
a lower light level than my father (we are currently living in the same
house). Fortunately, we are rarely using the same space at the same time.
Fortunately, several lights do have dimmers.


| To me, the ideal room ought to have both open decorative lights and
| recessed lights, and separate light switches should control both.

Cost. People often avoid such things during custom home construction,
not realizing what they really end up wanting later on when it is much
more expensive to retrofit.


| Another thing I just thought of, I have seen 3-way CFLs intended for
| table lamps and such. How come I have never seen any 3-way light
| fixtures? To me that could be a form of dimming.

Cost. This requires extra wiring to support it. That's another piece of
copper wire that code requires to be as large as any other in the circuit.
The alternative is a controller at the point of the light and signals like
X10 to tell it what to do.

 

[[email protected]]

| Table lamps are fixtures. But you probably mean hard-wired
| fixtures. I don't know why 3-way hard wired fixtures were
| never developed, but it may be due to the fact that the
| wiring between the fixture and the wall switch would need
| one more active wire, which was not present in existing
| installations.

And today, it would add a substantial cost to the initial installation.
A remote IR/RF/X10 operated controller would be more practical for this
kind of thing. If you can entirely eliminate all of the AWG #14 wire
in switch loops or longer runs through the switch, it may well be an
economic win to go with remote controlled lighting.

I was investigating computer controlled relays to turn test computer boards
on and off a while back. I only needed 24 VDC control for that project.
But what I found was that a lot of the relays available were rated for as
much as 250 VDC/AC, and some for as much as 15 or 20 amps. Depending on
how they are integrated into the light fixture itself, it might not need
all that amperage rating to meet code and/or UL, and not even the voltage
rating when doing low voltage halogen lighting. At that point, who cares
about 3-way bulbs, anymore. Just put in half a dozen small single wattage,
possibly low voltage, bulbs and control how many to turn on.

 

[Don Klipstein]

you are absolutely correct Vic, and furthermore, the public erroneously
believes that there is a direct and proportional electrical savings when
dimming. Actually the amount of electricity consumed is less when dimmed,
but certainly not proportionally equal. And in the case of LED products,
this proves even more true.

Most white LEDs operate a little more efficiently when dimmed mildly,
moderately or moderately severely.

I can't say this is always true with the driver circuits however.

- Don Klipstein ([email protected])

 

[Don Klipstein]

perhaps I'm misinformed... and will readily admit it if so. I'm wondering
if perhaps the reason you site LED's as closer to proportion (light out put
to electrical consumption) is in reality because of the type of DIMMER being
used?

Overall luminous efficacy of a tungsten filament varies greatly with its
temperature. As a result, incandescent lamps have overall luminous
efficacy severely compromised when they are dimmed.

Put 50 watts into a 100 watt 120V A19 incandescent that produces 1710
lumens with 100 watts, and what comes out is about 20% of that 1710
lumens. At half power, overall luminous efficacy is about 40% of that at
full power.

This effect is a characteristic specific to incandescent lamps,
including halogen lamps. Fluorescent lamps and LEDs have overall luminous
efficacy not changing as much as input power is varied.

- Don Klipstein ([email protected])