Replace old fluorescent tube with brighter?

[Clive Mitchell]

I believe it's in the kitchen, so there is a high possibility of putting ones hand into the seemingly motionless cake mixer. :P

[Victor Roberts]

[snip]

We do tend to differ on a number of lighting issues :-)

My understanding of that other post was that older electronic ballasts had some reliability problems and that make him shy away from even the modern, more reliable ones.

Its more than that, at least in the US. The best fluorescent lamps from an energy efficiency point of view are linear T5 and T8 lamps operating on high quality electronic ballasts. The best fluorescent lamps from a color quality issue are lamps using rare earth triphosphors. The least expensive triphosphor lamps are linear T8 lamps, with T5 next in line and T12 triphosphor lamps many times the cost of equivalent length T12 lamps. In the US at least, there are few EM ballasts for T8 lamps. So, the T8

• electronic ballast combination often has a lower initial cost than a T12 triphosphor lamp and an EM ballast.

As opposed to meow2222/NT I believe that we should try to save energy whenever possible. Your one lamp fixture may not save a lot of energy, but when multiplied by the number of people making this decision, the impact can be large.

Plus, I expect that when you see the cost of a triphosphor version of your current lamp that alone will start you looking at T8 systems.

[meow2222]

machinery strobing is possible with mag ballasts, but doesnt normally happen, and does not make it look stationary even when it does. Its not as much of an issue as is often thought, even in workshops. In a house its a non issue. And cake mixers are well interlocked :)

NT

[meow2222]

right, forgot if age was mentioned.

there are/were bipin thermal start fittings.

NT

[meow2222]

indeed, but that does not imply that the new fitting will be more reilable or as reilable as the old. On the whole it tends to be the other way round. One only need think bathtub curve to see that. Then theres the 2nd factor of a more price-aggressive market today. So its no surprise new goods dont have anything like the life expectancy of older kit.

Maybe then you could explain to us how travelling out to get a new fitting and putting it up will save more energy than the 7w the older fitting would consume with a T12 tube. Or even more to the point, the smaller amount of energy difference involved in using a T8 in an older fitting.

The OP has a T8 compatible system already. The OP is not in America.

NT

[Victor Roberts]

actually it happens 100% of the time on single lamp ballasts, through it is usually called flicker.

Since the depth of the modulation is less than 100% and it is unlikely that the mixer blades are rotating at a multiple of the power line frequency I agree with you on this point.

I would agree about the effect of the strobing on rotating machinery.

Unless you are one of the many people who get headaches from fluorescent lamp flicker.

And where do you find a mixer that is interlocked against a hand in the "blades" or whatever they are called? Certainly not mine.

[Don Klipstein]

Electronic components are getting less expensive and sturdier, more robust. Circuit designs are improved upon those that failed the test of time.

Bigger iron core items of older technology have not enjoyed as much reduction in production cost.

Modern USA 2-tube fixture with electronic ballast and two F32T8 lamps often has the lamps receiving guesstimate 29 watts each (most fluorescent lamps at a given current have both a slight decrease in power consumption when frequency gets to a few KHz or more and a very slight increase in light output when the frequency gets into the dozens of KHz), so the fixture consumes fairly close to 64 watts.

The USA-traditional dual-F40 fixture had the lamps receiving 40 watts each plus ballast loss that I guesstimate to be not much under 10 watts - for power consumption in the upper 80's of watts, approaching 90 watts.

So I believe that replacing F40T12 lamps with F32T8 ones and replacing the traditional dual-F40 ballast with an electronic one for two F32T8 lamps will reduce power consumption by somewhere around 24-25 watts.

Also, all popular F32T8 lamps made for "general lighting purpose" are triphosphor. These do not dull/darken most red objects and green objects the way most non-triphosphor fluorescents do. Non-triphosphor includes even most fluorescents with color rendering index around 90-92 although that range dulls/darkens reds/greens less than "old tech cool white and warm white".

1. I am speaking from and for America, the land of opportunity, including a megatonnage of fluorescent fixtures having significant room for improvement.
2. In a fixture having a magnetic 2-lamp rapid start ballast for two T8 lamps, replacement of the ballast with an electronic one will probably save more than 7 watts, since not only is the ballast loss reduced but also the lamps can be fed a little less power. This even goes to extent of giving the lamps only 29 or 28 or so watts each - slight shortfall in initial lumens is partially balanced out by improvement in lumen maintenance. Also, many lamps at same current consume 1-2 watts less at high frequency (a few KHz or more) than at low frequency due to reduction of a frequency-sensitive "anode fall" loss that most fluorescent lamps have. If the ballast output frequency is high enough for the "imprisonment duration" of a 253.7 nm photon to get above or even into the ballpark of a

1/2-cycle of the ballast output frequency, then the RMS "electron temperature"/"free electron kinetic energy" should be a couple/few hundredths of an eV less than if the lamp received low frequency AC and that can reduce the ratio of 184.9/253.7 nm radiation to an extent sufficient to have a slightly significant impact on phosphor deterioration. Lamps alone can have power reduction about 7 watts per pair by replacing a non-electronmic ballast with an electronic one, even without change of lamps. Ballast loss redution is an additional couple to a few watts. Savings get much bigger (typically over 20 watts per 2-"bulbs") in the many opportunities in "The Land of Opportunity" where such a change also includes replacing F40T12 lamps with F32T8 ones. The nominal "per bulb" wattage is decreased by 8 watts as in 16 watts per pair, in addition to the roughly 7-watt-per-pair underpowering that modern electronic ballasts fairly easily afford and in addition to saving a couple to a few watts in ballast losses from use of better higher efficiency electronic ballasts. That sounds to me like power consumption decrease of roughly 25 watts per pair of 4-footers from replacing T12 lamps and the iron-core ballasts for those with T8 lamps and an electronic ballast for T8 lamps.

- Don Klipstein ( [e-mail])

[Don Klipstein]

Although I agree with these presented facts, I do not find majority extent (slightly short of 100% even if hardly) of negation of some advantages of electronic ballasts to be any argument at all against arguments on basis of unrelated issues such as energy efficiency (reduce power consumption anywhere from roughly 7 watts to roughly 25 watts per pair of 4-footers, depending on who you listen to and also depending on what you do! Replace a pair of F40T12's and a non-electronic ballast for these with a pair of F32T8's and an electronic ballast for those and power consumption has a good chance of being decreased by roughly 24-25 watts - along with a majority of red and green colored objects being illuminated more brightly!

- Don Klipstein ( [e-mail])

[Andrew Gabriel]

Don, bear in mind that T12 fittings mostly vanished in the UK ~25 years ago, and also that T8 tubes outside the US/120V have different power ratings (they are designed to be used on the former T12 series ballasts, so 20W, 40W, 65W T12's become 18W, 36W, 58W T8's, so they can be used in most old T12 fittings).

T12 tubes are still available in larger retail outlets, but volumes are tiny compared with T8's, and smaller retail outlets won't stock T12's at all. Commercially, T12's haven't been used for a long time except for special applications.

[Andy Wade]

[UK]

Except of course for the 8 ft. length (now 100 W), which are still fairly common. I've always assumed this is for reasons of mechanical robustness - an 8 ft. T8 tube would be just too fragile - is that right?

[Andrew Gabriel]

In article , [e-mail] (Don Klipstein) writes:

I think there are significant differences between US and Europe here which dramatically change the economies of electronic ballasts between the continents.

In Europe... o Electronic ballasts are still mostly very expensive, and special order, and very limited selection. (As someone who has made a number of fluorescent fittings, I wish this wasn't the case, but it is.) o Iron core ballasts are very cheap (possibly much cheaper than in the US as ballasts for 230V mains operation are very much simpler). o My impression from reading US newsgroups is that iron core ballasts in europe are very much more reliable -- failures are pretty much unknown, but seem more common in the US (possibly in part because it's easier to use the wrong lamp with the wrong ballast, and possibly because they are more complex due to low mains voltage). Electronic ballasts just can't touch Iron core ballasts for reliability, as Iron core ballasts effectively last forever here. o Iron core ballasts in Europe are getting much more efficient due to EU regs (regs which were thought to phase them out, but just forced manufacturers to make them higher efficiency as that is still much cheaper that switching to electronic ballasts). They probably were in any case always more efficient than US ballasts, because they don't need the extra complexity for 120V operation. o Europe (at least the parts I know) moved away from T12 tubes decades ago, so the savings you are talking about with respect to switching to T8's we already did 25 years ago.

This is a USA-only tube. See my other post.

[meow2222]

So a problem with strobing does not normally occur.

A high level of light is output over a large percentage of the cycle, which is another factor.

ok, lets get more thorough about that then. There are 2 types of cake mixing machines:

1. high speed sharp bladed food processors that always have interlocks. Interlocking prevents any hand contact with moving blades. There is also the fact that in use one does not see spinning blades, but rather a mass of moving food. And the food does not move fast enough to apear stationary :)
2. low speed blunt paddle devices that are open. These move so slowly it is not possible to encounter a strobing problem with fl lighting on

50 or 60Hz. The blades move such a small amount between each half cycle that this simply can not be a problem.

So there is no risk at all in using mag ballasted fl lighting with cake mixers.

NT

[meow2222]

Replace a 40w tube with a 36w T8 and the power use also falls, though not as much as that, due to mag ballast losses.

However, that is not the real world comparison. The real world energy comparison also involves:

- energy used in transport to go get a new fitting

- energy used in manufacture of new fittings

- energy used in parts/materials of new fitting

- energy used in disposal of old fitting

- energy used in manufacturing, supplying and applying a coat of paint to the ceiling when end user notices the new fitting is not identically sized to the old, and the resulting paint appearance is bad.

If you do a real world energy comparison, it is more than hard to justify replacing the fitting on energy saving grounds.

It is also false to justify it on reliability grounds.

And in this case, it can not be justified on the basis of starting performance (which is typically lousy with glowstarts).

The claim of risk resulting from strobing in domestic situations is not valid, see above post about that.

So in short, a case for replacing the fitting just doesnt exist.

this surely is down to the tube, not the ballast. T12 UK glowstart fittings are T8 compatible. It is common to find T8 tubes in older T12 fittings here.

NT

[meow2222]

yes, nail on head. Yet another reason it would be pointless to replace the fitting with an electronic fitting!

NT

[Jeff Waymouth]

We don't have trouble with the strength of eight foot T8 lamps in the US. Many eight foot lamps are made in 1 inch diameter.

Jeff Waymouth

Andy Wade wrote:

[meow2222]

This is correct, but it is not the relevant fact. What is relevant is that the market is more cost driven and aggressive than in the past, and many electronic goods that were once reliable have become much less reliable, some to the point of disposable. This is primarily competition driven. Electronic reliability depends on design margins, and design margins depend on money. hence, not surprisingly, cheap electronic goods are not known for reliability.

To replace a mag ballast with en electronic one and expect greater reliability would be optimism over fact.

We dont have those tubes here. Nor do our standard fittings underrun tubes. Nor are mag ballast losses as high as you say there with modern fittings.

And lastly, the OP wanted more light output, not less, so isnt looking for an underrunning 29w system to replace 40w.

But the biggest issue here is that you've not addressed the energy cost of replacing the fitting. That will outweigh the trivial energy savings, which consist of mag ballast loss minus tronic ballast loss, which is all replacement could gain. If it even is a mag ballast at present, and it looks like it quite likely isnt, in which case savings of zero are as good as one could hope for.

this is immaterial, the options open to the OP are what counts here.

long snip

Youre describing the US market there.

NT

[Clive Mitchell]

In message , [e-mail] writes

Not all.

>2. low speed blunt paddle devices that are open. These move so slowly

Oh I rather think not. The CakeMaster 3000 has a variable speed DC drive with digital speed feedback and clearly has blade settings at 100 and

120 Hz. The motor is rated 3HP and the blades are barbed to facilitate good reduction of cake batter without lumps.

Several wealthy old ladies have quite literally been pureed to death in these kitchen monsters. In one instance the only clue to what had happened was that the mixing bowl was fuller than normal and had a fluffy slipper perched on it's edge.

[Victor Roberts]

I don't think anyone has claimed that electronic ballasts are more reliable than EM ballasts. After all, EM ballast have only a few parts and perhaps 20 connections, while electronic ballasts have perhaps 30 to 50 components and perhaps 70 to 100 connections.

EM ballasts have lives of well over 20 years, at least in the US, and it is not necessary for electronic ballasts to have better reliability than EM ballasts in order for them to be a good idea. If the life of an electronic ballast is

20 years, the room will probably be renovated before the ballasts die.

I can't quite figure out why you believe that electronic ballasts have serious reliability issues. It sounds like you are stuck in 1980, a few years after the introduction of electronic ballasts. I assume you own a TV set, some sort of music system, perhaps a DVD player, own a car with an electronic control system, travel in airplanes that use electronic control systems, and, yes, that computer that you are using to post your messages. I have not seem any mechanical computers that have newsgroup readers, so I assume you are using an electronic computer :-)

In 2005 there were 61,269,000 electronic fluorescent lamp ballasts sold in the US. See Current Industrial Reports - Fluorescent Lamp Ballasts: 2001, available at

this many ballast sold, we would have a lot of very angry customers if the failure rate was not very low.

[meow2222]

lol!

NT

[Victor Roberts]