Physical size of 2D compact fluorescents

[Andrew Gabriel]

I'm wanting to convert a glass sphere lamp (really squashed sphere shape)
to take a compact fluorescent instead of a filament lamp. Using a retrofit
compact fluorescent results in the light source being jammed up against
one edge of the sphere, and the light looks silly, very bright on one side
of the glass and in shadow on the other side. So I'm thinking of changing
the fitting to take a 2D compact fluorescent.

Can anyone tell me what power rating 2D compact fluorescent will fit
through a 6" (15cm) hole? I only have a 10W one, and that fits easily,
so I'm hoping I can go well above 10W. If someone has higher power ones,
could they measure the diagonal between outside edge of opposite corners
please?

Thanks

 

[Victor Roberts]

I'm wanting to convert a glass sphere lamp (really squashed sphere shape)
to take a compact fluorescent instead of a filament lamp. Using a retrofit
compact fluorescent results in the light source being jammed up against
one edge of the sphere, and the light looks silly, very bright on one side
of the glass and in shadow on the other side. So I'm thinking of changing
the fitting to take a 2D compact fluorescent.

Can anyone tell me what power rating 2D compact fluorescent will fit
through a 6" (15cm) hole? I only have a 10W one, and that fits easily,
so I'm hoping I can go well above 10W. If someone has higher power ones,
could they measure the diagonal between outside edge of opposite corners
please?

Thanks

I think you are stuck with the 10 watt unless the lamp will slip
through the 6" hole sideways. The 10 watt 2D is 3.6 inches on a side
of about 5" corner to corner (actually a bit smaller due to the
rounded corners.) The next larger size is the 16 watt which is 5.5
inches on a side, or about 7.5 inches from corner to corner. The 21
watt is the same size as the 16 watt. The 28, 38 and 55 watt 2D lamps
are 8.1 inches on a side. (This is all published data, as I only have
the 38 watt and 55 watt lamps here to measure.)

 

[TKM]

I think you are stuck with the 10 watt unless the lamp will slip
through the 6" hole sideways. The 10 watt 2D is 3.6 inches on a side
of about 5" corner to corner (actually a bit smaller due to the
rounded corners.) The next larger size is the 16 watt which is 5.5
inches on a side, or about 7.5 inches from corner to corner. The 21
watt is the same size as the 16 watt. The 28, 38 and 55 watt 2D lamps
are 8.1 inches on a side. (This is all published data, as I only have
the 38 watt and 55 watt lamps here to measure.)

It may not be important, but the smaller 2D lamps aren't listed in the RE
830 phosphor like the more common 55 watt. The 10W and 16W are listed in
the RE 827 phosphor though.

Terry McGowan

 

[jriegle]

What about the mini spiral CFLs? They're barely taller than a A19 lamp and
you won't have to change the fixture.
John

 

[JM]

quoting:

What about the mini spiral CFLs? They're barely taller than a A19 lamp and
you won't have to change the fixture.
John

There's spiral CFLs, and there's some neat A-lamp shaped CFLs, too. Let's
not forget about old Mr. Circline. A 20w circline is just about 6 inches
big, and does about 1200 lumens.

 

[Andrew Gabriel]

There's spiral CFLs, and there's some neat A-lamp shaped CFLs, too. Let's

Actually, A-lamp (or GLS as it's called here) doesn't give very good
light distribution from this fitting either, with the source extremely
off-centre.

not forget about old Mr. Circline. A 20w circline is just about 6 inches
big, and does about 1200 lumens.

Circline that small doesn't exist in UK (not seen them anywhere in
Europe either). There's only one common size you see here which was
originally ballasted by a series filament lamp on 240V supplies
(going back some ~40 years here;-). I think it's a 40W tube, around
16" diameter, but I don't have one to check. You don't see the
filament lamp ballasts any more, but that size has remained available
and is used in a small number of current cheap lamp designs.

 

[Victor Roberts]

There's spiral CFLs, and there's some neat A-lamp shaped CFLs, too. Let's
not forget about old Mr. Circline. A 20w circline is just about 6 inches
big, and does about 1200 lumens.

I'm not sure who's Circline you are thinking about. Both the GE and
Philips 20-watt Circline are 6.5" in diameter, too large for the OP's
6" hole, and they produce only 800 lumens from a low quality Cool
White phosphor with CR of 60 to 62. The 2D is far superior, as are the
various T5 circular lamps made by Philips and Sylvania.

 

[JM]

quoting:

Vic wrote:
I'm not sure who's Circline you are thinking about. Both the GE and
Philips 20-watt Circline are 6.5" in diameter, too large for the OP's
6" hole, and they produce only 800 lumens from a low quality Cool
White phosphor with CR of 60 to 62. The 2D is far superior, as are the
various T5 circular lamps made by Philips and Sylvania.

The Circline lamps I'm thinking about are the ones used in screw in CFLs.
tri-phosphor, 2700k - 2900k. One of the ones I own is Maxlite brand, the
1200 lumen rating seems accurate. One neat thing about these Circline CFLs
is that the lamp is not stuck in one position. The ballast could be screwed
into a horizontal-burn socket, while the lamp should be able to be tied in
place with some wire.

 

[Victor Roberts]

quoting:


The Circline lamps I'm thinking about are the ones used in screw in CFLs.
tri-phosphor, 2700k - 2900k. One of the ones I own is Maxlite brand, the
1200 lumen rating seems accurate. One neat thing about these Circline CFLs
is that the lamp is not stuck in one position. The ballast could be screwed
into a horizontal-burn socket, while the lamp should be able to be tied in
place with some wire.

I don't have data on the Maxlite. However, the GE 22-watt 8.5 inch
diameter Circlite is available with a 3000K rare earth phosphor. It
produces 1400 initial lumens for an initial efficacy of 63.6 lm/W. The
GE 21-watt 2D (also using a rare earth phosphor) produces 1350 initial
lumens for an initial efficacy of 64.3 lm/W, so these lamps have
comparable efficacy. I should apologize to Circlites the world around
<g>

 

[Andrew Gabriel]

OK, won't have access to the luminare again until next week, but
decided to take a chance on a 21W lamp fitting and ordered all the
bits.

Then I discovered how difficult it is to buy control gear and GR10q4
lampholders... Actually, I couldn't find any of my normal suppliers
in the UK who stock electronic control gear for 2D lamps, so I went
for the nearest match I could find -- a Philips Matchbox ballast for
15/18W T5 and 18/24W PLL, HF-MatchboxBLUE 124...
http://www.eur.lighting.philips.com...l/products/catalogue/fluo/hf_matchboxblue.pdf
Do people here think that's likely to work OK?

It may not be important, but the smaller 2D lamps aren't listed in the RE
830 phosphor like the more common 55 watt. The 10W and 16W are listed in
the RE 827 phosphor though.

I was after 2700K, so that's OK.

 

[Victor Roberts]

OK, won't have access to the luminare again until next week, but
decided to take a chance on a 21W lamp fitting and ordered all the
bits.

Then I discovered how difficult it is to buy control gear and GR10q4
lampholders... Actually, I couldn't find any of my normal suppliers
in the UK who stock electronic control gear for 2D lamps, so I went
for the nearest match I could find -- a Philips Matchbox ballast for
15/18W T5 and 18/24W PLL, HF-MatchboxBLUE 124...
http://www.eur.lighting.philips.com...l/products/catalogue/fluo/hf_matchboxblue.pdf
Do people here think that's likely to work OK?

It depends first on matching lamp current, and then having a
compatible voltage and enough starting voltage. Unfortunately GE does
not publish the operating current for their 2D lamps. All the data we
need is listed in IEC 60901 (2001-11), Single-Capped Fluorescent Lamps
- Performance Specifications, but I do not have a copy. So, lets take
another approach.

I believe the 21-watt 2D is formed from T5 tubing. I estimate that the
arc length is about 25". This is very rough and I will not object if
anyone else comes up with another estimate. The Philips 24-watt PL-L
is also constructed from T5 tubing and is about 12.5" long so its arc
length is perhaps 23". This seems close enough to say that the ballast
you bought *should* work, but this is not a guarantee

 

[Victor Roberts]

It depends first on matching lamp current, and then having a
compatible voltage and enough starting voltage. Unfortunately GE does
not publish the operating current for their 2D lamps. All the data we
need is listed in IEC 60901 (2001-11), Single-Capped Fluorescent Lamps
- Performance Specifications, but I do not have a copy. So, lets take
another approach.

I believe the 21-watt 2D is formed from T5 tubing. I estimate that the
arc length is about 25". This is very rough and I will not object if
anyone else comes up with another estimate. The Philips 24-watt PL-L
is also constructed from T5 tubing and is about 12.5" long so its arc
length is perhaps 23". This seems close enough to say that the ballast
you bought *should* work, but this is not a guarantee

Well, here is some additional data that indicates I may be wrong about
the ability of your ballast to operate the 210watt 2D.

Advance makes a "universal" ballast, their ICF-2S18-H1--LD that is
rated to run one or two 18-watt multi-tube lamps, two 16-watt square
(2D) lamps or one or two 21-watt square lamps. This implies that these
lamps all have similar operating current. (OK - the 21-watt 2D is
operated at a BF of 90% so it gets 90% of its rated current.

This ballast is also designed to operate on any voltage from 120 to
277 volts (actually 108 to 304) so it would work on 230 volt circuits
also. However, it is not approved for use in Europe or the UK, so you
legally cannot use it.

The key issue is that the Philips Matchbox data sheet gives the rated
current of 18-watt triple-tube lamps as 200 ma and they also give the
rated current of the 18-watt PL-L as about 300 ma. So, it seems that a
ballast designed for the 18-watt PL-L would provide too much current
for the 21-watt 2D lamp.

I really need to buy a copy of IEC 60901

 

[Andrew Gabriel]

Well, here is some additional data that indicates I may be wrong about
the ability of your ballast to operate the 210watt 2D.

Advance makes a "universal" ballast, their ICF-2S18-H1--LD that is
rated to run one or two 18-watt multi-tube lamps, two 16-watt square
(2D) lamps or one or two 21-watt square lamps. This implies that these
lamps all have similar operating current. (OK - the 21-watt 2D is
operated at a BF of 90% so it gets 90% of its rated current.

This ballast is also designed to operate on any voltage from 120 to
277 volts (actually 108 to 304) so it would work on 230 volt circuits
also. However, it is not approved for use in Europe or the UK, so you
legally cannot use it.

The key issue is that the Philips Matchbox data sheet gives the rated
current of 18-watt triple-tube lamps as 200 ma and they also give the
rated current of the 18-watt PL-L as about 300 ma. So, it seems that a
ballast designed for the 18-watt PL-L would provide too much current
for the 21-watt 2D lamp.

I really need to buy a copy of IEC 60901

Thanks very much Vic.
When the parts arrive, I'll try and see what happens.
I've got a true power meter, so in theory I can measure the
actual power draw of the lamp+ballast. Unfortunately, the
meter is currently located somewhere I won't be going for a
while, so that test will have to wait.

 

[Victor Roberts]

Thanks very much Vic.
When the parts arrive, I'll try and see what happens.
I've got a true power meter, so in theory I can measure the
actual power draw of the lamp+ballast. Unfortunately, the
meter is currently located somewhere I won't be going for a
while, so that test will have to wait.

Andrew - I just found the source of the error in my original
calculation. The 21-watt and smaller 2D lamps are made from T4 tubing,
not T5 as I had assumed. That means that the comparison of these 2D
lamps with PL-L on an equal arc length and power basis is not valid. I

 

[Andrew Gabriel]

Andrew - I just found the source of the error in my original
calculation. The 21-watt and smaller 2D lamps are made from T4 tubing,
not T5 as I had assumed. That means that the comparison of these 2D
lamps with PL-L on an equal arc length and power basis is not valid. I

Well, I tried it and it looks OK. In a temporary rig with the
glass dome over it all and probably less ventilation than it
will get when properly assembled, the ballast runs at about 60C,
whereas it's rated for up to 75C. I don't have any way to
measure the real power consumption at the moment -- I'll have
to retrieve my true power meter from another location and it
will be a couple of weeks at least before I can do that.