Change the ballast once, and T-8's work perfectly well (better than the T-12's they replaced in every fixture I've done so far.) You can get a decent ballast while you are at it, which is nearly impossible with new fixtures short of severely overpriced ones.
-- Cats, coffee, chocolate...vices to live by Please don't feed the trolls. Killfile and ignore them so they will go away.
Ecnerwal Inscribed thus:
I've just installed four 5" T8 fittings ! One is visibly much dimmer than the other three. Its also much heavier !
It didn't dawn on me at first, but the dim fitting has a conventional ballast choke, capacitor and starter, whilst the other three have electronic ballasts and a plastic cap over where the starter should be.
--
Best Regards:
Baron.
If I have to replace the ballasts in new fixtures, they *are* crap. Sorry.
My bet is that it will take a lot more than a few years for LED bulbs to be cheaper than CFLs.
-- - Don Klipstein (don@misty.com)
The 2000 volt figure is wrong. It's about 170 volts for the filter capacitor. The rectifier won't let it shock through the base contacts. And, in usual CFL electronic ballasts, the ends of the tubing are not across it. Otherwise, the tubing would get DC, which CFL ballast design avoids. Passing DC through a CFL would cause one end to be depleted of mercury and go dim.
There may be a ballast capacitor in CFLs with electronic ballasts, and it may have a couple or few hundred volts across it if the tubing breaks during operation, but its capacitance is only nanofarads - minor shock possible if you touch both electrodes of the tube without the unit being powered.
-- - Don Klipstein (don@misty.com)
While you seem to have tripped across crappy old .vs. new tech differences in ballasts, you can also get identical size/shape/weight electronic ballasts that will put out more or less light from the same bulb (using more or less watts to do so, which is part of why they are offered.) There will be a difference in the label, typically something like H-N-L for high/normal/low light output. Typically 115/100/77% of rated output. It only gets annoying when you find that it's easy to find (say) a 4-bulb low ballast at a reasonable price, and the same ballast in high (not to be confused with the HO ballasts/bulbs that are more like twice the wattage and output and need different bulbs) is hard to find and twice the price when you do find it. Been there, done that.
-- Cats, coffee, chocolate...vices to live by Please don't feed the trolls. Killfile and ignore them so they will go away.
st
dexample calculations show 1.4 microfarads at 700 volts is allowable for human safety: .5 c v v =3D energy .5 20 nf 700v 700v =3D 49 e-4 j =3D 5mJ
"Globemaker = RABID IMBECILE "
** Absolutely wrong.It relates to the ignition voltage of CCFLs.
but what is the actual capacitance in CFL?
** The only capacitor sometimes fitted to the base connections of a CFL is a suppression cap of about 47nF.After a CFL is removed from its socket, it may have a residual charge voltage up to 175 volts ( USA ) and 345 volts in most of the world.
Gives one a nip like a pin prick.
Shame about the GREAT BIG PRICK who is wasting our time here.
.... Phil
Ecnerwal Inscribed thus:
I complained to the distributor today about the dim fitting ! They have, grudgingly, agreed to replace it. Result (*)
--
Best Regards:
Baron.
I SNIP from here on basis of capacitor values and voltages that I did not find among the many dissected CFLs that I have experienced.
Enough said?
-- - Don Klipstein (don@misty.com)
I got a burn from an incandescent light bulb when I unscrewed it. When I tried to unscrew the bulb base from the socket a high temperature burning pain made me jump away. WARNING! Incandescent lightbulbs are dangerous when not plugged in. Tell the world, tell the department stores. Not Safe to Use. They cause radio interference. They buzz in the audio spectrum using air waves to send sound to peoples' ears. Do not buy them. 2000 degrees Fahrenheit are stored in a filament.
-- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" was written for you. See details at http://www.wescottdesign.com/actfes/actfes.html
Since introduction in the 1990s, high frequency ballasts have been used in general lighting fixtures with either rapid start or pre-heat lamps. These ballasts convert the incoming power to an output frequency in excess of=A020 kHz. This increases lamp efficiency. These are used in several applications, including new generation=A0tanning lamp=A0systems, whereby a 100 watt lamp (e.g., F71T12BP) can be lit using 65 to 70 watts of actual power while obtaining the same=A0luminous flux=A0(measured in lumens) as magnetic ballasts. These ballasts operate with voltages that can be almost 600 volts, requiring some consideration in housing design, and can cause a minor limitation in the length of the wire leads from the ballast to the lamp ends.
schematic using 6.8nf capacitors rated for voltages up to 1000v in CFL
Baron Inscribed thus:
Following up ! The replacement fitting has been installed and now all four look the same intensity.
--
Best Regards:
Baron.
The last sentence explains a lot.
-- It's easy to think outside the box, when you have a cutting torch.
The Sunbeam 100-watt ones and most other dollar store ones that don't outshine 750 hour 75 watt ones have a rated life expectancy of only 1,000 or 1,100 hours. They are outshone by Philips ones with rated life expectancy of 3500 hours and sold as "industrial service".
-- - Don Klipstein (don@misty.com)
I don't think I have more than a few of the Sunbeam 100 W bulbs. They were free, and no 100W bulb gives me even 750 hours before they fail or break. I do have a bunch of the 11 W Sunbeam CFL that I've used for years and not had one fail, yet. I only have a couple spots where I use any incandescent lamps. Most are in places that only get used a few hours a month. The exception is the pair of lamps on my gateposts. I use a pair of green 40 W incandescent lamps for about three weeks around Christmas. Then the 1.5 W LED lamps go back in the fixtures.
-- It's easy to think outside the box, when you have a cutting torch.
no way to get a 28 foot ladder into the stairwell? how about a shorter ladder and a scaffold ?
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There is only four feet between the door at the bottom of the stairs and a long wall, and the stairwell is only 38" wide so I don't see how you can get scaffolding or a ladder in and set up safely.
-- It's easy to think outside the box, when you have a cutting torch.
I don't see the problem. I'm not a scaffold rigger, but I've watvhed them construct it out of tubing, clamps, and planks, I'd be surprised if it took more than two man-hours to set-up a suitable ladder with a supporting frame.
-- ?? 100% natural
Of course you don't, but you'll cliam to have the solution, as usual and not having seen the situation.
Then I'll tell thm you're the man to call, since you're the expert. Like I said, there is no way to get a long ladder into that stairwell. Anything over eight feet won't make the turn.
-- It's easy to think outside the box, when you have a cutting torch.
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