Topic 'Dimming linear fluorescent lights' in forum 'Home Improvement' - dslreports.com

Re: Dimming linear fluorescent lights

Wed, 19 Dec 2012 19:59:47 EDT

whizkid3 posted :

4ft T12 fluorescent lights in the basement
I am wondering if it is time to relamp them or if it is the cooler weather.

Yes, they get dimmer as they age. It helps to clean the bulbs & reflectors. It also helps to use quality bulbs with full-spectrum color.

It only becomes time to re-lamp them, after they burn out.

Re: Dimming linear fluorescent lights

Wed, 19 Dec 2012 19:48:44 EDT

Raphion posted : Inductive ballasts will light the bulbs 120 times a second, electronic ballasts will light them around 22,000 times a second as a rule. So it's relatively trivial to figure out which kind you have, just get some shiny cylindrical object and move it very quickly through your field of view under the lamp's illumination, and if it traces stripes through the air, you've got an inductive ballast, if the trace appears smooth, it's electronic.

Re: Dimming linear fluorescent lights

Wed, 19 Dec 2012 18:50:07 EDT

leibold posted :

said by SparkChaser:

I re-lamp at least every 2 years.

Wow, I have some T-12 lights that I use daily and they are over 10 years old (they are only now getting to the point where I'm starting to think about replacing them).

For T-12 (and T-8 as well) a big factor for bulb life is how often they are turned on. Frequent on/off cycles will kill them quickly. Another factor is whether the cathodes are being heated continuously while the bulb is on or only during startup (which depends on the ballast type used).
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Re: Dimming linear fluorescent lights

Wed, 19 Dec 2012 18:12:36 EDT

shdesigns posted :

said by IowaCowboy:

They don't have starters so they have electronic ballasts.

Inductive ballasts for T12's would not have starters either.

Re: Dimming linear fluorescent lights

Wed, 19 Dec 2012 17:59:18 EDT

IowaCowboy posted : They do get turned on when we go down in the basement (such as to do laundry, retrieve possessions, etc). We are pretty good about turning the lights off when we're not down there and I've developed a habit of turning the lights off that sometimes I forget my mother is down there and I accidentally leave her in the dark :o but I do it due to the high electric rates in this part of the country. Sometimes they get left on. The tubes are starting to darken on the end. The fixtures are relatively new so the ballasts can be ruled out but I'll upgrade them to T8 when T12 lamps are no longer available. They don't have starters so they have electronic ballasts.

Re: Dimming linear fluorescent lights

Wed, 19 Dec 2012 17:54:19 EDT

SparkChaser posted : They definitely have a life time to consider. I re-lamp at least every 2 years. Of course, it depend on your usage.

Re: Dimming linear fluorescent lights

Wed, 19 Dec 2012 17:51:33 EDT

pike posted : Do you leave them on a lot? Fluorescent lamps definitely lose brightness with usage, but not necessarily age. Be sure to clean the diffusers/lenses (if equipped) and the reflectors first to see if that helps.

Re: Dimming linear fluorescent lights

Wed, 19 Dec 2012 17:49:18 EDT

John Galt posted : Are the ends of the tubes blackened?

Dimming linear fluorescent lights

Wed, 19 Dec 2012 17:40:38 EDT

IowaCowboy posted : I installed two hardwired 4ft T12 fluorescent lights in the basement of my unit back in 2009 or 2010 (can't remember exactly when) but they are not as bright as they were when I installed them. The basement is unheated but does not get bitter cold in the cooler weather. The duplex is newer construction (1988).

I am wondering if it is time to relamp them or if it is the cooler weather.