# Electric wall switch doesn't always work



## jimbotx (Apr 23, 2010)

I have a small office with the 'standard' florescent lights in ceiling. (4 tube, fat 4' tubes, with 2 ballasts) - In some rooms, I flip switch and no lights come on. Sometimes, if I flip the switch multiple times, it turns on; sometimes not. If I leave in 'on' position (up), they sometimes turn on in 10 to 20 minutes by themselves. In a room with 4 sets of lights, one or 2 sets turn on, and maybe in 10, 20 minutes later, the other 1 or 2 sets turn on. Could this be a corrosion thing? I replaced one switch - but no change. Help!!!


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## blues_harp28 (Jan 9, 2005)

Hi here in the UK - standard florescent lights, have what's called a Starter that is located along the metal part of the light fitting.
You may be calling them the 'ballasts'
They usually made of plastic [the top part at least] and screws into the main body.

It's head is the size of a small coin and if you look closely you will see it.
It is like a condensor and it's needed to boost the power going to the tube and without it, the tube will not light.
They are cheap and easy to replace.


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## JohnWill (Oct 19, 2002)

I doubt this is the switch. I'd first install new tubes, next suspect is the ballast. I've had lots of tubes go, and several ballasts. Very few current florescent lights in the US have a starter anymore, that's old technology.


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## jimbotx (Apr 23, 2010)

I don't think it's the bulbs - because I can flip the switch several times & all the bulbs turn on (sometimes); and sumetimes I can just leave 'on' and they turn on, when they feel like it. But I'll give it a try. It seems like it is an electrical problem .. but it's occassonial, not consistent. .. and sometimes it works fine.


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## Koot (Nov 25, 2007)

Lots of questions. How old are the lamps? Are the fixtures recessed (troffers) or are they surface mount? What's the ambient temperature where the ballasts are located (at, or in, the ceiling)? Do the lamps come On and then go Out, and are [then only] slow to come back On again? When did you first start experiencing this problem, e.g. maybe when the weather warmed up?

Since you have "fat" 4' lamps - that means you have T12 Rapid Start lamps. It also tells me that you have magnetic ballasts in lieu of newer electronic ballasts. These older ballasts have a temperature sensor to prevent overheating. You may be experiencing problems with the increased temperatures near (or in) the ceiling where the ballasts are located now that it's Spring and the weather is warmer. You did not mention anything about the lamps coming on normally (properly) when the weather is cool. Nor did you mention if the lamps go Out after they've been On for awhile (as if the ballasts are overheating). However, because (you did mention) the lamps randomly come On after 10-20 minutes my guess, without more information, is that various ballasts may have reached the end of their life and need to be replaced. Older magnetic ballasts were filled with potting tar, which has a tendency to leak out over the years. When this happens they overheat easily and fail. Even if they are not overheating ballasts do fail after 3-10+ years depending on their hours of use and ambient temperature conditions. And ... when they fail they often act as you've described yours.


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## jimbotx (Apr 23, 2010)

Koot - Thanks for your help.... answers are 1) lamps are old - I don't replace until they go out - I've been here 10 years - they were here before I was! 2) Lamps are recessed. 3) It probably is warm up there .. but I was having the problem when it was cold also. 4) Lamps NEVER go off once they are on 5) It could be that the ballasts are going out and yes they are the tar filled. (I have NEVER smelled anything as bad as the ballasts when they 'melt down' !!) So, if your guesses are my only options - my guess is that it may be ballasts getting ready to die. I hate to replace ballasts if not needed ($30 each x 2 per fixture).. so I may either (a) keep putting up with no lights/slow lights or (b) replace bulbs & see if it gets better. By flipping the switch several times (5, 6, 7 times) and having the lights come on as normal on the 7th time, still point to ballasts? Is there a downside to doing nothing (other than darkness)?


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## Koot (Nov 25, 2007)

jimbotx said:


> Koot - Thanks for your help.... answers are 1) lamps are old - I don't replace until they go out - I've been here 10 years - they were here before I was! 2) Lamps are recessed. 3) It probably is warm up there .. but I was having the problem when it was cold also. 4) Lamps NEVER go off once they are on 5) It could be that the ballasts are going out and yes they are the tar filled. (I have NEVER smelled anything as bad as the ballasts when they 'melt down' !!) So, if your guesses are my only options - my guess is that it may be ballasts getting ready to die. I hate to replace ballasts if not needed ($30 each x 2 per fixture).. so I may either (a) keep putting up with no lights/slow lights or (b) replace bulbs & see if it gets better. By flipping the switch several times (5, 6, 7 times) and having the lights come on as normal on the 7th time, still point to ballasts? Is there a downside to doing nothing (other than darkness)?


It sounds like you have a problem with your ballasts, but...you are almost certainly having problems caused by your lamps too. Some of your lamps probably have their cathode burned out or damaged (due to old age), which makes them hard to start. If you see a blackened end on the glass tube a couple inches inward from the metal end (where the pins are located), it's a pretty good indicator that the cathode is about to (or already has) see the end of its life.

You need to face the fact that your lighting fixtures are old. The ballasts are not very efficient compared to the newer electronics ballasts for the newer T8 (1" Dia.) lamps. And neither are the old style F40 T12 (1 1/2" Dia.) lamps. Your lamps do not produce efficient lumen output (per watt) compared to the newer T8 lamps. And oftentimes the wiring and lampholders are brittle and easily broken when changing lamps or ballasts. And assuming your fixtures are enclosed lay-in troffers, with prismatic lens, the old lens are probably helping to kill your cooefficient of utilization (usable light).

It's never fun spending money on replacing old stuff, but there comes a time when it's necessary...


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## Koot (Nov 25, 2007)

jimbotx said:


> I hate to replace ballasts if not needed ($30 each x 2 per fixture)..


If you change your own ballasts (I assume you do, but not sure) drop by a wholesale electrical distributor (Graybar, WESCO, GESCO/Rexel, etc.) and see what they'll sell you 2'x4' T8 lay-in troffers for. FYI - their stock cost for a competitive brand 4-lamp troffer is around $30.00 each (without lamps), which is the amount you say one replacement ballast is costing you.

PS - If you do decide to replace your old fixtures you'll probably have just as many footcandles of light (light level) using a 3-lamp troffer that uses T8 lamps. Also, one electronic ballast will handle all three (3) lamps... You'll save in electricity (reduced wattage), lamp cost (fewer number of lamps) and ballast cost (fewer total ballasts and much more efficient ballasts) without sacrificing light level. In fact, the light level may be even better by using just three T8 lamps in new fixtures compared to your old fixtures that use four T12 lamps. I know your future power consumption and replacement lamp and ballast costs will be lower...


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## jimbotx (Apr 23, 2010)

Wow - great idea .. (I do change them myself) .. so I can get the entire fixture for the price of a ballast? Cool! thanks


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## Koot (Nov 25, 2007)

jimbotx said:


> Wow - great idea .. (I do change them myself) .. so I can get the entire fixture for the price of a ballast? Cool! thanks


No, I said "their" cost is about $30 each, not "your" cost. However, when you're armed with knowledge of what their cost is - it makes it better for you to hopefully negotiate a fair price. Depending on how many you plan on buying your cost should be around $38-$40 range. If you buy only a few at a time it may be a few bucks more. Keep in mind they are in the "wholesale" business of selling to electrical contractors, institutions and industrial accounts. You're just a retail buyer looking for a good price, so your business is not overwhemingly important to them. They'll sell tens of thousands of these fixtures each year to their regular customers...along with stuff you have no idea what it does.


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