I have a fluorescent light fixture with four 4-foot-long tubes in the ceili ng of my kitchen. When I turn on the light switch, one of the outermost tu bes light but the other 3 lights do not light. When I slightly rotate the three unlit tubes in their sockets, they light. But, in a short time, one, two or all three of those previously-unlit tubes no longer light.
How can I keep the tubes from loosening in their sockets?
ling of my kitchen. When I turn on the light switch, one of the outermost tubes light but the other 3 lights do not light. When I slightly rotate th e three unlit tubes in their sockets, they light. But, in a short time, on e, two or all three of those previously-unlit tubes no longer light.
By "in a short time", do you mean they SELF-EXTINGUISH (while left on) after some period of time? Or, they STOP COMING ON after some period of time?
As you twist the tubes (when installing them), you should feel a "detent" that indicates when the tube is seated properly. Make sure the whole tube is aligned with the socket (i.e., so you aren't just adjusting one end while the other end remains skewed).
Have you tried swapping bulbs within the fixture (or with new bulbs)?
What sort of use does the light see? Fluorescent lamps tend not to like being turned on and off, often.
Presumably, these are rapid-staring ballasts (no starter to replace). Are you sure the fixture is properly grounded? (The "invisible" capacitance between the tube and the fixture is a key part of the starting circuit. If the fixture isn't grounded properly, starting suffers)
If this is a good fixture, it is worth replacing ballasts and keystones but if it is a good fixture you won't have to ;-) You can use a typing eraser to clean the contacts (power off) Bend them in a little to increase tension. Cross your fingers.
If you can find a color you like, a LED fixture might be worth buying.
ling of my kitchen. When I turn on the light switch, one of the outermost tubes light but the other 3 lights do not light. When I slightly rotate th e three unlit tubes in their sockets, they light. But, in a short time, on e, two or all three of those previously-unlit tubes no longer light.
I would start with four brand new bulbs. If that doesn't work, I would rep lace the ballast. If these are T12 bulbs there should two ballasts, one fo r each pair of lamps. You can rewire the fixture for one, 4 lamp T8 ballas t and four T8 lamps.
If the bulbs are getting loose from vibration, there are clips available to attach to the sockets to keep the bulbs from rotating. You can get them a t an electrical supply company.
As others have pointed out, it could easily be due to a loose/missing grounding wire to the fixture.
Part of the starting sequence involves using the tubes and the metal frame as a capacitor, and this requires the box to be grounded. (Well, not "requires", but makes a big difference).
It could be that when you reach up and rotate the tube, your body... acts as a replacement capacitor..
Replace the four tubes and if that does not fix it, the ballast. I've never had a problem with contacts, but I've seen that behavior many times with bad bulbs. We have hundreds of fixtures at work and never had to fix a contact.
My parents built the house in 1942. Over the years my Father installed numerous fluorescent light fixtures that use starters. Sixty+ years later, most of them are still working, some with the original bulbs.
In recent years, the only fluorescent shop lights you can buy are the type that connect to power circuits with a safety ground wire, and do not have starters. The old house does not have the safety ground, just neutral and hot wires. A new shop light in the garage worked when first installed, but not for long. The power switch has worn out from being toggled rapidly to get the light to come on!
I recently replaced the old shop light with a dual 4-foot LED version by Feit Electric, purchased at a local Ace Hardware store. However this light may not work as a replacement for the kitchen fixture. I suggest you look at LED fixtures sold in places like Lowes or Home Depot. They are more expensive than fluorescent, but will save you a lot of trouble over time.
Since you can buy a LED bulb for the same amount or less than a florescent now days I've started gutting the old fixtures here and putting in Edison sockets and LEDs in the old florescent fixtures. 2nd hand stores are a good source for cheap sockets. Remove the ballast drill a hole install the socket, wire it up, screw in the bulb. Checking the adds... Lowe's ...
6-Pack Warm White LED Light Bulbs SPECIAL VALUE Now $11.98 (was $13.98) Prices Valid 10/22/2015 - 10/26/2015
Watch the light output- specs say 750 lumens- Phillips HomeDepot specials were 800 and Wallyworld Great Value are 800 also. Good idea on bulb replace as 4 60 equiv at 3200 lumens are about equal to 1 f40/f34 ww at 2700-3100 lumens.
If the home is old and there is no ground, you can add one. However most older homes had BX which had an outer shell of metal, which served as a ground. Thus the metal box is grounded. So if the outlet is a 2 prong without ground, install a grounded outlet and make sure to ground it to the box with a screw in box and short piece of green or bare wire.
If there is no metal BX and they used the old "romex" without any ground, you can run some green wire from the main panel to that outlet box. (Hopefully without ripping open any walls). Code may not view this as legal, (I'm not sure), but it's not something that's harmful, and will get a ground to that outlet for that flor. light.
I'd replace the bulbs no matter what. They're not expensive and if the ones you have are not bad, they can be used again.
You can buy the replacement ends (sockets) at most hardware stores. Sometimes the ones you have may be bent backwards somewhat, because they are only screwed to thin metal. Apply a little pressure to them when the bulbs are removed and push them inwards (toward bulb) a little. Dont apply hard pressure or you'll break them. Just use your fingers. Look inside each socket and make sure the contacts are visible and lined up so they will contact the bulb's contacts.
If none of this works, then change the ballast(s).
I believe you mention in this thread that the fixture is only 3 years old, so I doubt the ballasts are bad and they are also the electronic type, rather than the old coil type. But anything can go bad, regardless of age.
If the home is old and there is no ground, you can add one. However most older homes had BX which had an outer shell of metal, which served as a ground. Thus the metal box is grounded. So if the outlet is a 2 prong without ground, install a grounded outlet and make sure to ground it to the box with a screw in box and short piece of green or bare wire.
If there is no metal BX and they used the old "romex" without any ground, you can run some green wire from the main panel to that outlet box. (Hopefully without ripping open any walls). Code may not view this as legal, (I'm not sure), but it's not something that's harmful, and will get a ground to that outlet for that flor. light.
I'd replace the bulbs no matter what. They're not expensive and if the ones you have are not bad, they can be used again.
You can buy the replacement ends (sockets) at most hardware stores. Sometimes the ones you have may be bent backwards somewhat, because they are only screwed to thin metal. Apply a little pressure to them when the bulbs are removed and push them inwards (toward bulb) a little. Dont apply hard pressure or you'll break them. Just use your fingers. Look inside each socket and make sure the contacts are visible and lined up so they will contact the bulb's contacts.
If none of this works, then change the ballast(s).
I believe you mention in this thread that the fixture is only 3 years old, so I doubt the ballasts are bad and they are also the electronic type, rather than the old coil type. But anything can go bad, regardless of age.
I bought 4 new florescent tubes for my kitchen fixture. Now, my kitchen is again awash in "soft white" light -- not "daylight", not "supreme soft whi te", not "industrial white", not "sunlight" not "workshop white". (Why can 't there just be "plain white" light?)
The fixture was properly grounded.
One of the old tubes had black ends and another one wouldn't stay lit. Sin ce the light fixture and the old tubes were 3 years ago, I figured that if two tubes had died, the other two aren't too far behind.
I also had a problem getting one of the tubes into its socket. I noticed t hat the plastic ring in the socket was no longer in line with the slot in t he socket. Turning the ring allowed the new tube to slip right in.
From what I can tell, they run by degrees Kelvin. The 4100k are crisp white with a bit of blue. The 3000k are distinctly yellow, and the 3500k are some where in the middle.
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