Rolling candy cane type of flourescent?

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ritelec

ritelec

Senior Member
Location
Jersey
I've replaced ballasted and the florescent doesn't fully ignite.
I go back in a few days and things are fine.

Replaced a ballast today, the home owner picked up 4- 4' T 8's and there fixture didn't work so they called me.

I replaced the ballast, the lights lit, no problem. 4 hours later I received a call that one of the bulbs are flickering.........
So I go back and the fluorescent (phosphorus) in two bulbs on one side of the fixture from the splice area are rolling but the lights are somewhat lit,,
I switched the fully lit bulbs from the other side to that rolling side and the rolling side to the lit side.... all bulbs are lit fully..
What gives?

The only thing I could tell the owner is I've had not fully lit in the past that light after they warmup ????? that I don't make the bulbs or ballasts...

Not too professional.

What causes this? Especially after they were lit and warmed up. What might I do or say if she calls back tomorrow with "flickering bulbs"?

??? pick up another ballast and 4 more bulbs and replace them on me... ok....... then "what if" they still roll and don't fully light??

oh my

suggestions?
 
Sorry no pic

In the past the bulbs that don't fully light would be like wavy.

This candy cane was like the white and red stripe on a candy cane

Imagine an old barbers candy cane sign as the white and red would spin.

Just like that. The white was not fully lit and the red would be the fully lit. Spinning from one side of the bulb to the other. Slowly. Like the barber sign :- )
 
171201-2035 EST

See https://en.wikipedia.org/wiki/Fluorescent_lamp for a very good discussion on these lights. This discussion on fluorescents won't easily and directly answer your question.

It is my guess that reduced mercury bulbs and ballast design may have created operational problems that were seen less often in the past. The successful operation of a fluorescent bulb is dependent upon many different details, and operating conditions.

Somewhere I have some 1940 fluorescent lights. When we got the 1940 lamps they were an outstanding improvement over incandescent. I need to see if they still work. I have some from 1943 or 1944 that still work.

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gar said:
171201-2035 EST

See https://en.wikipedia.org/wiki/Fluorescent_lamp for a very good discussion on these lights. This discussion on fluorescents won't easily and directly answer your question.

It is my guess that reduced mercury bulbs and ballast design may have created operational problems that were seen less often in the past. The successful operation of a fluorescent bulb is dependent upon many different details, and operating conditions.

Somewhere I have some 1940 fluorescent lights. When we got the 1940 lamps they were an outstanding improvement over incandescent. I need to see if they still work. I have some from 1943 or 1944 that still work.

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.
Click to expand...

I have had that issue with lights in my basement from time to time, usually under high humidity conditions. I just touch the ballast cover and they come to full brightness.
 
I have stopped replacing ballasts, for no more than $9 a bulb you can switch to LED t8's and reduce your callback rates, unless you are in business to keep callbacks coming. The ones I use are dual or single end feed and work with all combinations of shunted or non tombstones. 5 year warranty on most of them. You can't beat it plus the light quality is better and you save your customer some money on their electric bill. Everyone wins.
 
171201-2136 EST

To slightly summarize the Wiki discussion.

Ionized mercury vapor is the primary source of UV photons to excite the phosphor that emits visible light photons.

Over time mercury is absorbed into the phosphor depleting the number of mercury atoms to emit UV.

Also going on is deterioration of the electron emitter electrodes reducing current flow and power input.

By going to induction excitation you eliminate the electrode deterioration, and therefore extend life. But you do not eliminate mercury absorption.

Plasma voltage drop is a function of many factors such as temperature, pressure, and gas mixture.

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ritelec said:
Sorry no pic

In the past the bulbs that don't fully light would be like wavy.

This candy cane was like the white and red stripe on a candy cane

Imagine an old barbers candy cane sign as the white and red would spin.

Just like that. The white was not fully lit and the red would be the fully lit. Spinning from one side of the bulb to the other. Slowly. Like the barber sign :- )
Click to expand...

Okay, I have seen that before. A common enough problem. I just never heard it called that.
 
I'm sure its been mentioned already- but they are called "power groove"


Never mind- I have not seen any fluorescents with a red stripe.
 
Don't worry about not looking professional. Just give his gar's explanation (above) and walk off while he's standing there with a dazed look :)
 
171201-1011 EST

From the Wiki discussion
Near the end of life, fluorescent lamps can start flickering at a frequency lower than the power frequency. This is due to a dynamic instability inherent in the negative resistance of the plasma source,[66] which can be from a bad lamp, a bad ballast, or a bad starter; or occasionally from a poor connection to power.
220px--Fluorescent_beat_effect.ogv.jpg


The "beat effect" problem created when shooting films under standard fluorescent lighting​

New fluorescent lamps may show a twisting spiral pattern of light in a part of the lamp. This effect is due to loose cathode material and usually disappears after a few hours of operation.[67]
Click to expand...
 
I have seen this happen on new lamps quite often. It usually clears up on it's own, cycling power sometimes clears it up. They usually only do it first time you energize them.
 
kwired said:
I have seen this happen on new lamps quite often. It usually clears up on it's own, cycling power sometimes clears it up. They usually only do it first time you energize them.
Click to expand...

Happens quite a bit with new bulbs, will only last a few minutes at most
 
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