ABSTRACT
This
paper shows an over view of lighting system (fluorescent lamp), the
types of fluorescent lamp (circling and tubular fluorescent fixtures), the
features of fluorescent lamp such as glass tube, choke or ballast and
starter, the working principle of fluorescent lamp, installation of
fluorescent lamp fixtures and fluorescent troubleshoot.
INTRODUCTION
A
fluorescent lamp or fluorescent tube is a gas discharge lamp that uses
electricity to excite mercury vapor.
A
fluorescent light is a type of electric discharge lamp consisting of a glass
tube filled with a mixture of argon.
The
fluorescent light is being used in many homes because of its many advantages
over regular incandescent lamps. It may be that in replacing broken or outmoded
fixtures your opinion will be sought leaving the way open for you to suggest
the substitution of fluorescent lamps for incandescent or old style lumines.
Fluorescent lamp give better illumination, with less current consumption, and
operate at lower temperature as compared to the incandescent type. In fact a
fluorescent lamp give off only one quarter the amount of heat produced by
filament lamps for the amount of light delivered.
CIRCLING
FLUORESCENT FIXTURE
With the
introduction of circular tubes called circling, rated at 40watts, the
fluorescent lamp became more attractive than ever to home owners. The circling
requires an entirely different type of fixtures, of course, than that of the
straight tubular lamps. Fluorescent lamp operate on an entirely different
principle from that of the ordinary filament incandescent lamp, which produces
light when its filament reaches white heat. The current enters the lamp through
the base, flow from one lead wire through the tungsten to the other lead wire
and back to the base.
TUBULAR
FLUORESCENT LAMP
The tubular fluorescent lamp is fitted with two prongs at each end. These
prongs fit into two small sockets located at each end of the fixture. The
prongs enter the slots in the sockets in a vertical position. After the tube is
inserted into the socket, it is given a 90-degree turn which locks it in place.
To remove the tube, simply give it a 90-degree twist and lift it down and out,
each lamp requires its own starter.
THE
BALLAST (CHOKE)
The ballast (choke) connected in series with the filaments and starters switch
serves two purposes. It supplies a momentary high voltage to start the lamp and
also limit the current through lamp after it has started and dropped the
voltage to a value that is low enough to keep the lamp lighted without damaging
it.
THE
STARTER
The gas
in the fluorescent tube has a high resistance when not in use, so it needs a
high voltage to start it glowing or lighting. The “starter” stores energy and
releases it all at once, causing on high voltage to make the tube glowing. And
once the tube is glowing, its resistance is lower, so it can continue to run
without the starter. It is a momentary switch which is closed when the lamp is
started but opens a few seconds and remains open until the lamp is turned OFF
and started again. The starters are marked according to the type and size of
lamp for which they are designed.
THE
WORKING PRINCIPLE OF A FLUORESCENT LAMP.
When the
fluorescent is first turned ON, current flows through the ballast, one
tungsten, a starter switch and the other tungsten back to the source. This
causes the tungsten to glow, heating the gasses in the tube and giving off
electrons, which are the basic units of current flow. After a moment the
starter switch opens and the ballast (choke) provides a momentary surge
of high voltage across the two ends of the lamp. This surge is high enough to
start an arc from one of the tube to the other. Once the arc is started a much
lower constant voltage will maintain it.
INSTALLATION
OF FLUORESCENT FIXTURE
In the
case of replacement. The first step is to disconnect the old fixture from the
wall or ceiling and take it down carefully. All fixtures, such as overhead
lights, are fastened to outlet boxes. This applies to ordinary incandescent
fixtures as well as fluorescent. For your own convenience, attach the base of
the new fixture to the old outlet box before completely assembling the new
fixture.
Cold
drafts and low temperature will often affect starter operation.
DARKING
OF TUBE
Fluorescent
lamps that have been in use a long time usually show a dense blackening at
either end. This is the effect of mercury upon the fluorescent coating of the
lamp as well as of deposits of material given off by electrodes. These deposits
cause darkening in the last part of the tubes life, whereas as much mercury
blackening occurs in the first hundred hours of use as in the next thousand
hours. Normal blacking or discoloration as describe above should
not be
confused with mercury condensation, which appears to be more common with that
1-inch- diameter tubes than the 11/2-inch size.
Mercury
deposits at the ends of tubes are often visible on new lamps, but should
evaporate after they have been in operation for a while. After a period of
none-use, the discoloration from mercury condensation may reappear when the
bulb is cool. Frequently, because of small droplets of mercury collection on
the lower or cooler part of the lamp, dark streaks appear lengthwise on the
tube. Mercury may condense at any place on the tube, if a cold object is
allowed to touch it for a short period. Such spots near the center section may
not again evaporate. When condensation appears in this lamp manner,
DENSE
SPOTS NEAR ENDS
Near the
end of their life, some fluorescent lamps develop a very dense black spot about
½ - inch wide and extending almost half way around the bulb, centering about
one inch from the base. This is normal, but should a spot develop early in the
tubes life, it is an indication of excessive starting or operating current.
ENDS OF
LAMP REMAIN UNLIGHTED
This is probably due to a short circuited capacitor in the starter; it is
possible that the switch contacts are welded together. In either case, it is
necessary to replace the starter. Starters which have been in service for some
time often fail in this manner.
If the lamp is not operating properly, it should not be left connected to the
circuit for any great length of time. If the starter is at fault and causes the
lamp to blink ON and OFF, this may reduce the lamp life. For this
reason, you have to install a new starter whenever you install a new
fluorescent fixture.
LAMP BLINKING ON AND OFF
This may simply be a normal lamp at point of failure. On the other hand if the
lamp is new, or has not been in service long, here are a number of factors that
can cause this action. First, the difficulty may be due to the starter.
The starter can be replaced. It is possible that the lamp may be faulty, and
changing the lamp would be the second step.
If unchanging lamp or starter only temporarily corrects the trouble, there is a
borderline cause of difficulty from some other source.
Low
circuit voltage, low temperature and cold drafts may cause difficulty of this
nature; several of these may be contributing factors.
FAULTY
STARTING
If the
lamp makes no starting effect, or starts slowly, it is likely that the starter
has reached the end of its life and should be replaced.
If the
starter replacement fails to correct the trouble the lamp should be tested in
another circuit, as there may be an open circuit in the lamp.
In doing
this check to see if the lamp makes proper contact in the lamp holder.
CAUTION
Fluorescent
lamps contain beryllium a rare, poisonous metal. It is used in the phosphor
coating inside the lamp.
If you
break a lamp, get away as fast as you can, breathing the fumes is very harmful.
If you
should cut yourself on a broken lamp, see a doctor immediately even if the cut
is small.
CONCLUSION
Conclusively,
the fluorescent lamp rays is more advantageous compared to the incandescent
lamp rays.
Having
gone through the steps above, with the understanding of the basic components of
the fluorescent lamp, operation and cautions, every user is expected to operate
and use the lamp better than before.
REFERENCE
1856 -
Heinrich
Geissler
1859 -
Alexandre-Edmond
Becquerel
1891 -
Nikola
Tesla
1896 -
Thomas
Edison
1895 -
Daniel McFarlan
Moore
1901 -
Peter Cooper
Hewitt
1911 -
William D.
Coolidge
1915 -
Georges
1926 -
Edmund Germer n color did not help
1927 -
Albert W. Hull
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