Make your own free website on Tripod.com

[ Home I Links I Glossary I Basics I F.A.Q. I FFA. Page I Circuits I Safety Tips I Ohms-Law I Add Url ]

Fluorescent Lamps

Fluorescent lamps are a large improvement over incandescent bulbs. They use less energy, they last longer, give off more light, throw off less heat, and are less expensive to run. One of the problems is the size, but fluorescent lamps with mogul type bases which fit into a regular light sockets are now available.
The fluorescent lamp is an electronic device. It functions through conduction in a gas. It consist of a long straight or circular tube containing a drop of mercury and a small amount of argon gas with electrodes sealed into each end. Both electrodes will function as cathodes (emitters of electrons into the enclosure). This will enable the lamp to conduct in either direction and therefore allow alternating current. The inside surface of the tube is coated with a fluorescent material known as phosphor which produces visible light when excited with ultra-violet radiation.

There are several methods of operation...
Preheat or switch starting! Switch starting is use in desk lamps or portable lamps. There are also manual and automatic starters which are placed in line with the ballast. Starters are very seldom used today.
Trigger Start! This method permits practically instant starting and is used for the smaller type lamps. Up to 30 watt lamps, and for 8 to 12 inch circline lamps.
Rapid start! This system is used with high output, very high output, or power groove tubes. These lamps should be used with rapid start ballast. Lamps glow as soon as they come on and come up to full brightness in about 2 seconds.
Instant start ballast! Through the use of higher voltage ballast these lights can be started without preheat. General lamps should not be used with these ballast or much shorter lamp life will result. Instant start lamps are available in 40 watt T12 and 40 watt T17 sizes.
Slimline (instant start) ! In 8 ft. lengths slimlines are one of the most efficient lamps made. In addition to increased efficiency the longer length reduces the number of lamps and fixtures required in a given installation. Slimline lamps are available in 72 and 96 inch lengths in T8 and 48, 72, and 96 inch lengths in the most popular T12 diameter.
Preheat lamps by use of starters ! There are still some fluorescent lights that are preheated with the use of starters. Starters are available in both standered or no blink type. Starters also come with automatic reset and manual reset. The manual reset (watch dog) is recommended because it eliminates flashing or blinking at the end of lamp life. saves ballast, and last much longer. If you have a problem with a preheat lamp try replacing the starter first.
Safety lamps (plastic coated) ! These lamps are wrapped in a coating that prevents broken glass from escaping when they are dropped or shattered. They are required in food plants and other areas where broken glass would be a problem.
Colors! Fluorescent lights are available in a range of colors. Red, gold, pink, green, and blue. All fluorescent lamps except gold and red are white when unlighted.
Dimmers! Forty watt T12 lamps can be dimmed from full brightness to nearly full blackout by means of special ballast and dimmers especially designed for this purpose.
CAUTION!!! Be careful handling fluorescent lamps. Broken pieces of glass from these lamps are very sharp and could cause severe cuts. Also the fluorescent coating could be harmful to your eyes. Wash hands after working with these lamps.

Ballast

Fluorescent lamps require ballast in order to provide the higher induced voltage needed for striking the arc, and after conduction has started stabilize the circuit to maintain the operating current at a steady value. You must use the proper ballast for type of lamp you have. The use and wiring diagram is usually labelled on the ballast. Early ballast failure could be caused by improper location of fixture which prevents proper heat dissipation. Also improper selection of ballast for type of lamp used, burnt out lamps, and line-voltage fluctuation. Most ballast are rated for 120 volt input. Use caution wiring these ballast. The secondary voltage is high and could cause a severe shock. Try not to touch ends of lights when inserting bulbs into holders. The safest thing to do is shut off power before inserting lamps.

Frequent Problems

Weather...
Fluorescent lights can be affected by muggy and damp conditions. Try to keep lights free of dirt and moisture by wiping with a dry cloth. Also cold weather can cause lights to blink off and on. If it is not to cold this will stop when ballast has heated. But freezing weather may require cold weather ballast.
Swirling and spiralling...
This is caused by particles of materials loosened in the light. This usually occurs in new lamps and most often will correct itself. You may try shutting light off for a minute.
Lights Blink off and on...
This usually indicates that the lamp is bad. Also could be low circuit voltage, low ballast rating, low temperature, moisture, cold drafts, also make sure fixtures and reflectors (the shade directly above the lamp) are properly grounded. These problems should be corrected or there could be damage to the ballast.
Lights go on and off...
If your lamp comes on for a minute or two than goes off for a while, and this repeats itself. Chances are you have a thermal overload in your ballast or fixture. When the ballast overheats it shuts off and comes back on when it cools. This usually indicates a ballast is going bad. It shoud be replaced.
Blackening on ends of lamp...
Early blackening on ends of lamp usually indicates. High or low voltage. Voltage should be within the ballast rating. Loose contacts with lamp holders. Make sure the lamps are securely seated in lampholders. Poor or cheap ballast. Try to use ballast with the U.L. label. Improper wiring of units could also cause a problem.
One lamp is off the other is dim...
If you have a fixture with multiple lights, these lamps are usually wired in series. If one goes bad the other will not light or be very dim. Even though only one bulb may be bad you might want to replace both lamps.
Ballast hum or noise...
Transformer noise is inherent in lamp ballast. Most ballast have noise ratings on the label, A thru F. With A being the quietest. In this instance you get what you pay for. Usually a better grade of light will be less noisy. Make sure the ballast is tightened securely in lamp fixture. Make sure the fixture itself is tightened securely. Voltage should be within the ballast rating. As the ballast starts to go bad it will get louder.
Ballast heat...
 These ballast are more or less transformers, which will generate heat as long as they have power. By removing the bulbs there will be a little less heat, because the transformer will not have to work as hard without a load. You can purchase lights with electonic ballast which make less noise and throw less heat, but also cost more.
Average Life...
Considering that there are no problems, it is not unusual for a lamp to last a long time or to go bad early. The better the light is made the better chance it has to last longer. You also could extend the life of the lamp by trying to avoid turning light off and on to many times. If you plan to leave for only a minute leave it on, but if you are leaving for a period of time shut it off.

Incandescent bulbs

 These bulbs are made by installing a tungsten filament into a coated glass that has the air pumped out and than reintroduces various inert gases. In other words, an incandescent Bulb Is just a tungsten wire sealed in a glass tube. The electric current passing through the wire heats it to incandescence, and the wire produces light.

Bulbs burn out to frequently.

 If you are burning bulbs to frequently you also might try using lower wattage bulbs. A 40 W bulb has a higher resistance than a 100 W bulb. Both bulbs will have the same voltage, the 100 W bulb must have more current. And that means the 100 W bulb must have a lower resistance. So the filament for the higher resistance 40 W filament must be heavier or have a smaller cross section. There is also a rough service bulb that is made with a heavier filament.
 It is important that line voltage feeding the bulb matches as close as possible the voltage rating of the bulb. If the bulb is rated for 120 volts and the feed for the bulb is 90 volts the bulb will be dim. If the voltage is 135 volts the filament will overheat and burn bright for awhile but will not last very long. The voltage tolerance is about 10 percent low or high.
  Since turning an incandescent bulb on and off doesn't shorten the life of its filament significantly, you do well to turn it off whenever possible. The same isn't true of a fluorescent tube--turning it on ages its filaments significantly (due to sputtering processes) so you shouldn't turn a fluorescent lamp off if you plan to restart it in less than about 1 minute. Always shut off all lights when leaving the house. Vibration can also cause shorter filament life. The best bulb on the market today is the CFL (Compact Fluorescent Lights) (Philips, Sylvania). These bulbs may cost 10 to 15 dollars, but will last about 10,000 hours.
New light fixtures require 90 degrees C. wiring.

 Newer light fixtures require that the temperature rating of the wire feeding these fixtures be at least 90 degrees C. This is the temperature rating for these light fixtures. It's important that the temperature rating for the wiring feeding these fixtures match or exceed the rating for the fixture. If the temperature rating of the wiring is lower than the 90 degrees C. required, the insulation around it becomes brittle and may break away. This allows arcing between bare wires, which causes heat that melts the fixture and could be a fire hazard.
 Look for the letters NMB on the jacket of the wire. The NM means nonmetallic sheath cable (Romex) and the B suffix means that the cable's conductors are rated for a maximum operating temperature of 90C 194F. We can assume that wiring made prior to 1984, without the B suffix, is rated at 60C 140F. This is the type of wiring found in most older homes that were built before 1982.

C.F.L. Lights

The best bulb on the market today is the CFL (Compact Fluorescent Lights) (Philips, Sylvania). These bulbs may cost 10 to 15 dollars, but will last about 10,000 hours.
 Just a few tips on what to look for when buying these bulbs. Find a good place to use them. A fixture that is left on more than the others. Make sure your CFL. is the correct size to fit your fixture. Try to get the same wattage as an incandescent bulb you might use. Lumens and watts are usually on the bulb and package label.
 Most CFL's come in two colors. Warm White (similar to incandescent) Cool White (White).
 If you use a dimmer be sure your CFL. is labled for use with dimmer. Photocells should be labled for use with CFL's.

Halogen Bulbs

 In incandescent bulbs, the tungsten material from the filament evaporates and deposits on the inner wall of the bulb. The halogen gas used in halogen bulbs strips tungsten off the wall and essentially puts it back on the filament. Halogen bulbs are generally 15% more efficient and last longer than normal incandescent bulbs. Because of its unique characteristics, a halogen bulb can be made smaller and with higher pressures than normal. The bulb glass is made of quartz or "hard glass" which allows the temperature to increase improving the overall efficiency.

Hazards

 Halogen bulbs burn much brighter and produce much more heat than standard incandescent bulbs. This could cause a fire hazard, and burns to skin.
 There are a few precautions you can take to help prevent some of these hazards.
 Place torchiere lamps in locations where they cannot be tipped over by children, pets or a strong draft from an open window.
 If you have a portable halogen torchiere lamp, make sure you don't use a bulb that has a wattage higher than 300, even though the lamp you own specifies 500 watts.
 The lamp should be turned off and unplugged before removing or replacing bulbs. As always, never attempt to replace or discard a bulb that is hot to the touch.
 Never touch a halogen bulb with bare fingers. The oils in your skin can cause hot spots on the glass envelope that may result in premature failure of the bulb. This "hot spot" puts a great deal of heat near the glass bulb and can cause the glass in the hot spot to warp and stretch. This causes a weak spot in the glass bulb which can break and thus shorten the life time.
 Halogen technology produces higher filament temperature which increases the amount of UV light being produced. To protect against ultraviolet radiation, some bulbs have a special glass or plastic shield which also protects against bulb explosions.

Dimmers

 Dimmers are used in almost every household. Turn a knob or press a lever and the light gets brighter or dimmer. These switches do have problems like humming and buzzing. You have to be sure when you have these devices you do not exceed the wattage at which they are rated. If you have a 300 watt dimmer and you use 500 watts worth of bulbs, the dimmer will overheat and you will hear humming or the dimmer will be damaged. Also try to use quality name brand bulbs with a dimmer. Cheap bulbs will have filaments that are weaker than the expensive kind. Buzzing bulbs are usually a sign of a cheap dimmer. Dimmers are supposed to have filters in them. The filter's job is to round off the sharp corners in the waveform, and the quick current jumps that can cause buzzing. In cheap dimmers, they are saving money on the manufacturing costs by cost-reducing the filtering, making it less effective. Perhaps the dimmer will be okay at some settings, but not others. If you have buzzing problems, it's almost always a cheap dimmer.

For more electrical information Click Here.

[ Home I Links I Glossary I Basics I F.A.Q. I FFA. Page I Circuits I Safety Tips I Ohms-Law I Add Url ]