QA

Quick Answer: How To Tell If A Fluorescent Bulb Is Bad

Look for dark areas at the base of the bulb. When bulbs age and have been used for a long time, brown spots will appear. If darkness begins to form at the ends of the tube, the bulb may be near its end. While they may still light, they are wearing out and will die soon.

How can you tell if a fluorescent bulb is blown?

How to Tell If a Fluorescent Tube Is Bad? Check the ends of the tube. If they appear darkened this indicates the bulb is burned out. Rotate the tube in the fixture if the bulb is not darkened on either end. Remove the bulb from the fixture if the bulb is still not illuminating.

How do you test a fluorescent light?

Set a multimeter to the ohm (Omega symbol) setting, then touch one tester probe to each of the pins at the end of the bulb. If the tester shows a reading between 0.5 and 1.2 ohms, the bulb has continuity. Repeat the test at the other end of the bulb.

What does a bad fluorescent bulb look like?

Take a bulb from a fixture working properly and test it in the flickering fixture; also look for black or other discoloration in the flickering bulb. Often a failing fluorescent light bulb will begin to darken or even look black at one or both ends. Eventually the bulb simply won’t light.

Why do fluorescent lights not turn on sometimes?

If you find your fluorescent light won’t turn on sometimes, there could be a variety of reasons why. It could be as simple as needing to replace the bulb or plug the light itself in; or, it could be something more serious, such as a blown fuse or a damaged/dying starter.

Do fluorescent lights go out?

Fluorescent bulbs can go for years without replacement—even when the ends start to blacken. Don’t worry about them until the light they put out starts to weaken.

How long do fluorescent bulbs last?

LED tubes last an average of 50,000 hours (roughly 16 years) while fluorescent T8 tubes last an average of 25,000 (roughly 8 years).

Why my tube light is not working?

If a fluorescent tube neither lights nor flickers when switched on, first check to see that the fixture is plugged in and that no fuse has blown or circuit breaker has tripped. If this does not help, try wiggling the tube gently in its sockets by rocking it back and forth and from side to side.

Why do fluorescent lights flicker?

In your lighting system, the ballast regulates the current flowing to the fluorescent lights and provides the voltage needed to start the lamps. The ballast takes in electricity and then regulates current throughout the bulbs. This is why a degrading ballast will cause the fluorescent lights to flicker.

How can you tell if a light ballast is bad?

Signs That Your Ballast is Bad Dimming or Flickering Headlights. If your HID bulb cannot produce its full brightness or strobe periodically, this is most probably a ballast problem. Strange Sounds. Headlights Not Working. Changing Light Colors. Constantly Blowing Fuse. Damaged Casing. Burn Marks. Water or Oil Damage.

How long should a fluorescent light ballast last?

According to the Certified Ballast Manufacturers Association, the average magnetic ballast lasts about 75,000 hours, or 12 to 15 years with normal use. The optimum economic life of a fluorescent lighting system with magnetic ballasts is usually about 15 years.

Do new fluorescent bulbs need to warm up?

All compact fluorescent lamps require a slight warm-up time for the electrical current to fully heat the cathodes and reach their full lumen output. When a bare spiral CFL is first switched on, it lights up with approximately 80% of its rated lumens, but it will heat up to its full brightness in about one minute.

Why do fluorescent bulbs fail?

Loss of Mercury Over time, as the mercury liquid is changed into a gas, some of that gas will become permanently absorbed into the phosphor coating. Since fluorescent lamps are now being made with lower amounts of mercury than in the past, this has now become a much more common problem for the failure of the fixtures.

How often should you replace fluorescent bulbs?

Typical lamp life for a fluorescent bulb is about 20,000 hours, but this can degrade as a consequence of frequent switching (turning on and off). Burning life is extended if lamps remain on continuously for long periods of time.

Do fluorescent lights fade over time?

Light levels decrease over time because of aging lightbulbs and dirt on fixtures, bulbs and room surfaces. Common bulbs, especially incandescent and fluorescent lamps, lose 20 to 30 percent of their light output over their service life.

Why do fluorescent lights last so long?

Each time you turn on a fluorescent tube, emission paste begins to fly off the cathode. Once the emission paste has been depleted from the cathode, this signifies the end of life and the tube burns out. Because of this the longer the tube is left on, the less emission paste darts off and the longer the tube lasts.

Can you replace a fluorescent bulb with LED?

Yes, you can replace fluorescent tubes with LED tubes or LED-integrated fixtures. If you just want to replace the bulbs, you can use plug-and-play, direct-wire, or hybrid LED tubes. Plug-and-play tubes are the easiest to install as they do not require any rewiring to the fixture.