QA

How To Check A Fluorescent Light Bulb

How can you 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 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.

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 do you test a fluorescent light with a multimeter?

Turn the setting on the multimeter to “Ohms.” Touch one probe to the white wire and the other to a colored wire. The meter will display a direct short or continuity. If no reading is displayed, there is a problem with the ballast. Replace it as soon as possible.

What happens when a fluorescent bulb burns out?

Expect the light to dim as it nears its end. When it does burn out, expect a dramatic pop and a distinct odor. The CFL bulb might even produce smoke while the base of the bulb turns black.

Why are my fluorescent lights not working?

A dead fluorescent can be caused by lack of electrical power (tripped breaker or blown fuse), a dead or dying ballast, a dead starter or a dead bulb(s). defective starters, defective bulbs or a defective ballast. IMPORTANT: Flickering fluorescent tubes can cause the ballast to overheat and fail prematurely!.

How do I know if my ballast needs to be replaced?

2. Look for warning signs that the ballast is failing. Buzzing. If you hear a strange sound coming from your bulbs or light fixture, like a buzzing or humming noise, that’s often a sign your ballast is going. Dimming or flickering. No lights at all. Changing colors. Swollen casing. Burn marks. Water damage. Leaking oil.

Will a bad ballast burn out bulbs?

The ballast itself can go bad, which causes lights to flicker or even appear to be burnt out, when in fact they aren’t. They require maintenance and energy to power, on top of the power used to light the fluorescent bulb. They are a large part of the equation when using fluorescent lamps.

What is the voltage of a fluorescent tube?

Many fluorescent ballasts are now universal voltage, meaning they can be run on line voltage from 120 to 277 volts. For international or industrial use, 347-480V ballasts are available.

Do fluorescent lights flicker before they burn out?

Without a properly operating ballast to limit the light’s current, a fluorescent lamp connected to the electrical source would quickly and uncontrollably increase its current flow—causing the lamp to burning out. This is why a degrading ballast will cause the fluorescent lights to flicker.

What will happen if one of its light bulbs burn out?

If one bulb burns out in a series circuit, then this will break the circuit. Unlike in a parallel circuit – where each light has its own circuit – so even if one bulb burns out, the remaining bulbs will still function.

What should you use to check the voltage in the ballast?

Test the ballast’s voltage with a multimeter. Attach the multimeter’s leads to the sockets at the ends of the ballast. If the reading is not between five and nine volts, replace the ballast. Adjust the multimeter to measure frequency and replace the ballast if the reading is not between 20 and 50 kilohertz.

How do you test a light bulb socket?

TURN OFF POWER TO THE LIGHT AT THE BREAKER PANEL BOX AND REMOVE THE SOCKET Turn the power off to the socket. Test the socket by attaching the clip of the continuity tester to the hot screw terminal, the black wire lead. Then, touch the probe to the metal tab in the bottom of the socket. The tester should glow.

How do you check a ceiling light with a multimeter?

How to Check a Light Socket With a Voltmeter Hold either lead on the metal socket casing. Touch the bulb at the bottom of the socket with the other lead. Record the reading. If it’s somewhere close to 120 volts, the fixture is good.

How do I know if my UV light is working?

For most residential UV lamps, the elapsed time is about 9000 hours, or one year of continuous use. After this time, you may very well still see the blue glow. Again, that’s more a sign that the lamp is still getting power and not an indication that your water is fully inactivated.

How much does it cost to replace a ballast in a fluorescent light?

A replacement ballast costs about $10-25 depending on capacity and brand. The bite is that an electrician trip charge (which includes 30 or 60 minutes work) is going to be $75-150 probably – for about 5 minutes work on each light fixture.