QA

Question: How To Check Fluorescent Light Bulbs

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 fluorescent lights?

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 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.

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.

Why my tube light is 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 can you tell if the ballast is bad?

One probe of the multimeter should touch the hot wire connections, while the other touches the neutral wire connections. If the ballast is good, an analog multimeter has a needle that will sweep to the right across the measuring scale. If the ballast is bad, then the needle won’t move.

Why do my fluorescent lights not turn on?

The fluorescent tube won’t turn on No electrical power due to a tripped breaker or blown fuse. A dead or dying ballast. A dead starter. A dead bulb.

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 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.

Why do my lights smell like burning?

Overheating electrical wires and devices often emit a burning smell. Don’t use the fixture again until it has been repaired by a professional. For typical incandescent light fixtures, the burning smell may occur if you’re using an over-sized bulb or a higher wattage than is recommended for that fixture.

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.

How long do fluorescent tubes 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).

How do you test a fluorescent ballast with a digital multimeter?

To measure it, set your digital multimeter to around a thousand ohms resistance setting. Connect the black leads to the white ground wire on your ballast. Afterward, test every other wire with the red lead. When you do this test, a good ballast will return an “open-loop” or max resistance.

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 check the voltage on a fluorescent light fixture?

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.

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.