Why is fluorescent light flickering

We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may have an effect on your browsing experience. Trading for 10 years. Home Easy fixes for slow to start, flickering or faulty fluorescent tubes.

Easy fixes for slow to start, flickering or faulty fluorescent tubes. The electric current or arc excites the low-pressure mercury vapor which generates radiant energy, primarily in the ultraviolet or UV range. The inert gases instead of air that contains oxygen help prevent oxidation or combustion of the mercury inside the tube.

By changing the composition of the phosphor coating the manufacturer can change the color temperature of the light emitted by the tube. To start the lamp, a high voltage surge is needed to establish an arc in the mercury vapor between the lamp filaments at each end of the lamp tube. Those filaments remain hot as long as the tube is lit or "on". The flow of electrons between the lamp filaments excites the electrons in atoms of mercury inside the tube, causing them to emit radiant energy in the form of UV ultraviolet light.

The high start-up voltage, at V, is supplied by an electrical transformer or ballast in the light fixture. Once the lamp is started, the gas offers a decreasing amount of resistance, which means that current must be regulated to match this drop.

Once the lamp is operating, voltage drops to a much lower level, usually around 93V for tubes under 30 Watts, or from V for tubes at 30 Watts or more. Our sketch above illustrates the basics of how a fluorescent lamp works. When the circuit supplying the lamp is switched ON current passes first through the ballast, then across the filaments at one end of the lamp, following the path of least resistance through the starter switch and on through the filaments at the other end of the lamp.

Current flowing through the starter, itself filled with neon or a similar gas, causes an arc between the two contacts in the starter, essentially closing the circuit across the starter switch to permit a high initial voltage to flow to the lamp filaments causing them to heat up, boiling electrons off of the filament surface, ionizing the gas inside the tube or lamp and causing it to light.

As current continues to flow through the starter, a bimetallic strip in the starter heats, curves to close a metal-to-metal contact, stopping the arc inside the starter as current now flows through the metal contacts. Stopping the arc inside the starter allows its bimetallic strip to cool, opening the starter circuit.

Because current is now flowing through the ionized gas inside the fluorescent lamp the starter is no longer needed. However, when fluorescent bulbs flicker, the situation is more than just a minor annoyance. If your fluorescent lights flicker, you should fix the problem immediately because flickering can cause the ballast to overheat or fail.

We offer electrical services in Northern Virginia , and we can help you if your fluorescent bulbs flicker. If your fluorescent bulbs flicker, most likely the problem is with the bulb itself. If the bulb is very dark on either end, it may be defective and burned out. The best way to test the functionality of a bulb is to put it into a fixture you know works.

The problem could be with the starter in your bulb, but most new bulbs do not have starters. However, if your bulb has a starter, you should be able to see it at the bottom of the bulb!

Fluorescent bulb starters generally look like gray metallic cylinders and require a simple replacement! Stack Overflow for Teams — Collaborate and share knowledge with a private group.

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Asked 5 years ago. Active 2 months ago. Viewed 3k times. Thanks for your answers in advance. Improve this question. Jon Jon 57 1 1 gold badge 4 4 silver badges 9 9 bronze badges. When replacing one lamp always replace both. When buying bulbs try to get them out if a case, rather than singles that may have been abused. T12's have two pins on each end, watch out for pin damage, with damaged pins bulb life can be shortened.

Watch bulb installation with T12 bi-pins it's possible to get one end of the bulb in with a pin hanging outside the socket, the bulb may still light, but it's like pin damage and may shorten bulb life.

Finally if you're seeing a burned end on a relatively new bulb the bulb may have been damaged internally by rough handling before you got it. Add a comment. Active Oldest Votes. Improve this answer.