QA

Quick Answer: How To Check Fluorescent Light Ballast

How can you tell if a fluorescent light ballast is bad?

If your fluorescent lighting is displaying any of the signs below, it could be a symptom of a bad ballast: Flickering. Buzzing. Delayed start. Low output. Inconsistent lighting levels. Switch to an electronic ballast, keep lamp. Switch to an electronic ballast, switch to a T8 fluorescent.

How do I test a ballast with a 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.

How do you check for a bad ballast?

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.

How do I know if my ballast is T8 or T12?

If no markings are available, the size in diameter of the tube is the easiest way to determine the type you have installed. T8 tubes are 1-inch in diameter and T12 tubes are 1 1/2 -inch.

Why do new fluorescent lights flicker?

Lamp blinks: This is usually because of a poor connection where the tube fits into its sockets at each end. Take the tube out and clean the pins at each end with fine steel wool. Brush dust out of sockets, then reseat firmly.

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.

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 output of a fluorescent ballast?

Fluorescent lamps use a ballast which transforms line voltage to a voltage to start up and operate the lamp(s). Newer fluorescent ballasts are usually rated for both 120 volts and 277 volts. Some are rated for only 120 volts, others for only 277 volts (used in commercial environments).

How can you tell if a ballast is good?

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.

How long do ballasts 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.

How do you test 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.

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.

Can I use T8 in place of T12?

T8 tubes are simply 1 inch in diameter versus the 1.5 inch diameter of T12 tubes. In an effort to make LED tube lights compatible with the internal dimensions of most fixtures, you will find that most LED tube lights feature a T8 or 1 inch diameter. They can indeed be used in T12 fixtures.

How do you read a ballast number?

The T stands for tubular and the number provides the diameter in 1/8 of an inch. Lamp diameter is determined by ballast type. Therefore, a T12 ballast must use a T12 bulb. A T5 ballast must use a T5 bulb and so forth.

How can you tell if a ballast is magnetic or electronic?

Stand under the light or a place close to the light and point your cell phone camera at the light. If you can see some strong dark strips flickering in your camera, it must be a magnetic ballast based light. Otherwise it should be an electronic ballast based light.

How do you stop fluorescent lights from flickering?

at FLUORESCENT LIGHT FIXTURE BULB / BALLAST DISPOSAL. A bad starter in the fixture – try replacing the starter. A bad ballast in the fixture. Replacing a bad magnetic ballast with an electronic ballast can remove problems of flickering fluorescent light and will lower the operating cost of the fixture.