QA

How To Check A Ballast

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

If the ballast is bad, the needle on the multimeter will not move. If the ballast is still good, the needle should sweep to the right across the face of the multimeter. Install a new ballast, if necessary. Replace the ballast cover on the fluorescent light fixture.

How do you tell if it’s the ballast or the bulb?

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 are my fluorescent lights flickering?

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. Flickering fluorescent lights can also be a result of temperature.

What does a bad ballast smell like?

A common source of these odors is the fluorescent light ballast. When called to such an incident, you typically will find an electrical odor or a haze of smoke. Overheating ballasts often exhibit symptoms. They may cause the bulb to flicker, shine, dim, or not work at all.

What is the voltage output of a 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).

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.

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.

What happens if you wire a ballast wrong?

The ballast is wired to the home’s hot, neutral and ground wires on one end, and to the light fixture’s lamp holders on the other end. If a ballast fails, it can cause a short, burn out tubes or even cause a fire, so it must be replaced.

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 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.

Do all fluorescent lights have a ballast?

All fluorescent bulbs require a ballast. All compact fluorescent (CFL) bulbs require a ballast, which is often integrated. All HID bulbs require a ballast, which is sometimes integrated. No LED bulbs require a ballast, although some are engineered to work with an existing ballast.

How do you fix a flickering fluorescent light bulb?

Brush dust out of sockets, then reseat firmly. If the tube still blinks when the light is turned on, wiggle it a few times while the light is on to see if this cures the problem. If not, take the tube out and inspect sockets closely to see if spring contacts are bent or corroded.

Can fluorescent lights explode?

Technically, they don’t EXPLODE, they IMPLODE. When a fragile, mainly hollow vessel has a near-vacuum inside and some external force (e.g. a hammer) causes the vessel (in this case, a fluorescent light bulb) to become broken, air rushes in to fill the near-vacuum.

Can a bad ballast cause a fire?

As with any electrical situation where overheating is possible, a bad ballast can pose a fire danger. The overheated ballast could cause the plastic housing on the light itself to melt and, in the right conditions, flame up.

Do fluorescent bulbs smell when they burn out?

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. In fact, popping and smoke means that the bulb’s end-of-life mechanism worked correctly. For safety’s sake, do check the CFL packaging before buying.

Why would a ballast melt?

Incorrect Bulbs When a bulb of the wrong size or voltage is used in the fixture, the ballast often overheats, causing the light to shut off. The bulbs and the fixture must also match in frequency, or the ballast becomes overworked and overheated.