How do you tell if a fluorescent bulb or ballast is bad?

If your fluorescent lighting is displaying any of the signs below, it could be a symptom of a bad ballast:

  1. Flickering. …
  2. Buzzing. …
  3. Delayed start. …
  4. Low output. …
  5. Inconsistent lighting levels. …
  6. Switch to an electronic ballast, keep lamp. …
  7. Switch to an electronic ballast, switch to a T8 fluorescent.

What happens when a ballast goes bad in a fluorescent light?





When your fluorescent light flickers or makes a loud and annoying hum, a degrading ballast is the cause. The ballast takes in electricity and then regulates current to the bulbs. A typical ballast will generally last about 20 years, but cold environments and bad bulbs can decrease this lifespan significantly.

How can you tell if the ballast is bad?

Depending on the ballast, you may have only red and blue wires. 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.

How long do ballasts last?

12 to 15 years

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 is working?





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.

Why are my fluorescent lights flickering?

Flickering fluorescent lights can also be a result of temperature. If the air around the bulb is cold and circulating, the bulb won’t be able to generate enough heat to work properly. The internal temperature of a fluorescent bulb should be about 50 degrees Fahrenheit for it to work properly and optimally.

Why do my fluorescent lights keep burning out?

There are many possible reasons why a light bulb burns out quickly: The power supply voltage may be too high. Bulbs may be loose or connected improperly. Excessive vibrations may be causing the filament to break.

Why do ballasts fail?

Ballast failure is often caused by the surrounding environment—mainly heat and moisture. When it’s too hot or too cold, a ballast can burn or fail to start your lamps. Heat, along with continuous condensation inside an electronic ballast, can cause corrosion over time.

How much does it cost to replace ballast?



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.

How do you change a ballast without turning off power?

Hold the ballast wire next to this wire with the stripped ends parallel but not touching. Quickly slip on the wire nut and screw onto the ends. (If the wire sparks, it will be inside of the wire nut.) Repeat this step with the other power wire.

Can you replace fluorescent bulbs while on?

Replacing the Bulb. Make sure that the power is switched off. Before replacing a fluorescent light, you should make sure the fixture is not powered on.

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.

Can you put fluorescent bulbs in backwards?

You can turn it either way but you want the LED’s to be facing out so it depends which orientation you install the tube.

Are ballasts polarity sensitive?

If the lamp is fluroescent, it has a ballast. If you can get to that, the ballast should be marked with either the polarity or the usual black and white wires for hot and neutral. Polarity should not matter though, with AC power.

Do fluorescent lights go in a certain way?

In a fluorescent circuit, beginning at the left-hand prong of the plug, current goes through the ballast, through one of the lamp filaments, through the closed switch in the starter, through the other filament in the lamp, and out the right-hand prong of the plug.

Can you replace fluorescent tubes with LED?



Yes, you can replace fluorescent tubes with LED tubes or LED-integrated fixtures. If you just want to replace the bulbs, you can use plug-and-play, direct-wire, or hybrid LED tubes. Plug-and-play tubes are the easiest to install as they do not require any rewiring to the fixture.

Are fluorescent tubes being phased out?

The government has announced plans today (Wednesday 9 June) to end the sale of halogen light bulbs from this September, as part of the UK’s wider efforts to tackle climate change. Legislation being brought forward this month will also include the removal of fluorescent lights from shelves from September 2023.

Will ballast compatible LED tubes work without a ballast?

The T8 LED tube won’t work without the ballast, so you are forced to continue buying and replacing ballasts as long as you have an LED tube that is ONLY ballast dependent.