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Can You Change A Light Bulb With The Power On?

So you have a dead light bulb in your socket, and you are just about to change it but don’t know if the switch is on or off?

Maybe common sense prevents you from going ahead!

Rightly so!

Changing a light bulb while the power is still on can be dangerous. The light bulb may burst, and there is a risk of getting an electric shock if you accidentally touch the socket!

Want to know how?

The following topics are definitely worth the read!

What Happens If You Don’t Turn The Power Off When Changing A Bulb?

It makes the most sense to turn off the power and then change your light bulb. But what if your bulb has blown out, and now you cannot remember if you turned the switch off?

Incandescent filaments heat up to 2550°C, but the bulb’s surface is usually 250°C. So if you touch it, you will naturally burn your fingers.

Even if you use a towel, the bulb could burst.

Though LEDs and CFLs don’t heat up nearly as much, it is rather hot for human standards, and you should change them only after you switch the power off.

Fluorescent bulbs can burst if you try to change them with the power still on. They are fragile, and your cold hands against the hot bulb can cause it to explode.

The best way to change a light bulb is to turn the power completely off. When I say completely, I mean to turn off the circuit breaker in the fuse box.

Only switching the light switch off is not enough. If the switch is wired incorrectly, the positive will still be carrying current to the holder.

So, if your hand comes in contact with the holder, you will get a shock.

Once the power is completely off, I recommend waiting for a few minutes for the bulb to cool off because the bulb is still hot to handle.

Let’s be honest, fatal accidents are happening and in extreme scenarios can lead to lethal consequences, but this is not today’s topic.

Now let’s take a look at whether you can change fixtures if the power is on!

Can You Change A Light Fixture With The Power On?

incandescent fixture

In short, yes, however, this would be a significant risk to take even if you turn it off at the switch!

Since you will be handling wiring to the fixture, the positive wire going to the light fixture could be dead, but the neutral can still be live.

The neutral can carry close to 240 volts under certain circumstances, such as if the wiring in your house has been done incorrectly, or if the earthing in your home is old and hasn’t been serviced recently.

But if it is well connected, a live neutral is usually a ground wire.

The dangers associated with disconnecting a live, neutral range from voltage fictionalizations can damage devices that are plugged in to shock hazards.

If there are un-switched live connections in the box or the switch is on the wrong leg, this could lead to a hazardous situation.

Sometimes circuits are “backfed” by other circuits, and if you try to change the light fixture, it could cause problems. You need to find the breaker or fuse and switch it off before attempting to change the fixture.

To be absolutely sure, after you turn the breaker off, use a VOM (Volt-Ohm-Milliameter) to check if there is any power.

The multimeter has plug-in test leads, which may either have probes at both ends or a single probe on one end and an alligator clip at the other end.

Use the switch or the adjustment knob to measure the current, which will usually be in ohms. The dial will indicate how much current is flowing, or if there is any current at all.

The steps involved in replacing a fixture are pretty much the same, be it a ceiling-mounted fixture or a wall-mounted sconce.

The power source to the fixture definitely needs to be shut down and if that can’t be figured out, turn off the electricity for the whole house.

The dangers of changing a light fixture with the power source on are significant, so please avoid it where you can.

What Are The Hazards Of Screwing In A Light Bulb In A Live Socket?

You will most likely burn your fingers if you use incandescents as they get heated very quickly and are connected to a live wire.

If you have a metal-bodied lamp that is not grounded and the wires are frayed, then there’s every chance that the live wire is touching the body, and you could get a shock just by touching it.

Another possibility is that the glass and metal shell can separate, resulting in a bang and splatter of molten metal.

Or, if the socket is wired backward, it is easier to touch the fatal voltage.

In this case, instead of the tip of the socket being hot, the shell will be hot, and if you touch the shell of the bulb while you are standing on a wet concrete floor barefoot, you will get a resounding shock.

Another instance could be when the bulb base’s solder pads have developed dimples, which causes the rotation to be difficult.

If you try and press harder or deeper to release the bayonet, the glass will shatter. And you will risk coming into contact with the bare filament supports.

If the filaments come in contact with one another, they will cause a short circuit, and you will burn your hand.

Another danger is when you stand on a ladder, stool, or concrete floor and try and fix a light bulb in a live socket.

If there are any loose wires, they can contact the metal holding of the bulb, which can result in a shock.

I do not recommend using aluminum ladders when doing electrical work, as metal is a good electricity conductor. Try to use a wooden ladder.

Another case could be when the socket wires may turn along with the bulb and cause a short circuit.

It only takes a tiny spark to cause a fire, especially if there is any flammable material near the fixture.

In three-way lamp circuits wired in an obsolete way, the circuit’s shell can be hot.

If the insulating paper has deteriorated, it can short out to the outer brass shell, resulting in a bang and molten metal.

Final Words.

It’s always better to be safe than sorry! I would caution you to switch off the power if you need to test a bulb, change a bulb, replace a fixture, or screw in a lightbulb.

What’s a little extra effort when it could actually cost you your life?!

Have you ever tried to change the light bulb with the power on yourself?

Did you manage to do it successfully?

Share your story in the comments below.

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