What causes an electrical outlet to spark

Because of safety risks involved, it's best to let a trusted electrician take care of sparking outlets. (Photo by Katie Jacewicz)

Because of safety risks involved, it's best to let a trusted electrician take care of sparking outlets. (Photo by Katie Jacewicz)

It can be frightening when an electrical outlet sparks. Sometimes it’s normal, and sometimes it’s an indicator that there is something wrong with the outlet. Here is what you need to know about electrical outlets, why they spark and when it’s time to call in a Los Angeles electrician.

The power in outlets
In the United States, the power running through outlets is fast and hot. It should easily flow through the available circuits in your home and back out to the main grid without being interrupted. The outlets in your home use this fast-moving current to provide you with the power you need. When an appliance is plugged in, some of the power moves into the appliance to be used.

Normal sparks
When that power is suddenly diverted to an appliance, there will be a quick draw on the available power, causing a brief spark. Once the electrons are flowing freely, there should be no reason for a spark to form. This is normal, and it’s comparable to static electricity.

Short circuits
If too much heat builds up in an outlet, it can actually melt the insulation that surrounds the wires. As the wires become exposed, the chance for an electrical fire increases. When a connection is made, the electrons can leap to the wrong area and cause a serious spark. This is known as a short circuit and can actually case an electrical fire.

Water can quickly cause an outlet to spark and short out. Installation of a special outlet known as a ground fault interrupter (GFI) will cause the circuit to shut down rather than starting a fire.

Outlets gradually wear out over time. As the years pass, the connections will gradually loosen, increasing the chances that a short circuit will occur and start a fire. Appliance cords that are old and worn can also cause an outlet to spark.

Poor repairs
When people decide to fix an outlet themselves, it’s important that they know exactly what they are doing. When people try to take short-cuts to fix electrical problems, they often create far more dangerous situations that can result in fires.

Repairing faulty outlets
If an outlet sparks briefly once in a while, then it’s probably normal and safe. When an outlet sparks every time you plug something in, you probably have a problem on your hands. Replacing an outlet is not a difficult job, but if you suspect a problem it should be left to the professionals. Installing a GFI in a line can be tricky and can cause problems for items further down the line if not done properly.

To avoid creating hazardous situations, call a Los Angeles electrician. During 2010, Angie’s List helped provide information about highly rated service providers more than 10,000 times when members searched the List or called the call center. The peace of mind that comes with knowing the job is done right will be priceless and your home will be safer.


The information I found was very helpful.

The most dangerous thing about electricity is usually the advice from a want-to-be electrician who is not sure what end of the cord plugs into the wall outlet. I can't believe that sparky would think its normal to have a wall outlet doing this? I could see if it was the 4th of July, and did it, but not every day? It should never spark. Get a insulated screw driver and tighten ALL connections, including neutral and ground wires on that circuit. KJ.

GFI ' S do not prevent fires they prevent you from getting electrocuted while around water.

I am a electrical engineer / electrician your comments on here are not to clear. I got news for you permalink it is not normal for any outlet to get warm got it. You are another dangerous person giving out advise with some knowledge.If the draw is to high your over current device in the load center will trip or a fire is possible. Loose connections are most seen because people who install them stab in the back of the outlet. the spring tension gives away due to heat . The outlets are cheap garbage.If you have any electrical problems get the proper help. It could save your life.

Randy is right. I spent 40 years in the trade. First of all ,sparks are never good, they are at temperatures high enough to start fires with any material and should always be avoided. If you are unplugging devices under load (while turned on) , you have a good chance of creating a momentary spark. This only damages the outlet if this practice continues. If an outlet sparks while it is used, stop using it immediately and call an electrician.

We found some old outlets in our church where part of the circuit was in the cover plate. This had deteriorated over time and gave a spectacular show until replaced. It had previously check out ok with a hand-held test unit. Other receptacles were wired wrong and were replaced when other electrical work was done.

Inductive kick is term sometimees used for spark caused by a collapse of the magnetic fields around the conductors. Similar to old autotransformer used in car ignitions giving "spark" across the spark plug providing 20K plus low current jolt. Similar to static discharge

I have generally found that most sparks and shorts are the result of a bad connection in the plug of the device itself. I have found very little problems with the outlet itself. Maybe my experience is rare, don't know. Gerry Hintlian

the pilot light went out, how to light it.

It's normal for a power plug to get warm if it is supplying current to a high-power appliance like a hair dryer, iron, or vacuum cleaner. Moreover, it's normal for a spark to appear at the outlet if the plug is pulled while the appliance is still on. But the outlet and plug should never become hot, or emit odors or smoke. If that happens, unplug your appliance and replace the wall outlet.

very common problem i run into a lot is too large of fuse for the size of the wire,replacing a fuse with a larger value fuse is asking for trouble.many people theorize that by putting in a larger fuse i stop the fuse from blowing,but in all actuallity they are actually doing more harm than good,a fuse keeps blowing over and over it is telling you something is wrong either with the wiring or the appliance you plugged in.or that circuit is simply overloaded.

When you take out a plug from a wall outlet it should be cold to cool at the pins. If hot it means the connection is poor or and the equipment plugged in is taking to much current. If you hear arcing or sparking and maybe see smell smoke or a fish like smell then the socket on the wall needs replacing. Maybe the plug on the equipment too. This state of affairs applies to all electrical equipment wherever it is. The cause is a lose connection or poor connection where the electricity is leaving the socket and travelling to the plugged in appliance at the socket/plug junction. If the current can not flow easily with little resistance, as when the connectors are lose or poor, the resistance will be a lot higher than it should be so heat is developed because the higher resistance causes the voltage to be lower than should be, at that point, so it manifests itself as heat. This is waste power, in watts, and this causes heating. Watts is power and is the voltage, say 120 V ac times amperes, say 5A ac which equals 120x5=600 Watts. The item is rated at 600 Watts, say a small iron for clothes. Note that 5 amps needs to flow through the iron AND through the wires in that circuit and the socket/plug junction. Normally the wires flowing eventually to that iron pass through the circuit wires that have a very low resistance so they drop (lose) very little voltage and the appliance gets a pretty full 120 volts. If however there is a lose/poor connection like at our socket/plug junction that will have appreciable resistance. This will oppose the current flow to the appliance. This will lower the applied voltage and so less power will arrive at the appliance. BUT because of this higher than should be resistance which loses some voltage but still has current flowing to the appliance it means that the socket/plub junction is lower the voltage and lessening the normal current. Where ever you got a voltage drop and a current flow you USE power. So the junction heats up.

Some electricians and Home Inspectors may use a Circuit Analyzer that will identify issues with outlets. These devices will identify abnormal voltage drops at each outlet to alert you of potential hidden problems. Large voltage drops at an outlet along with a power hungry device plugged in are all you need for a fire. As a Home Inspector I use this on every home inspection for the safety of my clients.

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