What causes the blue spark that you see is the split second where the electrical plug and socket are close enough together that the electrical current literally jumps across the gap. This is what causes the spark and it actually happens every time you plug something in. It is completely safe and normal.
The short answer is that sparks are blue because of the colors given off from nitrogen and oxygen when they are excited. Essentially, light goes in, but doesn't come out (like thunder dome). When light goes in, it reflects off the surface but some of it gets absorbed. Each time it reflects, some gets absorbed.
Gaps like these can occur when you're just about to plug in a device or when you've just unplugged it. For a split second, the prongs are close enough for the electrical current to reach, and when it makes that “jump” or “arc,” you'll see a small, brief spark. This is normal and not cause for concern.
We generally operate our appliances on . When a gap less that the above distance occur between the terminals of a key when we switch off a sudden dielectric breakdown of air molecules occur. This results in conduction of air molecules for a short duration and during that period of time we see spark.
When something is plugged in, or turned on, some of that very fast, hot electricity transfers from the outlet into the appliance, light, computer or whatever. A rapid draw on available power occurs, resulting in a brief spark. This is normal and no more threatening than a mini-jolt of static electricity.
Normal Spark
Electricity runs along circuits and back to the main grid without interruption. When a device is plugged into the outlet, some of the electricity transfers from the outlet to the device. When you unplug it, you're breaking the electric contact, causing the spark.
The most common signs of bad spark plugs include start-up trouble, rough idling, sluggish acceleration, declining fuel economy, engine misfiring, and engine knocking.
An ignition system in good condition should have a blue spark and make a crisp snapping sound. If the spark is yellow or does not spark in a definite pattern, try to get a better ground and attempt this test again.
A normal spark plug will have brown or grayish-tan deposits on the side electrode.
Dark red-orange sparks are known from charcoal, iron powder leads to yellow/golden sparks, and hot burning elemental metal powders such as aluminum and titanium can form bright white sparks. The color of sparks is dominated by black body radiation.
One of the most obvious dangers of sparking outlets is that they present a fire hazard. If there are uncontrolled sparks coming from an outlet, it's possible that it could ignite something nearby and cause a house fire.
Most electrical fires are caused by faulty electrical outlets and old, outdated appliances. Other fires are started by faults in appliance cords, receptacles and switches.
Faulty electrical outlets, obsolete wiring, outdated appliances, or faulty receptacles and switches can result in fire. There is an increased risk of accidents when homeowners avoid performing routine maintenance and scheduling safety checks with a certified electrician.
Ordinary electrical sparks are always a pale blue color. If the sparks you're seeing are yellow or white, it could mean trouble. Sparks accompanied by a burning smell. A burning odor is often a symptom of a hot outlet, which can quickly become a fire hazard.
Q: Does Blue Sparks do any damage when cast on people? A: It only hurts a little.
The electrons in each air atom obtain energy from the electricity and become aggravated or excited. As the electrons return to their former or original energy level, they release a photon of light. Henceforth, it looks as if electricity is blue in color.
Spark color determines ignition coil performance. A spark-ignition engine is an internal combustion engine, generally a petrol engine, where the combustion process of the air-fuel mixture is ignited by y a spark from a spark plug. A bright blue spark is best. A yellow/orange spark signifies weak ignition.
The strength of the spark is revealed in the color. A red or yellow spark is weak and probably will not spark in the cylinder. A blue or white spark is strong and has enough voltage to fight across the spark plug gap even under pressure within the cylinder.
Black spark plugs are a sign of a weak spark or too much fuel in the air-fuel mixture.
A good spark will be blue-white and will be plainly visible in daylight. If a good spark is present, the problem is probably not in the ignition system. Check the fuel system and/or stark timing. Weak sparks are orange or red and may be hard to see in daylight.
Make sure the spark is strong and blue in color. If the spark is weak and dull orange, it's likely that it's not strong enough to ignite the engine's air and fuel mixture. (Optional) if There Is No Spark, Connect a New or Known Working Plug Connect a good plug to the coil pack or spark plug wire and repeat the test.
Spark Color
From this we can see that harder metals, ones which require more energy to separate, will produce sparks with smaller energies, and a duller, redder color. While steels that are softer, like mild steel, will produce sparks that are white.
Engine has a rough idle
If your Spark Plugs are failing your engine will sound rough and jittery when running at idle. This can cause vibrations to resonate through the vehicle which could cause further costly damage.
Ordinary copper and nickel spark plugs should be changed every 30,000 to 50,000 miles, unless otherwise suggested by the spark plug manufacturer. Platinum and iridium spark plugs tend to last longer than standard copper and nickel spark plugs. Expect to change them every 60,000 to 150,000 miles unless otherwise noted.