Why does the socket spark when I plug something in?

Why a socket sparks when you plug something in

If the appliance is switched on, current starts to flow a split second before the pins fully touch the contacts in the socket (outlet), and a tiny arc jumps across. With powerful appliances such as a heater or an iron, that arc is easier to see. The Spanish Schuko socket behaves exactly like any other.

When it is normal and when it is not

Normal:

• One small, isolated spark from an appliance left switched on, with no trace on the socket or plug.

Not normal:

• Large or noisy sparks, or sparks every time you plug in.
• Black marks, melted plastic or a yellowed socket.
• A burning smell, a breaker tripping or a plug that wobbles in the socket.

The most common causes

1. Worn or loose socket contacts. Over the years the socket loses its grip, the plug does not sit tight and the arc repeats with every use. Each spark burns the contact a little more.
2. A damaged plug or appliance cable. Bent or blackened pins, or a cable pinched next to the plug.
3. A loose connection behind the socket. A terminal that is not tight heats up and crackles inside the wall.
4. A short circuit in the appliance. If the breaker trips as you plug in, the fault is usually in the appliance itself.
5. Overloaded power strips (regletas). Several powerful appliances on one strip heat up the wall socket.

What to do right now

• Switch the appliance off before plugging it in or out. If the sparking stops, it was the normal arc.
• If the socket is marked or smells of burning, stop using it and switch off that circuit’s breaker in the fuse box.
• Try the appliance in another socket. If it sparks everywhere, the problem is the appliance; if only in one, it is the socket.

What the repair costs

Replacing a damaged socket costs a guide price of about 25 euros per unit, or 40 to 50 euros as a repair, according to industry price guides. If there is burnt wiring behind it or a short circuit to trace, a simple repair runs from 50 to 100 euros.

When to call an electrician

Call if the sparks keep happening, if you see marks or smell burning, or if a breaker trips when you plug in. An electrician checks the socket, remakes the connections and checks the cable size. In Seville, Spain, our 24-hour emergency electrician handles burnt sockets and short circuits, and our handyman electrician service covers planned socket replacements.