What Are the Causes of a Shorted Out Electrical Outlet?

Determining the cause of an electrical short is important to correcting the problem. Unchecked electrical problems may cause electrical shock and home fires. If the electrical breaker for the outlet repetitively opens, there is most likely a short in the circuit. Leave the breaker in the off position while you try to track it down.

...
A shorted-out outlet may cause a fire.

What Is an Electrical Short?

An electrical short is caused when the hot wire comes in contact with the neutral or ground wire. This allows the electricity to travel through the circuit with almost no electrical impedance. A circuit with no impedance draws excessive current, which burns or melts the wires. A short can also be caused when the hot wire comes in contact with a metal electrical box. This is because the box is grounded to the earth, which completes the circuit.

Outlet Wiring

A 120-volt electrical outlet uses three wires to deliver the electricity safely. The black hot wire sends the power from the electrical panel to the outlet. The white neutral wire provides the path back to the source, which is necessary for electricity to work. The green or bare ground wire acts as the backup safety system. In the event of a short circuit, the ground wire provides a safe path back to the earth. This reduces the likelihood of a person being electrocuted.

Outlet Short Circuit

A short in an outlet is because one of the wires has come loose and the ground or neutral wires has made contact with the black hot wire. You can check this by first turning off the power at the electrical panel and double checking it is off. Remove the outlet cover to inspect the connections. If the electrical wires or terminals are burn or disconnected, the outlet needs to be replaced.

Other Possibilities

It is common that the outlet itself is not the source or the short. A short can occur at any electrical connection in the entire circuit. This would affect the power supply to the outlet because its circuit would be interrupted. Finding a short requires some trial and error. An electrician would typically start at the power source, then work his way along the wires, looking closely at each connection.