Wiring an electrical receptacle incorrectly can lead to overheating and possibly a fire.
The higher the electrical load placed on an electrical outlet, the importance for a correct and solid connection becomes more important.
Obviously, it is ALWAYS important to wire an outlet correctly, but what is correct?
Most standard electrical outlets offer two ways to connect the wires.
The first method to connect the electrical wiring to an electric receptacle is via the screws for the hot, the neutral and the ground.
The second method to connect electrical wiring to an electrical receptacle is via the holes with the push in connection.
The push in connection is never recommended, as it leads to a loose connection, which leads to heating, and possibly a fire.
Here is an example of an outlet I recently replaced. This outlet was used to power a small AC window unit in the summer, and a small space heater during the winter. Also, a regular standing lamp. The reason for even opening up this outlet was to replace the single outlet with a dual outlet box, dual receptacles. This will provide 4 outlets, and the cords for the AC Unit and the heater will not have to be swapped. Both cords could not be connected at the same time, and in Texas the weather switches all over the place.
The owner has debilitating rheumatoid arthritis and is not capable of switching the power cords.
Notice the dark area on the back of the receptacle. This area has heated up an excessive amount. It’s a good thing this outlet was replaced.
The main issue with the push in connection method, is too little contact area.
The metal touching the electrical wire is thin, and doesn’t provide enough surface contact – and thus overheats.
As the outlet is used, heats up, then cools down, eventually the connection becomes weaker, and leads to an even looser connection, which leads to more heat.
The proper way, in my opinion, is to use the provided screws to make sure that the connection is extremely tight, and has plenty of surface contact area for a solid, very low resistance connection.
If you are interested in some additional reading: