Plugging an extension cord into itself is not recommended and can lead to potentially dangerous consequences. When you connect both ends of the extension cord together, you are creating a short circuit.
A short circuit occurs when the current flows through an unintended path with very low resistance, bypassing the normal load. This can lead to a significant increase in electrical current, generating excess heat and potentially causing the following:
Fire hazard: The excess current can cause the extension cord to overheat and potentially catch fire. This can not only damage the cord itself but also pose a serious fire hazard to the surrounding area.
Damage to electrical equipment: If you have any devices or appliances connected to the extension cord, the sudden increase in current can damage them due to the higher-than-expected voltage.
Damage to electrical system: The short circuit can overload the electrical circuit in your home or building, leading to damage to the electrical system or even tripping the circuit breaker.
Electrocution risk: There is also a risk of electrocution, as you are creating an unsafe electrical connection.
In summary, plugging an extension cord into itself is a dangerous practice and should be avoided at all costs. Always use extension cords as intended – to extend the reach of a power source to safely power appliances and devices. If you need a longer cord, consider using a single, appropriate length extension cord rather than connecting multiple cords together.