They don't typically do, but keep this in mind...
A coiled extension cord can potentially trip a circuit breaker due to the increased resistance and heat generated when the cord is tightly wound. When electrical current flows through a conductor, it encounters resistance, which causes the conductor to heat up. In a coiled extension cord, the winding creates additional resistance, leading to a higher concentration of heat in certain areas.
The increased resistance and heat can result in an overcurrent situation, where the current surpasses the designed capacity of the circuit. Circuit breakers are designed to protect the electrical system from such overcurrents by tripping and interrupting the flow of electricity.
On the other hand, when an extension cord is uncoiled and laid out properly, the resistance is distributed more evenly, and there is better heat dissipation. This reduces the likelihood of overcurrent and minimizes the risk of tripping the circuit breaker.
In summary, coiling an extension cord can create hot spots and increase resistance, leading to potential overcurrent situations that may trip the circuit breaker, while an uncoiled extension cord allows for better heat dissipation and reduces the risk of overloading the circuit.