What potential issue arises when an electromechanical lock is powered by AC?

When an electromechanical lock is powered by alternating current (AC), one of the most noticeable issues is that the lock may make a buzzing sound. This is primarily due to the nature of AC power, which causes the electromagnetic components within the lock to rapidly attract and release. The continuous fluctuation in polarity can create vibrations that lead to an audible buzzing or humming noise.

This sound is not only a sign of the electromechanical lock's operation but can also indicate that the lock is functioning in a manner not typically designed for, such as experiencing unnecessary stress or strain on its components. While potentially a nuisance, it does not necessarily imply that the lock is non-functional.

In considering the other options, the potential for the lock to become stuck or wear out faster involves issues related more to design rather than the effects of AC power specifically. While excessive power consumption can occur in poorly designed systems, it is not a standard issue associated directly with AC in this context.