Which of the following is NOT a characteristic of extra low voltage?

Extra low voltage (ELV) systems are defined by specific voltage limits that determine their safety and application uses. The key characteristic of extra low voltage is that it does not exceed 50 volts AC—this is a fundamental principle established to ensure safety and reduce the risk of electric shock. Therefore, stating that extra low voltage exceeds 50V AC is incorrect.

The other characteristics associated with extra low voltage include being safe to touch and significantly reducing the risk of electric shock. This is because the low voltage levels are less likely to overcome the body's natural resistance to electrical current, making them safer around users. Additionally, extra low voltage is widely used in various applications, from low-powered lighting to telecommunications, due to its inherent safety features.

Thus, the correct statement is that extra low voltage exceeding 50V AC is not a characteristic of ELV; it correctly identifies what distinguishes ELV from higher voltage systems.