In the United States, how many times does AC voltage reach a positive peak in one second?

In the United States, the standard alternating current (AC) frequency is 60 hertz (Hz). This means that the AC voltage completes one full cycle – which includes going from a positive peak to a negative peak and back to a positive peak – 60 times in one second. During each cycle, the voltage reaches its positive peak once. Therefore, in one second, it reaches a positive peak 60 times.

This frequency is standardized to ensure compatibility of electrical systems and equipment across the country and to provide consistency in the operation of electrical devices. Understanding this frequency is essential for electrical contractors, as it affects device selection, circuit design, and overall system performance.