What is the mathematical formula for determining the frequency of an alternator?

The formula for determining the frequency of an alternator is correctly expressed as F = (S × P) ÷ 120. To understand why this is the correct representation, it's important to look at the components of the formula.

In this context, "F" represents the frequency in hertz, "S" stands for the synchronous speed of the alternator in revolutions per minute (RPM), and "P" denotes the number of poles in the alternator.

The derivation of this formula reflects the relationship between these variables. The synchronous speed (S) indicates how fast the alternator is rotating, while the number of poles (P) affects how often the magnetic field swings or alternates, directly impacting the output frequency. Specifically, the formula accounts for the fact that for each full rotation of the alternator, a certain number of cycles of alternating current is produced based on the number of poles. The division by 120 in the formula is a factor derived from the conversion between RPM to hertz, as there are 60 seconds in a minute and the factor of 2 accounts for the alternating nature of the current (two cycles per full rotation for AC systems).

This understanding connects the speed of the alternator and its pole count