Coming-in speed is defined as which of the following?

• A. RPM for proper output voltage
• B. Minimum speed a generator has to turn to produce full volts
• C. Maximum speed before saturation
• D. Speed corresponding to rated current

Answer: (B)

Coming-in speed is the minimum speed at which a generator will produce its rated voltage. As the rotor speeds up, the generated voltage rises, and once you reach this speed, the output reaches its full (rated) voltage with the excitation applied. Below this speed, the voltage is lower than the required level. This concept is about voltage onset, not the current the load draws or the point of magnetic saturation.