By what means is the frequency of an...

🔍 Key Concepts

• Relationship between prime mover speed (engine or turbine) and AC frequency • Difference between measuring instruments (indicate frequency or phase) and control devices (actually change speed/load/voltage) • How the ship’s main engine/generator governor affects generator output characteristics

💭 Think About

• Which component on a main switchboard is used to actually CHANGE the alternator’s output frequency, not just display it? • What variable must be changed to alter AC frequency: voltage, speed, or phase angle? Which device controls that variable? • On a generator panel, which control is adjusted when matching frequency before paralleling two generators?

✅ Before You Answer

• Identify which options are indicating instruments only versus true control mechanisms • Recall that AC frequency is directly tied to rotational speed and number of poles, and only one of these options can change speed in normal operation • Think about which control you physically move when bringing another generator on the board and matching its frequency

By what means is the frequency of an alternator adjusted from the main switchboard?

frequency meter

voltage regulator

governor control

synchroscope switch