🔍 Key Concepts

• Shipboard electrical systems: voltage, frequency, and phase sequence • Compatibility between shore power and ship’s generators • What must match exactly vs. what can have acceptable tolerances

💭 Think About

• Which of these factors (voltage, frequency, phase sequence, total kW capacity) is most critical to prevent motors from turning the wrong way or serious equipment damage? • Can a ship safely operate if shore power voltage or frequency is slightly off nominal, within limits, but something else is mismatched? • Does shore power need to supply the ship’s maximum generator capacity, or just the expected load while in drydock?

✅ Before You Answer

• Identify which parameter, if reversed or mismatched, can cause immediate damage to rotating machinery (like pumps and winches) • Recall that three-phase systems have not just voltage and frequency, but also a specific phase rotation/sequence • Consider whether being in drydock typically requires using the full generator capacity or only a portion of it