Two paralleled alternators are operating...

Two paralleled alternators are operating...

Question 1 of 270705eccefa4bacbc34ba4d481ac

Two paralleled alternators are operating near rated load. If one trips out mechanically resulting in a reverse power trip, which of the listed actions should be taken FIRST?

Question 1 of 27070

Q

Two paralleled alternators are operating near rated load. If one trips out mechanically resulting in a reverse power trip, which of the listed actions should be taken FIRST?

🔍 Key Concepts

• Ship service generators and bus ties when alternators are operating in parallel • Purpose of a reverse power trip and what it protects • Difference between ship’s service generators and the emergency generator / emergency switchboard

💭 Think About

• When one of two paralleled generators trips mechanically, what immediately happens to the load that both were sharing? • In that instant, which action is needed first: protect equipment, restore lost generation, or change how loads are connected? • Under normal design, when does the emergency generator start and when are vital loads transferred to the emergency bus?

✅ Before You Answer

• Identify which generator/switchboard actually lost power: the main bus, the emergency bus, or just one machine feeding the main bus • Confirm what the reverse power relay is trying to prevent and whether restarting that machine instantly is safe • Recall under SOLAS/USCG rules that the emergency generator and emergency bus are automatically started/connected only after a total or specified loss of main source of power, not just loss of one of several paralleled units