Under what circumstance would a hand-held...

Under what circumstance would a hand-held...

Question 1 of 270705eccefa3bacbc34ba4d47f90

Under what circumstance would a hand-held portable phase sequence indicator be used should the main switchboard mounted fixed phase sequence indicator be inoperative?

Question 1 of 27070

Q

Under what circumstance would a hand-held portable phase sequence indicator be used should the main switchboard mounted fixed phase sequence indicator be inoperative?

🔍 Key Concepts

• Phase sequence in a three-phase AC system and why it matters • When you must verify rotation direction of motors and generators before connecting power • Difference between internal equipment replacement vs. making or synchronizing external power connections

💭 Think About

• Which of these situations involves connecting one three-phase source to another three-phase system where rotation direction must be confirmed before closing a breaker? • In which option would an incorrect phase sequence most likely cause motors to run backward or serious system damage? • Which activities are largely mechanical/electronic replacements that don’t by themselves require checking the ship’s overall phase rotation at the main bus?:

✅ Before You Answer

• Identify which choices involve three-phase sources being connected together (or to the ship) rather than just replacing a component. • Ask: where would a wrong phase rotation immediately affect large motors, cargo gear, thrusters, or pumps when you energize the system? • Eliminate options that deal mainly with local equipment replacement that doesn’t change or verify the ship’s main bus phase sequence.