Synchronization – Synchroscope Interpretation. Marine Engineering Function 2 Electrical, Electronic and Control Engineering.
Exam Scenario. During synchronization, the synchroscope rotates rapidly clockwise. What does this indicate?.
Choices. A. Incoming generator frequency is lower B. Incoming generator frequency is higher C. Voltage is too low D. Phase sequence is incorrect.
Correct Answer. B. Incoming generator frequency is higher.
Key Concept. Synchroscope shows frequency difference between incoming and running generator. Direction of rotation indicates whether incoming generator is faster or slower..
Clockwise Rotation Meaning. Clockwise rotation = Incoming generator frequency is HIGHER than busbar frequency. The generator is running faster..
Counterclockwise Rotation. Counterclockwise rotation = Incoming generator frequency is LOWER. The generator is running slower..
Speed vs Frequency. Generator frequency depends on speed: Higher speed → Higher frequency Lower speed → Lower frequency.
What To Do Onboard. If rotating clockwise (too fast): - Reduce prime mover speed If rotating counterclockwise (too slow): - Increase speed Goal: Stop needle at 12 o’clock before closing breaker.
Common Exam Trap. Clockwise = Faster Counterclockwise = Slower Do NOT confuse with voltage or phase sequence.
Quick Recall. Clockwise = FAST Counterclockwise = SLOW.