As shown in the illustration of a vessels navigational lighting circuit, if port running light "1" burns out, the trouble buzzer will sound and the port running light trouble lamp will illuminate. Switching to port running light "2" clears the alarm. If port running light "1" is replaced with a light of a smaller wattage and the circuit is switched back to port running light "1", which of the following is true? EL-0058

Correct Answer: Option A — There may be insufficient current to energize the trouble relay coil and to open the contacts to silence the alarm.

Navigational light monitoring circuits rely on current flow through a sensing relay coil. Reducing the wattage decreases total circuit current below the relay pickup threshold, preventing the coil from energizing sufficiently to open contacts and silence the navigation light alarm.