Question 315Electricity & Electronics - Assistant Engineer

The correct answer is A) There may be insufficient current to energize the trouble relay coil and to open the contacts to silence the alarm. This is because the trouble alarm circuit is designed to detect a failure or burnout of the primary port running light. When the primary light (port running light "1") burns out, the lower current draw triggers the trouble relay to sound the alarm and illuminate the trouble lamp. Replacing the primary light with a lower wattage bulb may not draw enough current to properly energize the trouble relay coil, preventing the contacts from opening to silence the alarm. The other answer choices are incorrect because: B) The new lower wattage light may not immediately burn out, but the insufficient current will prevent the trouble alarm from clearing. C) The trouble buzzer voltage is not dependent on the port running light wattage. D) The trouble relay coil will not overheat due to the lower wattage of the replacement light.