Question 578Electricity/Electronics - Assistant Engineer70% to pass
On a steamship, if No.1 SSTG fails to produce a voltage while in the automatic voltage control mode, but successfully produces a voltage while in the manual control mode, what statement is true?
AI Explanation
A) The voltage failure would most likely be the result of a failed voltage regulator.
This is the correct answer. In an automatic voltage control mode, the voltage regulator is responsible for maintaining the generator's output voltage at the desired level. If the No.1 SSTG (Ship's Service Turbine Generator) fails to produce a voltage in this mode, the most likely cause is a failure in the voltage regulator. However, the generator can still produce a voltage when switched to manual control mode, indicating that the generator itself and its other components are functioning properly.
The other options are incorrect because they do not adequately explain the specific symptoms described in the question. A failed exciter generator or an open field winding would likely prevent the generator from producing any voltage, even in manual control mode. An open manual rheostat would not specifically cause a failure in the automatic voltage control mode.
Related Questions
#576 If the cooling water system is isolated for repairs, but it is still desirable to run the alternator pictured in figure "A" of the illustration, what must be done? Illustration EL-0037 #577 If a shipboard AC generator experiences a failure to produce a voltage, what may be the cause? #579 No.1 SSDG was operating in parallel with No.2 SSDG in supplying the 480 VAC main bus while sharing the electrical load evenly. As a result of a problem, if No.1 SSDG begins to motorize, but the generator has not yet tripped out by the action of the reverse power relay, what would be the indication of this? #580 How can the loss of residual magnetism in an alternator or generator be corrected?