Question 247Electricity/Electronics - Assistant Engineer70% to pass
You are in the planning stages of setting the longtime overcurrent trip of a ship's service generator circuit breaker. According to 46 CFR, Subchapter J (Electrical Engineering), what statement is true regarding the criteria for the longtime overcurrent trip setpoint, assuming the generator is capable of being paralleled?
AI Explanation
The correct answer is B) The trip point should not be larger than 115% of the generator rating for a continuous rated machine.
This is based on the requirements in 46 CFR Subchapter J, Section 111.12-1(b), which states that the longtime overcurrent trip setting for a generator circuit breaker should not exceed 115% of the generator's continuous rating. This ensures that the circuit breaker will trip before the generator is overloaded and potentially damaged.
The other options are incorrect because A) and C) set the trip point too low, which could allow the generator to be overloaded, while D) sets the trip point too high, which may not provide adequate protection for the generator.
Related Questions
#245 You are in the planning stages of setting the instantaneous trip of a ship's service generator circuit breaker. According to 46 CFR, Subchapter J (Electrical Engineering), what statement is true regarding the criteria for the instantaneous trip setpoint, assuming the generator is capable of being paralleled? #246 There are very specific rules that govern the testing of generators found in the appropriate publication incorporated by reference. According to 46 CFR, Subchapter J (Electrical Engineering), which agency publishes the rules for the construction and testing of generators? #248 The turns ratio of the tapped step-down transformer shown in figure "C" of the illustration is four to one and all taps are equally spaced. If 440 volts were applied between 'H1' and 'H4', what would appear across 'X1' and 'X4'? Illustration EL-0082 #249 In figure "1" of the diagram shown in the illustration, the three phase step-down power transformer has a turns ratio of four to one. If a three-phase 440 volt supply is connected to terminals "A1-B1-C1", what voltage should develop across terminals "A2-B2-C2"? Illustration EL-0084 #250 In figure "2" of the diagram shown in the illustration, the three phase step-down power transformer has a turns ratio of four to one. If a three-phase 480 volt supply is connected to terminals "A1-B1-C1", what voltage should develop across terminals "A2-B2-C2"? Illustration EL-0084