Question 422Electricity/Electronics - Assistant Engineer70% to pass
You are in the planning stages of replacing a battery charger, where an exact duplicate of the charger to be replaced is not available. Obviously the charger must be suitable for the battery to be charged. According to 46 CFR, Subchapter J (Electrical Engineering), which of the following is a true statement concerning battery chargers?
AI Explanation
The correct answer is B.
According to 46 CFR Subchapter J, battery chargers incorporating grounded autotransformers must NOT be used, and if the charging voltage exceeds 20% of the battery line voltage, automatic protection against reversal current must be provided. This is because grounded autotransformers can create a potential safety hazard, and the 20% voltage threshold is to ensure the battery is not overcharged, which could damage the battery.
The other options are incorrect because they either allow the use of grounded autotransformers (C and D) or have the voltage threshold reversed (A).
Related Questions
#420 The torque produced by a DC motor armature is the multiplication product of two factors, one being the density of the magnetic flux which is dependent upon the field current. What is the other multiplication factor? #421 What is the name of the DC motor speed control method utilized as shown in figure "B" of the illustration? Illustration EL-0101 #423 Suppose a cargo vessel of 1600 gross tons or more is fitted with emergency storage batteries for the purpose of supplying emergency lighting and power. According to 46 CFR, Subchapter J (Electrical Engineering), the capacity of the storage batteries is such that they should be able to successfully power the emergency loads for a period of 18 hours. Beginning with fully charged batteries, what is the minimum allowable percentage of the voltage rating of the batteries after the 18 hour discharge period assuming a nominal voltage rating of 24 VDC and operating at rated capacity? #424 According to 46 CFR, Subchapter J (Electrical Engineering), which of the following statements concerning battery installations is correct? #425 In accordance with 46 CFR Part 112, a storage battery for an emergency lighting and power system must have the capacity to accomplish which of the following?