Question 426Electricity & Electronics - Assistant Engineer

The correct answer is C) 21.1 VDC. According to 46 CFR Subchapter J, Section 111.15-10, emergency storage batteries for vessels of 1600 gross tons or more must be able to power the emergency loads for a minimum of 18 hours. Assuming a nominal voltage rating of 24 VDC, the minimum allowable voltage after the 18-hour discharge period is 21.1 VDC. This is because the batteries are expected to discharge to no less than 88% of their nominal voltage rating, which is 24 VDC x 0.88 = 21.1 VDC. The other options are incorrect because 16.0 VDC is too low, 18.8 VDC is below the 88% threshold, and 22.8 VDC is above the minimum allowable voltage.