In a cruise ship that is 1000 ft long and 300 ft wide, a 3-phase, 4160 V main feeder from the generator switchboard distributes 1200 kVA hotel load to 12 sectors fed by 1-phase, 100 kVA, 120 V lateral feeders as shown in Figure P8.9. Each junction of the main feeder and the lateral feeder has a 1-phase, 100 kVA, step-down transformer for 120 V cabin loads.

Determine:

(i) the size of the main and lateral feeders,

(ii) voltage available to the last lateral feeder at point E, and

(iii) voltage available to the last cabin at point EE.

Assume:

(i) 0.85 pf lagging load, and

(ii) both feeders have uniform size from the start to the end of the line (versus it can have tapered cross section as the load current decreases from maximum at the start to the minimum at the end).

Other loads (12) 100-kVA, 1-ph lateral feeders on port and starboard sides E 300 ft Propulsion loads 1000 ft- EE FIGURE P8.9