Low-Voltage Shore Connection Power Systems: Optional Designs and a Safety Loop Circuit

This article reviews low-voltage shore connection (LVSC) power systems for ships with up to 1,500 kVA and voltage of 400-690 V. The design concept for these systems is contained in the current LVSC draft standard, International Electrotechnical Commission (IEC)/IEEE 80005-3. Here, we attempt to clarify that an LVSC design concept using multiple parallel feeder circuit breakers does not violate National Electric Code (NEC) National Fire Protection Association (NFPA) 70 Section 240.8. We also attempt to clarify the optional design for an ungrounded shore power system, as required by certain ships and included in the draft standard [1]. In addition, we review the safety loop circuit that enhances operator safety both onshore and onboard a ship.