Voyage to safety

The power requirements on modern marine vessels are increasing. Many of the loads are changing from mechanical to electrical, and the propulsion systems are becoming all electric. Traditional low-voltage (LV) 480-V systems do not have the ratings to handle these large power requirements. Power will have to be generated at higher voltages, typically 4,160 V, 6,600 V, or above. These voltages must have medium-voltage (MV)-rated switchgear. Presently, commercial marine standards call for off-the-shelf-type switchgear. MV switchgear is not common in today´s marine industry. The isolation of being in open waters demands that the personnel on board perform some maintenance and repair to the switchgear to keep the vessel operating. The inexperience of the personnel on such equipment can be life threatening if the proper safety devices are not provided. Focus must be placed on the operation, repair, and maintenance of MV marine switchboards and the variables that differentiate it from land-based applications. This article reviews effective apparatuses that would enhance safe operation and maintenance if installed in commercial off-the-shelf MV switchgear. Some of the apparatuses to be considered are remote controls, arc-resistant switchgear, glow tubes, earthing switches, ground-and-test (G&T) devices, and remote electric racking.