Romanenko N. G. Increasing efficiency of ship cables defectation

The ship power supply system is a complex system that supplies electrical energy to various mechanisms and devices using wires and cables. The reliability of power supply largely depends on the technical condition of the cable lines. During operation, cable lines are regularly exposed to mechanical stress, both from external factors and from people. Some of the most common causes of cable damage are: aging insulation, overvoltage, thermal stress, boat vibration, and corrosion and moisture. Leaving the operating state of the cable line can lead to emergencies. A cable with damaged insulation can cause an electric arc with a metal object. If several phases of a cable with damaged insulation, then when they touch, a phase-to-phase short circuit occurs, as a result of which a large amount of heat is released, from which the cable insulation and other nearby combustible materials can ignite. There is considered the principle of operation of DIPCEL (a device for diagnosing ship cables) and shown its main disadvantages in determining the aging and moisture indicators of cable insulation. It is proposed to use the absorption coefficient for increasing the efficiency of measuring the ship’s cable insulation moisture. For insulating materials, in which the absorption current decreases rapidly, resistance measurements should be taken after 15 sec and 60 sec. The absorption coefficient is defined by measuring the ratio of a sixty-second insulation resistance to a fifteen-second resistance. If the value of the obtained coefficient is less than 1.25, then the insulation is unsatisfactory; if the value is within 1.25 - 1.6, than the insulation is normal, if more than 1.6 - the insulation is excellent