IEC 60092-503-2021 Electrical installations in ships – Part 503: Special features – AC supply systems with voltages in the range of above 1 kV up to and including 36 kV

IEC 60092-503-2021 Electrical installations in ships – Part 503: Special features – AC supply systems with voltages in the range of above 1 kV up to and including 36 kV. 4 General requirements 4.1 Environmental conditions Environmental conditions shall be in accordance with relevant requirements of IEC 60092-1 01 . 4.2 System design System design shall be in accordance with relevant requirements of IEC 60092-201 . 4.3 Personnel safety Particular attention shall be given to the safety of personnel during the installation, operation and maintenance of equipment. This shall include – manuals and instructions for transport, storage, installation, operation and maintenance, – special tools required for operation, maintenance and testing, – safe working procedures developed for specific locations, and – safe earthing measures. High voltage equipment shall be designed to limit the risk of arcing faults and contain possible arcing faults in such a way that the risk for operators is reduced to a level acceptable to the appropriate authority during internal fault conditions. 4.4 Operational safety Control and protection systems shall take into account that continuous power supply is essential to ship’s safety. The design shall be such that unnecessary tripping or de-energisation is avoided. 4.5 Integrity of external power supply If the power supply is divided into more than one switchboard, in order to provide power supply availability in case of a single point failure (typically under fire condition), it shall be designed and protected such that any single point failure does not jeopardize overall functionality of the other switchboards. 4.6 Electrical and mechanical interlockings Interlocks between different components of the equipment are provided for reasons of safety and for convenience of operations. The following provisions are mandatory for main circuits. Apparatus installed in main circuits, the incorrect operation of which can cause damage, or which are used for assuring isolating distances during maintenance work, shall be provided with locking facilities (for example provision for padlocks). Access to operation of a circuit-breaker, switch or contactor in the switchboard shall be limited by a “safety system” which co-ordinates other apparatus involved such as motors, transformers, generators, switchboards, etc. Back-feeding through transformers and shut off of starting air and oil to engines shall be taken into consideration. Earthing switches having a short-circuit making capacity less than the rated peak withstand current of the circuit shall be interlocked with the associated disconnectors. NOTE According to 7.2.1 , the requirements of IEC...