Safety Standards of the Electrical Installations on Vessel
Electrical installations are a frequent source of fires. Therefore, the proper design, installation, maintenance, and use of onboard systems are essential for the vessel’s fire safety.
Cables installed on vessels must be technically compatible with the corresponding systems, but even more importantly, they must be suitable for the specific environmental conditions in which they operate. For the safety of the vessel, it is important to use only cables specifically designed for marine and shipboard applications.
The key difference lies in the conductor construction – marine cables use tinned copper wires, which significantly reduce the risk of corrosion at the connections and within the conductors themselves. Cables must also have appropriate insulation that does not support combustion and serves as fire-resistant insulation.
All power cables must only be connected inside junction boxes or cabinets with enhanced protection levels. Even in this case, connection points within the cabinets must be further protected with coatings against condensation and salt retention from the air. Elevated protection of distribution cabinets does not guarantee complete safety against the ingress of air, and thus moisture and salt. These substances deposit on surfaces after evaporation, creating hygroscopic layers that attract additional moisture.
Junction boxes must be made of materials that can prevent, or at least effectively slow down, the spread of flames originating inside them. Additionally, various technical solutions can be applied to reduce the negative impact of the marine environment, such as anti-corrosion sprays, boxes with controlled internal overpressure, and similar measures. Since these locations can be sources of sparking, regular inspections must verify the tightness of screw connections, not only mechanically but also by checking for conductor pull-out resistance.
When not used for power transmission, the shore power cable must be physically disconnected from the shore distribution panel to reduce the risk of voltage effects on damaged or degraded parts of the cable.
Cable routes should be installed according to class rules, providing adequate fire protection, with the aim of preventing the spread of fire. This applies especially to cables intended for the high-power transmissions, from one panel to another, or to larger consumers.
Such routes should be enclosed, and all cable penetrations through bulkheads must be executed using protective barriers, in accordance with the manufacturer’s instructions. Routes containing cables of different voltage levels must be separated by a safe distance.
Any additional interventions on the electrical installations must be carried out by authorized personnel, with the knowledge and approval of the classification society. The proper installation and operation of the electrical system must be checked during the vessel’s construction and throughout its service life.
Recipients: This safety lesson is intended for classification societies, flag state maritime administrations, yacht owners and managers, yacht crews, charter companies, and port authorities managing marinas and yacht harbours.
