The voltage drop is calculated in accordance with the following equation:
,where:
- In, rated current [A],
- l, length of cable [m],
- σ, conductivity, for copper 58 [S*m / mm 2 ],
- Un, rated voltage [V],
- s, cable cross-section [mm 2 ],
Voltage drop on cables between generators and main switchboard is not to be more than 1%
Voltage drop is not to exceed:
- 10% for lighting and signalling devices,
- 10% for power consumers at short-time and intermittent service,
- 7% for power and heating consumers,
- 5% for navigation light circuits,
Permissible voltage drop is given in:
- 6.8.5 and 16.8.3, Rules for the Classification and Construction of Sea-going Ships - Part VIII, Electrical Installations and Control Systems,
- 6.3.8 and 13.8.13, Rules for the Classification and Construction of Small Sea-going Vessels - Part VII, Electrical Installations and Automation,
- 6.5.7 and 14.6.3.2, Rules for the Classification and Construction of Inland Waterways Vessels - Part VII, Electrical Equipment and Automation,
- 15.2.3.1, Rules for the Classification and Construction of Floating Docks - Part VI, Electrical Equipment,
- 8.2.3, Rules for the Classification and Construction of Sea-going Yachts - Part V, Electrical Equipment,
- 8.2.3, Rules for the Classification and Construction of Motor Boats - Part V, Electrical Equipment.