Voltage drop, 3-phase AC

cable cross-section:
[mm 2 ]
length of the cable from a source to the consumer:
[m]
maximum current:
[A] or power [W]
rated voltage:
380 V, 400 V, 440 V, 600 V,
cos( φ):
calculated voltage drop:
_ [%]

The voltage drop is calculated in accordance with the following equation:

,gdzie:

  • 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.
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