I am facing a significant voltage drop (for every 3 kW of load there is a drop of approximately 1 V) when the ship's shore supply is connected to the yard shore supply's distribution panel.

The yard shore supply distribution panel is being fed a from a substation. The substation consists of a 1250 kVA, 6600 to 415 V transformer. A further 800 A ACB is taking input through this transformer and a 200 kVAr APFC panel is connected (currently non-ops) and furthermore this 800 A ACB output is feeding a 630 A MCCB.

A 2 x 3.5C x 185 mm2 aluminium cable is connected at the output of the 630 A MCCB which feeds the yard shore supply panel at a distance of 1000 m. 1 Here is Diagram link]

How to solve this problem? I am not able to connect a load to the panel. How can this be corrected?

  • 2
    \$\begingroup\$ Draw a picture instead of describing. Add voltages under no-load and voltages under full-load. \$\endgroup\$
    – Andy aka
    Oct 8, 2022 at 9:25
  • \$\begingroup\$ Use a bigger cable or split the load between two cables - simple load management. \$\endgroup\$
    – Solar Mike
    Oct 8, 2022 at 10:44
  • \$\begingroup\$ Yeah yeah i know so much information. Voltage at Shore supply panel is 415V and on no load voltage in ship Main switch board is 413V . Ship carries mostly inductive load viz big motors, ac compressors, galley, lighting load etc. \$\endgroup\$
    – Anil Meena
    Oct 13, 2022 at 16:44
  • \$\begingroup\$ To replace cable at this moment is not really feasible for me. AVR or capacitor bank on the load side would it be of any help? Pf of ship's load is maintained at around 0.78 \$\endgroup\$
    – Anil Meena
    Oct 13, 2022 at 16:51

1 Answer 1


The 1 kilometre cable from MCCB to yard shore supply is where the voltage drop is occurring.

See screenshot from this voltage drop calculator below:

enter image description here


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