Three wires or four wires (Neutral Grounded)???!
At the moment we are doing on design and production of two 50 meter explorer yacht.
Yachts are under:
a.Classification Society:American Bureau of Shipping
b.Class notation:ABS +A1 (E), Commercial Yacht, Ice Class D0, +AMS
c.Statutory Cod:MCA LY2 > 500GT
Hull (steel) and superstructure (Al) are ready for outfitting. To get back to subject.
Past days we had a lot discussions with our contractor for electrical system. Main issue is type of electrical system. Three wire system or four wire system (with grounded neutral)? Talking about voltage of three phase 380V50Hz and single phase 220V50Hz. A lot of devices on board are 220V and made for domestic usage so neutral is required.
If we decide to proceed with three wire system (without neutral) there is a requirement for huge transformers that can provide 220V and neutral. Other wise if we go with four wire system we can get 220V between one phase and neutral so we do not need additional transformers.
Please to advice me about "common practice" for yacht industry in range 40-60 meter vessels regarding type of electrical system, "three or four wires"
In addition to all above here is a cut from RINA rules