Question

I have seen Electrical Equipment designs that have many voltage levels requirements as:

• Lighting and trace heating  230V 50Hz, alternatively 240V 60Hz
• General services   400/230V 50Hz, alternatively 480/277V 60Hz
• Emergency services   400/230V 50Hz, alternatively 480/277V 60Hz
• Large Electrical Heaters & VSDs 690/400V 50Hz, alternatively 600/346V 60Hz
• Instruments and Emergency Systems   230V 50Hz, alternatively 240V 60Hz, 24V DC
• Communications   230V 50Hz, alternatively 240V 60Hz, 24V DC

So instead of many requirements, can someone share experience on typical design system that accommodate all of the above designs?

Answer 1

The EPC Companies typically will standardize the Low Voltage (LV) distribution system for the entire FPSO to match the existing LV distribution system of candidate tanker.  

This will include 440V 3-phase 60Hz and 220V, 1-phase 60Hz for topside.

This will eliminate the need for two additional back feed transformers (cost impact) and will also allow for a standardized design basis which will have a positive effect on operability and maintainability.