[Milsurplus] AC Power on Ships

[w8au at sssnet.com]

At 06:18 PM 10/24/2010, J. Forster wrote:
>I was just asked about the AC line on WW II era ships. It appears there is
>no neutral and the 115V 60 Hz just floats with each line 60-80 V AC above
>structure.
>
>Is this correct and common or is there a fault?

This is correct for all mains service (120V single phase, 240/3phase 
and 440/3phase.)

Avoiding neutral grounding to hull also helps to minimize 
electrolysis and current flows from
hull to pier or ground.

Some Historic museum ships (no longer government operated) get into 
trouble with this
when regular (civilian) electricians do volunteer work aboard.

In testing with immersible "wet cell" (in water) against hull ground 
(for electrolysis) I could
not get reliable voltage readings until inadvertent neutral grounds 
were lifted.  Each change in
shore power load caused fluctuations.

Perry