[Milsurplus] AC Power on Ships

[Bill Breeden]

One very good reason for using a grounded system for AC power distribution 
to the general public is the possibility of a short between the primary and 
secondary windings in a distribution transformer.  Imagine what would happen 
if the power company's distribution system was floating and this occurred in 
the transformer feeding your home along with a ground on the primary side 
feeding the transformer.  Running a "hipot" test on your home with what ever 
voltage is on the other side of the transformer is not likely to produce 
favorable results.

73,

Bill - NA5DX

> ------------------------------
>
> Message: 7
> Date: Mon, 25 Oct 2010 09:39:48 -0400
> From: Richard Brunner <brunneraa1p at comcast.net>
> Subject: Re: [Milsurplus] AC Power on Ships
> To: jfor at quik.com
> Cc: milsurplus at mailman.qth.net
> Message-ID: <1288013988.1978.14.camel at richard-desktop>
> Content-Type: text/plain; charset="UTF-8"
>
> One last word on grounded vs ungrounded AC power systems.  For years the
> NEC has been pushing grounded systems for, I believe, entirely specious
> reasons.  Today you will only see ungrounded systems used where
> continuity of service is very important, such as refineries, chemical
> factories, cement works, etc.  On a ship grounded is ok until you
> connect to shore power, then stray currents go through sea water to the
> hull and the hull starts to dissolve.
>
> Richard, AA1P