In article ,
"PeteAlbright" wrote:

Many ships have ungrounded systems, with ground fault monitoring. Single
phase panels are used (without the neutral bus), or three phase panels (120
volt delta). All circuits use 2 pole breakers. Common ground monitor is
lights from phase to ground, if the light is out the phase is grounded.

Pete Albright,
Tampa, FL

"Larry W4CSC" wrote in message
...
On Sat, 27 Dec 2003 18:15:16 GMT, Larry wrote:


Being totally unfamiliar with naval systems, the question Rob asked
still
remains: Is the neutral (in a 60 - 0 - 60 system) connected to one of
the
60 volt legs? Is it still coded white? I'm assuming that ground is
always
connected to frame or earth ground in any system.

I'm sorry but I really don't remember. The last ship I was on with
this was USS Everglades (AD-24) completed in 1952. I was on her from
1966-1969 and I'm WAY too old to remember details back THAT far,
now....

But, as I remember doing some wiring in our calibration lab, I don't
think there was a "neutral" in that system. The 120VAC was from one
wire to another and I don't think the center tap of it was connected
to anything but ship's ground, as we didn't use the 60VAC for anything
to that center tap.






Pete is correct in that some on board wiring deletes the netral to earth
bonding altogether. In this situation you loose the fault current
protection generated when there is a fault from active to conductive
case of equipment. In this instance it is absolutely imperative to have
Residual Current Devices (RCD's) or GFI in NA parlance both on the shore
power inlet and the onboard generator. I just did an electrical survey
on a boat where this was the case. BTW downunder we have 240/408
single/3 phase 50 Hz systems.

John Proctor

--
John VK3JP