Shorting neutral to Earth confusion

[Rippetherocker]

Benefits: Ungrounded delta can take one leg shorted to hull and still work at full power, with a two leg short down the line the switchboard can disconnect one shorted leg at the generator an still have two phases on-line. Disadvantages? Not many on a warship where having some power could be the difference between life and death. Most of our critical equipment had a 'battle-short' switch because 'it's better to risk having a technician or two killed trying to fix something than to have the whole ship destroyed"

Battleshort

Thank you for the info. As i understand it wouldn't a Y 3 phase isolated neutral work the same way? One phase short to hull is no problem. If 2 phases short then usually the genset trips though it can reconfigured to isolate one phase.
Or am I just being dense? Lol

 

[dlgoff]

BTW, there's no ground wire at the remote barn -- it's all old 2 conductor wiring & 2 prong outlets.

Not just old barns but old homes where neutral was ground; as in water pipe. My first encounter with electricity was at about age 5 when getting a drink from the outdoor hose faucet barefooted on a hot summer day.
Funny how pipes can have a high resistance to ground. Maybe that was what "sparked" my interest in electrical things.

 

[Jeff Rosenbury]

Thank you for the info. As i understand it wouldn't a Y 3 phase isolated neutral work the same way? One phase short to hull is no problem. If 2 phases short then usually the genset trips though it can reconfigured to isolate one phase.
Or am I just being dense? Lol

In an ungrounded delta, each phase floats. So if you ground one leg, all three still work normally. Ground is just referenced to one of the legs when it becomes grounded. The circuits still act normally. At least theoretically. (I'm not sure how wise that would be though.)

In a Y, grounding one leg will place the neutral at a high voltage. Then the currents through the neutral are different (higher?). In addition someone touching the neutral thinking it's safe will be in for a shock.

 

[Rippetherocker]

In an ungrounded delta, each phase floats. So if you ground one leg, all three still work normally. Ground is just referenced to one of the legs when it becomes grounded. The circuits still act normally. At least theoretically. (I'm not sure how wise that would be though.)

In a Y, grounding one leg will place the neutral at a high voltage. Then the currents through the neutral are different (higher?). In addition someone touching the neutral thinking it's safe will be in for a shock.

There is no neutral on ships. And very cool smiley!