I have been looking for the history of switching the neutral at each breaker. Although in most cases, it is not required per IEEE 45, USCG Title 45, and ABS just to name a few, I come across this in older steel vessels. I think it is a relic from the ol' ungrounded days. This would explain I see this in older ships that have been since retrofitted with grounded systems but kept the origional distribution system due to the expense. Can anyone shed actual knowledge on the history?
