Ungrounded-LV distribution has been correctly discouraged for ~50 years. A prime example is a classic excerpt in
Beeman . The mode of thinking that has allowed it to remain (and proliferate
!) is, “Done it that way since 1943 when the family first came from the
old country.”N.B.: OTOH,
high-resistance system grounding is encouraged and well documented. Such configurations inherently employ ground detection, and, properly applied, inhibit the kind of overvoltage damage described in the Beeman text.
[This message has been edited by Bjarney (edited 04-23-2004).]