Got the responsibility for a 100 yrs old building, The elctric systerms was rewired at lo cost 15 yrs ago. When I com in the morning at least one, sometimes 15 FFCI had don their job... but all measuring shows nothing wrong.
We have a 230V 3 phase supply quite equal to US 208V delta systems. (I'm in Norway) All this is wired for 230V single phase.
All hints to find and make documented reports are welcome.
