The old Heineman and Fuchs breakers had a 60Amp earth leakage as a mains, with overload protection. We still have a couple of them here by us. Also the lights were normally not on earth leakage since the old 5 foot ballast lights caused nuisance tripping.
Many reasons why the earth leakage can trip.
Best advice, get a good qualified electrician. I know they come at a price but is worth every cent, alot cheaper then a burned down house!