If the trip threshold were still 5 milliamps then it would be awful easy to trip out all the power for the building and leave the occupants scrambling for a light source to see their way out to the main source to reset it. Seems like a bad idea to me.
First I have to ask why would it be bad to have GFCIs in more locations?
I doubt that we will see a 200 amp GFCI main with 5 ma trip.
I believe many European homes are required to have a type of GFCI main but the trip level is higher than 5 ma.
Services and feeders larger than 1,000 amps and 150 volts to ground are required by the NEC to have ground fault protection however the trip level is often a few hundred amps or more. These GFP systems do not protect personal like GFCIs do.
Bob Badger Construction & Maintenance Electrician Massachusetts
Exactemunto! So why have my poco, EDF, fitted a 500ma one at my entry? The bloody stupid useless thing pops off at the slightest sniff of a thunderstorm within 100 miles, and it's a manual reset. We have to go round the house resetting the fax, the timers, vieo, clocks etc.. We can't rely on the heating for frost protection in winter if we go to the UK, so have to drain down the domestic, and the heating system is 50% antifreeze filled for protection. All the distribution network here is overhead, ( except for the latest stuff going underground, prompted by a tempest in 2000 which blew so many poles over they had to import English linesmen to get the work done. Some poor sods were off power for two months!) When I asked the Poco if there was an auto-reset type, all I got was a gallic shrug, eyes rolled up and that peculiar " Les Anglais!" look. Does an auto-reset type even exist?
Real life experience ... I have all of the exterior lighting around my screen cage on a single GFCI circuit. It trips a lot and I never find a single box or fitting that is leaking enough to show up on a meter but the combined leakage from all of them trips the GFCI. I still like the idea of GFCI enough to keep it but I may split up the circuit
I can't imagine the combined leakage of a whole service being under 5ma or even 30ma.
As Alan said, that is a MAJOR problem this side of the great pond, our GFCIs are rated 30mA or 100mA, but Alan's 500mA trips on thunderstorms, as do ours. It's so bad that the current wiring regulations here (our version of the NEC) highly recommend *NOT* using one for the main.
A time delayed type might be less prone to nuisance tripping, but individual circuit protection is IMHO far less inconvenient, it also gives you a fighting chance of finding out where a ground fault is without having to dismember the panel.