210.8 is supposed to be all about personnel protection, which is what class A GFCI is about. That said, I think class A probably should mostly only apply to swimming pools and maybe bathrooms or similar areas and class B to most everything else.210.8 should be amended to only require (RCD) UL Class B GFCI protection (30ma) for 120/240V single phase 30-50A receptacles. As most are actually 'feeders' in a sense. A 5ma ground-fault on a 120V RV, food truck or spider box receptacle will take out the 'feeder' GFCI before the GFCI receptacle the problem load is plugged into, causing potentially a much larger hazard.
I put a old hot tub 50A GFCI on my RV receptacle years ago and noticed that when a GFCI tries to trip the main goes instead.
Yes 120, 208 and 240 are nominal system voltages, 125 and 250 are common nominal device ratings.Just a question in passing from that Brit again.
I didn't think you used 250Vac over there?
Or is that just the nominal voltage rating of the receptacle?
Then when you get into 277 and 480 the system volts and devices are all typically rated 227 and 480 - makes sense right?