See how this boiler stipulates type A RCDs
must be employed where additional protection is required. I think 'addition protection' means where it is a TT supply, but not sure, it could be simply because a mid position valve may be used,
Clearly a diode is used to stall the motor, however the problem is not so much that it need a type A, F, or B but we really don't know the risk when using a type AC. We have had DC equipment for years, old cathode ray tube TV's with volt droppers (big resistors) often using half wave rectifiers, and it was also a good method to get half power.
We have never had RCD protection without some DC, so big question we all ask is what has changed?
Supplies to caravans and boats for years had to be TT, and the fire regulations ensured think from memory 2.6 meters from buildings, and an electric car is no different to a caravan, so want a TT supply, however can't use a TT supply as often too close to the house, so another method had to be found, when the method of dealing with an electric car fire is to put whole car in a container of water, not sure I want one closer than 2.6 meters anyway, it seems there is an effort to
play down the problem but videos like this
are not helping, and I know petrol and diesel cars can also catch fire, but rare when simply parked up.