is that above 32A there is some tolerance / leeway in the requirement for 30mA RCD sensing?

If you're going down the isolating transformer route, this is probably superfluous, but just for completion...

In general 30mA is for additional protection The rating of the circuit doesn't really come into that. As Graham mentioned, it the fact that it supplies sockets (rated ≤32A) that triggers the requirement, or any domestic lighting circuit, or soft sheathed cables concealed in walls, or any bathroom circuits.  On TT systems (and occasionally elsewhere too) you'll need RCDs for ADS - but that doesn't necessarily mean an 30mA device - 100mA, 300mA or 500mA devices could equally be used if the circumstances are right (Ra etc) - time delayed too if you like.  So if the machine is hard-wired, and the cabling is either surface mounted or is armoured (or similar) the 30mA requirement could well not apply.

If you are using an isolation transformer, keep and eye on switch-on (magnetising) surges - something large enough to supply 7.5kW might well nuisance trip the usual domestic B-type 32A MCB/RCBO.

200mA is a very odd recommendation - it's not one of the preferred values for an RCD and I've never come across such a beast. If that's got lost in translation, I wonder what else has? (I've no idea of what they mean by "candling" the leakage protection switch).

   - Andy.

Yep, agreed. The 200 mA is probably a 'global' figure of what they believe is required, not set on anyone's standards as such. Candling is Chinglish ... no idea either.

(I've no idea of what they mean by "candling" the leakage protection switch).

I think we can assume it is not a flame test - based on experiance with other Chinglish texts for IC datasheets and so on, I would translate as "delay type" ( perhaps this is metaphoric by analogy with slow burning candles as clocks? Dunno ) .

Actually, before we laugh too much, calling our slow RCDs 'selective' but our slow fuses 'Trage' and instant fuses  'Fink' makes not a lot of sense either unless you know the long history.

200mA is a possible but never used setting on some earth fault relays of the kind you take out a mortgage for (RH197M for example is about £400 quid !!  ). Here 300mA is more common and will discriminate bettter with things below. I like to see factors of 3 between protection tiers-  1/3 second 300mA., 0.1 second 100mA, 30mA instant is an easy and memorable hierarchy, and usually, rock solid and reliable.  

Mike

yup 200mA setting. No normal use case needs it..

(I've no idea of what they mean by "candling" the leakage protection switch).

I think we can assume it is not a flame test - based on experiance with other Chinglish texts for IC datasheets and so on, I would translate as "delay type" ( perhaps this is metaphoric by analogy with slow burning candles as clocks? Dunno ) .

Actually, before we laugh too much, calling our slow RCDs 'selective' but our slow fuses 'Trage' and instant fuses  'Fink' makes not a lot of sense either unless you know the long history.

200mA is a possible but never used setting on some earth fault relays of the kind you take out a mortgage for (RH197M for example is about £400 quid !!  ). Here 300mA is more common and will discriminate bettter with things below. I like to see factors of 3 between protection tiers-  1/3 second 300mA., 0.1 second 100mA, 30mA instant is an easy and memorable hierarchy, and usually, rock solid and reliable.  

Mike

yup 200mA setting. No normal use case needs it..