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It's how I was instructed to do it by the French "Conusule" who are the regulating body in France, the incoming main is into a S type RCD at the meter this is EDF equipment you have no choice.
That would also be a TT supply?
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It's how I was instructed to do it by the French "Conusule" who are the regulating body in France, the incoming main is into a S type RCD at the meter this is EDF equipment you have no choice.
I had this argument with someone a while ago, he wanted to protect a sub main to a summer house with a 40A MCB in the consumer unit and I was saying that if the 6A lighting circuit has a problem it could well trip the 40A MCB before the 6A one, it just depends which is the quickest to go.Mcbs are not likely to achieve selectivity. Using such devices for distribution is a poor design.
Selectivity will be poor, but sometimes it comes down to how important it is. For an occasional summer house it is probably acceptable risk, but not for many circuits in a home where loss of stair lighting, etc, has other hazards.I had this argument with someone a while ago, he wanted to protect a sub main to a summer house with a 40A MCB
Once you get pas the slow thermal trip side, many MCCB have a short-delay aspect (sometimes adjustable) of 20ms or so at modest overload currents, then once you hit really big faults in the kA range they go on an "instant" trip in the 10ms or less region to energy-limit the fault, just as MCB do.Are MCCB's less "sensitive" than an MCB then like fuses are, I'm no expert in commercial stuff.
Hence my suggestion of a small Ryefield!Fuses are old technology and cheap by comparison, but they naturally have a "delay" in how the wire heats up, and they offer exceptionally good energy-limiting. So if you really don't expect them to be blown/tripped, they are a very good alternative and will just sit there for decade after decade after decade, and still work if called upon.
If it is feeding sub-mains so 5s disconnect and all 63A or above it makes a lot of sense.Hence my suggestion of a small Ryefield!
Thing is, it's never just a heat pump, is it. It's some local sockets, a light or two...... so my choice would be to supply a small 4way 3ph board from said Ryefield. If you're building a plant room, build a plant room! Not some abomination of tails spaghetti.If it is feeding sub-mains so 5s disconnect and all 63A or above it makes a lot of sense.
But I think there is at least on 3P load for a heat-pump, that would be better served by some 3P MCB or similar so on fault all phases go down. Still a DIN box and MCB from a set of fuses is still quite a viable option.
Not some abomination of tails spaghetti.
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