when is a ring main not a ring main

[JohnW2]

You only have to look at the physical design to see it's a rcbo ?

You're obviously wiser and more clever than me. To me it looks like an RCD (RCCB if you want), and the fact that it is labelled "RCCB" merely reinforces that impression. AAMOI, what aspects of the physical design make you so sure that it's an RCBO?

...and 30 is a clue...

As I said, it is indeed a clue. However, would you really 'assume' than an unfamilar device (labelled 'RCCB') provided over-current protection just because of that clue?? I personally certainly wouldn't dare make such an assumption.

Kind Regards, John

 

[deadshort]

Why ? 30A is a current rating !

DS

 

[JohnW2]

That's all true - but 'normal' RCCBs have a current rating so even if it had said 30A in clear markings that would not have actually helped.

Exactly - and, as far as I'm concerned, the "RCCB" marking trumps everything - at least to the extent of raising doubts as to whether the device provides over-current protection. As I've just written to DS, I wouldn't dare 'assume' that it did provide such protection (from a device labelled 'RCCB'), even if it had 30A written on it!

Kind Regards, John

 

[JohnW2]

Why ? 30A is a current rating !

I presume that EFLI's point is that, even if it had 30A written on it (without any clear indication of what that meant), that could be the maximum current rating of an RCD/RCCB which did not provide any over-current protection.

Most of the RCDs we see in CUs have "63A" or "80A" written on them - and you obviously don't think that means that they provide over-current protection at those currents - so why would you think differently if it said "30A" (and "RCCB")?

Kind Regards, John