Global IR testing on RCBO populated CU

[pc1966]

Ironically you mention fuses (neozed etc). Well, in five years time, only place you will see a fuse in this country is likely to be a museum

What about the incoming protection for the installation?

 

[LastManOnline]

What about the incoming protection for the installation?

A 63 amp mcb for a standard 12kva supply. As of February this year, new regs stipulate that now becomes a double pole 63amp

 

[pc1966]

A 63 amp mcb for a standard 12kva supply. As of February this year, new regs stipulate that now becomes a double pole 63amp

That is interesting. Certainly makes it easier to disconnect the CU supply to do any work!

It is just a regular MCB (not MCCB)?

Typically the use here of a BS88 fuse gives selectivity with many down-stream MCB characteristics as well as far higher braking capacity and fault current-limiting characteristics, but probably in most cases they are not essential (though some cities' supply points can deliver over 10kA PFC).

 

[Mike Johnson]

Wouldn't a S type RCD be better?

 

[nicebutdim]

Ironically you mention fuses (neozed etc). Well, in five years time, only place you will see a fuse in this country is likely to be a museum

Is this on the supply side or is Ireland moving away from fused plugs on domestic appliances?

 

[pc1966]

I think ROI is mostly TN-C-S now so no need for an incoming RCD. In any case there has to be some form of over-current protection so it would need to be an RCBO here.

 

[Mike Johnson]

I think ROI is mostly TN-C-S now so no need for an incoming RCD. In any case there has to be some form of over-current protection so it would need to be an RCBO here.

Of Course, but I do believe that the majority of rural ROI properties are still TT, but I have no facts to back that up except for the lodge I stay at in Enniskillen.

 

[nicebutdim]

Of Course, but I do believe that the majority of rural ROI properties are still TT, but I have no facts to back that up except for the lodge I stay at in Enniskillen.

Enniskillen is in NI.

 

[pc1966]

I think rural is often TT (or to all intents and purposes, TT) in most of the world, as you don't easily get a low R earth and you might want to avoid the transformer's LV one as it may be too close to any HV side earth.

 

[LastManOnline]

That is interesting. Certainly makes it easier to disconnect the CU supply to do any work!

It is just a regular MCB (not MCCB)?

Yes.The difference between it and the other mcb, s is that it may be a "C" instead of a"B" type if the supply characterises allow. You raise an interesting question in my mind though as to why it can be a regular MCB instead of an MCCB and offhand I suspect it may have to do with the DSO, s protective fuse in the meter cabinet. Must look into that.
Regarding the DP main switch, well that is simply a gift for a number of reasons but chiefly we can now do IR tests effortlessly on non - rcd protected circuits on TNC-S systems without having to first disconnect the main Neutralising earth from the bus-bar.