100mA RCD Incomming NOT TT but PME

[Bobster]

I have known on instances where a DNO will install a 100mA RCD (which then becomes the property of the consumer), where installations are very close to sub stations and have very high PFC and PSSC.

And why would adding an RCD to a circuit with a high PFC be of any benefit?

 

[Risteard]

And why would adding an RCD to a circuit with a high PFC be of any benefit?

I wondered the same...

 

[baldsparkies]

Probably a "short" answer would clarify why an rcd would not work as would be suggested here.:lol:

 

[davesparks]

I have known on instances where a DNO will install a 100mA RCD (which then becomes the property of the consumer), where installations are very close to sub stations and have very high PFC and PSSC.

Which DNO? I've read a lot of ukpns new service design paperwork and never yet come across this.
Also I can't see what the advantage could be for a high pscc? An RCD would not do anything except perhaps melt under excessively high short circuit current

 

[JD6400]

Haveing re-read Spins post and actually paid attention this time , I thought he had mentioned that it was because of a high Ze which was the reason why it had been done for the ones I have seen .

 

[Risteard]

I thought he had mentioned that it was because of a high Ze

That's definitely not what he said.

 

[Deleted member 26818]

Nope, nothing to do with high Ze, in fact one would expect very low Ze in such situations.
As to the why of it, I have no idea, I do not work for a DNO.
It sticks in my mind because the DNO installed the RCDs, then washed their hands of the devices, handing over ownership to the consumer.
Only mentioned it, as a possible explanation as to why the device is present.