External garage electricity wrongly connected to neighbours supply

[ericmark]

Working with this

as the volts increase, so does the mA leakage, at 4 volts within limits, at 12 volts near the edge, and by 15 volts tripped.

 

[JohnW2]

Working with this ...... as the volts increase, so does the mA leakage, at 4 volts within limits, at 12 volts near the edge, and by 15 volts tripped.

Yes, but only because you have introduced a 500Ω N-E fault.

As I've written, if there were any loads on the installation, introducing such a fault path would cause the RCD to trip even if the N-E voltage were zero.

 

[SUNRAY]

is it 1A? Do I get a lollie?
Until the rcd trips

Give me your address, I'll put a cornetto in the post.

 

[SUNRAY]

So 1 amp for around 20 milliseconds, but would not be able to set the RCD on.

Well you can when the ammeter is taken away.

 

[SUNRAY]

Many electricians in my experience, do not understand that a N to E short can trip an RCD.

Far too many in my opinion.

 

[SUNRAY]

Yes, but only because you have introduced a 500Ω N-E fault.

As I've written, if there were any loads on the installation, introducing such a fault path would cause the RCD to trip even if the N-E voltage were zero.

Well in the above mentioned garage there were NO LOADS running, are you trying to say the RCD shouldn't trip?

 

[SUNRAY]

lol

That would have been more amusing to find out they that been in the wrong garage for some time, esp. if they had been modifying it with shelving, workshop things etc.

That is what happened further along the row

...Apparently further along the row there had been a mix-up with which garage was being used when a house sold and buyer found his garage keys didn't fit ...

 

[SUNRAY]

Other than in TN-C-S installations, there is not uncommonly a significant N-E potential difference (due to VD in the supply neutral) - and, indeed, even with TN-C-S there is not uncommonly a significant PD between the CNE/PEN (hence N & E within the installation) and 'true earth' (for the same reason). However, in no case does that result in any 'potential for tripping' of an RCD.

Some 50 years ago we usually had enough voltage N-E to be able to rectify it and float a car battery on it to run my 19set on it's dynamotor. I ran it like that for a couple of years without any other form of 'charging'.

 

[JohnW2]

Well in the above mentioned garage there were NO LOADS running

Maybe, but (a) you hadn't told us that, having merely written ...

.... N-E has over 1V so some potential for tripping, .....

... and (b) I have consistently made it clear that I was talking about the situation in which there were some active loads in the installation., and ....

in the above mentioned garage there were NO LOADS running, are you trying to say the RCD shouldn't trip?

Not at all. On the contrary, I'm not only saying that the RCD should trip in the situation you described, but that it should also trip (in almost all real-world situations) even if the N-E potential difference were zero. I say that because, even if the N-E pd were zero, the RCD would be expected to trip if there were any significant loads anywhere in the installation (not necessarily in the same final circuit, nor even a final circuit protected by the same RCD) - and (other than for an unoccupied property) it would be an extremely unusual real-world situation for there to be no significant loads on any of the circuits for any appreciable period of time.