An interesting read

[EFLImpudence]

it must be flowing between the incoming neutral and your main bonding (i.e. to incoming water pipe etc.)

Or vice versa.

 

[andrew1210]

sorry, to be clear, it's there when the dno fuse is in, and seems to be effected by load. It is also there, but nowhere near as bad, with the dno fuse out (ie, It's like an 'idling' current) IQA did check the bonding and equipotential thingiry jigeries whilst out on both ocassions but came back saying there was nothing wrong.

*A similar situation is also apparent in both neighbours, and across the road, but no tripping, as they were rewired by the L.A. last year like we have been today*

Now I have an interest and a fair understanding of electricity, but Earthing is an area I'm not too keen on!

The PIR report is being sent out next week, I'll scan in and post up so you can see all the values if you'ze want and try to see if you can understand it any more!

edit: missed some info.

 

[JohnW2]

it must be flowing between the incoming neutral and your main bonding (i.e. to incoming water pipe etc.)

Or vice versa.

Sure, that's what I meant, and thought I had expresed clearly. I decided against using 'to/from' in favour of 'between', since I though that made it clearer that I wasn't not meaning to imply anything about direction, but I seem to have failed

Kind Regards, John.

 

[JohnW2]

sorry, to be clear, it's there when the dno fuse is in, and seems to be effected by load. It is also there, but nowhere near as bad, with the dno fuse out (ie, It's like an 'idling' current).

OK, but if it gets worse when the fuse in in and the load is increased, that implies than an appreciable part of the return path for your loads is via the earthhing conductor rather than the N conductor (until they join at the cutout) - which could only really be due to something very wrong within your installation - which I thought we had established is not the case.

This really will make a good film (after you've first written the book)!!

Kind Regards, John.

 

[andrew1210]

OK, I'm confused too, I can see your point but this also happens in other property's so I don't know how this happens! but yes, it was FULLY investigated with the PIR, then an extended look at the entire house tracing each cable from start to end. Floor boards up, loft checked all over and nothing could be found by either of the two (and I must say very experienced) electricians sent out.

RE: the film/book - I suppose this forum is entitled to a cut of the profits? lol

 

[JohnW2]

OK, I'm confused too, I can see your point but this also happens in other property's so I don't know how this happens! but yes, it was FULLY investigated with the PIR, then an extended look at the entire house tracing each cable from start to end. Floor boards up, loft checked all over and nothing could be found by either of the two (and I must say very experienced) electricians sent out.

Very odd. Logic seems to suggest that if an increased load on your installation results in a substantial increase in current (rather than tiny increases die to leakage currents) in the earthing conductor, then the return path from those loads must be at least partially via the 'earthing' (CPC) wiring - which makes no sense, given your 'clean' PIR.

RE: the film/book - I suppose this forum is entitled to a cut of the profits? lol

No, not 'the forum' - only those forum members who have participated in this thread

Keep the updates coming!

Kind Regards, John.

 

[andrew1210]

I certainly will be, you may have noticed I like getting things off my mind and down on, well.... this forum!

and yes, I think it's fair that yourself and a few others get a cut of the profits. Meanwhile, the old CU is probably away to the national history museum, look out for it, and steer well clear!

Thanks again

 

[westie101]

I think the clue came from an earlier comment by Andrew that one of the SP guys mentioned a broken (possibly high resistance) neutral. If this is between him and the transformer some of the current from customer loads could use the numerous parallel paths via customer bonding as a return path for the load current (and any fault current if there is a fault on a customer's wiring somewhere)

I had something similar a few years ago, a very careful check of the loads on all three phases and a lot of work balancing it along with remaking connections on the neutral/earth of the overhead line reduced it to manageable proportions. As with Andrew's we are planning to replace the whole lot in time

 

[JohnW2]

I think the clue came from an earlier comment by Andrew that one of the SP guys mentioned a broken (possibly high resistance) neutral. If this is between him and the transformer some of the current from customer loads could use the numerous parallel paths via customer bonding as a return path for the load current (and any fault current if there is a fault on a customer's wiring somewhere)

Indeed, but surely they should know, not be speculating, whether there is such a broken/high resistance neutral - and if they know it's there, should have identified by now where (or, at the very least, roughly where) that fault exists?

Kind Regards, John.

 

[westie101]

Yes they should, it isn't that difficult

 

[andrew1210]

See they were at all the poles working live disconnecting blocks at a time to see if the fault dissapeared so technically all high level connections were redone. I'm convinced it's at the tranny, due to it's awful history (It has a criminal record longer than the line the SP engineers running away from our house!)

 

[andrew1210]

Hello, I know it's been a while, but to round things off........

We have had no further issues with RCD trips, however the neighbour is still occasionally effected. last week I noticed Scottish Power were back in the street and it turns out they were at another block of neighbours down the road complaining of the same problems we were facing.

I invited them into our house to check the Earth reading and it wasn't quite as bad as it had been, however still 1/2Amps, and fluctuating. I don't know what they plan to do, but they say they "haven't forgotten"

At least our house isn't tripping any more!

 

[securespark]

Surely the knacked RCD would have been picked up on the PIR?

I smell a DNO sized rat here....

 

[andrew1210]

your not the only one thinking that!

don't forgot the second "extended" (whatever the hell that means) PIR but I'm glad Scottish Power see i'm not the only one! Some backup is nice once in a while!