very high r1 result!

[HappyHippyDad]

Afternoon all..

I have just been testing a ring final circuit and got r1 = 107Ω

It is TNCS, rN is 0.4Ω

I'm sorry I haven't got anymore results for you, I'm nowhere near home at the moment and those are the only 2 results I can remember.

This is on a kitchen ring and the Kitchen is being ripped out over the next week and I shall be reinstalling a ring in the new kitchen. This will be a good time to find any fault but...

My question is what could give this kind or result? 107 is huge! I initially thought loose connection, but even if the conductor was just brushing the socket terminal I would have thought it would be far lower than that?

Thanks..

 

[HandySparks]

so how would the load resistance get from the load neutral back to the other L leg of the rfc? (always assuming that the N legs are dissed from the DB as they should be when measuring r1,rN, r2).

As I said, two or more appliances. At least one each side of the break, obviously.

 

[marc8]

Why not just split it down until you find the high resistance joint or damaged cable

 

[Englishman]

Come across a few like that and the problem has been at the mcb, where one of the two cables has been put the wrong side of the little termination clamp.

 

[campo]

Could it be a screw is on the insulation not the wire?

 

[telectrix]

Come across a few like that and the problem has been at the mcb, where one of the two cables has been put the wrong side of the little termination clamp.

cable ends would be out of the mcb for testing r1. nice try though.

 

[telectrix]

Could it be a screw is on the insulation not the wire?

quite possible.

 

[telectrix]

As I said, two or more appliances. At least one each side of the break, obviously.

that's about the only way it could happen.

 

[Silly Sausage]

cable ends would be out of the mcb for testing r1. nice try though.

Unless he's testing at a socket!

 

[Englishman]

Unless he's testing at a socket!

Exactly!

Which is what I generally do as it both keep the board tidy and testing rings at the board is a complete nightmare on some boards, especially some of the skeleton boards in mantel units.

 

[Englishman]

cable ends would be out of the mcb for testing r1. nice try though.

Far easier to test at sockets.

And as I said, I've come across high r1s before that have been traced to that. "Nice try" sounds like I just guessed it.

 

[HappyHippyDad]

Unless he's testing at a socket!

Nope, testing at the CU with both line conductors removed from MCB.

 

[Englishman]

Nope, testing at the CU with both line conductors removed from MCB.

If the problem isn't at a socket, break the circuit down in the same way you would a broken leg of ring. Won't be a difficult fault to trace mate.

 

[HappyHippyDad]

Thanks for the ideas guys..

Broken line conductor with 2 appliances either side switched on sounds interesting! If it is that i'll let you know. I'll also look out for the screw on the insulation which sounds quite possible as well. It shouldn't take too long to find as it's just the kitchen and like I said it's all getting ripped apart next week, but I was interested in the possibilities!

Yes Tel.. This is very much a DIY house, the previous owner did most of the electrics to a very poor standard.

 

[ferg]

It's got to be better than the eejit that wired in a house I was at recently.

Apparently you don't need cpc's for lighting.

He did bother for the sockets but G/Y sleeving is clearly optional.

 

[telectrix]

Far easier to test at sockets.

And as I said, I've come across high r1s before that have been traced to that. "Nice try" sounds like I just guessed it.

. sorry about the nice try. was not meant to come across as it seems to have done.