Cross link

[swift2]

Good Evening All, I would like to pick your brain again please.
Scenerio being a test on a Ring final circuit. I completed the end to end readings they were fine, came to the cross link p1 to e2 p2 to e1.
There are eleven points on the circuit all of them came up fine apart from the last three, the readings where of 725 to 750 ohms.
I couldnt believe it so I opened up the face plates and took the readings with the probes on the screws still the same. Then I have unscrewed the cables out of the sockets thinking it could be some faulty sockets and took the readings again, they didnt change.
I do realise that there is a major fault on that side of the circuit, and will check for continuity between phase and earth without the crosslink.
Lucky for me there is nobody living there, so I could leave it isolated, however my question is if somebody was living there how would you go about it ?
I have heard you cant condemn the sockets, only advise the customer not to use them ?
If you were to blank them off with blank plates and crimp the cables or wago them, would that still not be dangerous as it is a Ring final circuit and them cables would still be in use ?
Last of all I might be missing something very simple here but why am I not getting high readings all the way around ?
Thank you in advance.

 

[flyingsparks]

Sounds like the last three are all on one spur. Is the appliances plugged in, which is where your 750 ohm reading is coming from?

 

[swift2]

Thank you for your reply. No there is no appliances plugged in, fuse spurs are in the off position too. There was a fuse spur for the boiler that I thought could have been connected the wrong way around, so I then disconnected the cables from the fuse spur and tested on the cables.

 

[RF Lighting]

Sounds like the three duff sockets are either a spur off a spur off a spur or a ring within a ring also known as a figure of 8 circuit.

You can cross link neutral to live and then neutral to earth and repeat your continuity tests to work out which conductor is high resistance.

It will probably be at a joint where these three sockets are supplied from, but how to find that joint is another story...

This shows why testing is so important and good on you for actually knowing how to test a ring circuit properly.

 

[swift2]

Thank you for your reply, if there is a joint it is in the partition wall or under the tiles in the bathroom above. Bathroom floor is of limits, I would be allowed to have a go at the wall though. Hopefully I can find it before it comes to that. I will go for the figure of eight and see what can be done. Thank you again !

 

[JohnW2]

Sounds like the three duff sockets are either a spur off a spur off a spur or a ring within a ring also known as a figure of 8 circuit.

If it were the latter, I would think that it would need at least two faults to result in what the OP is seeing, so a spur situation would seem (to me) to be more likely. If it's a line of spurred sockets, presumably (as you suggest) there must be a problem where the first of these originates from the ring - which, unless the OP's unlucky and it happens in a hidden JB, is likely to be at one of the ('accessible') sockets - and hence hopefully fairly easily findable?

This shows why testing is so important and good on you for actually knowing how to test a ring circuit properly.

Indeed so,

Kind Regards, John

 

[swift2]

Thank you all for your help, appreciated !