No R2 reading on ring

[Ben Chitty]

Hi guys, New to testing but been doing installations for about 5 years now. I've come across a problem where the ring I'm testing has no R2 reading, I've split the ring and done a r1+r2 test to find out which leg it's on. Problem is I don't know how the ring was wired. Is there an easy and simple way to figure out where this break is?

Thank you.

 

[PEG]

Hi dude,in addition to your MFT,you need a wander lead,and a notebook and pen.

With a bit of patience,and some tedious M3.5 spinning,you should be able to build up a picture of how the wiring is configured,and where to isolate your problem.

 

[Octopus]

You need paper to draw a map of the installation , then linking one leg at the CU go and take readings at the sockets, looking at the readings, the higher they get the further along the leg you are..... The repeat for the other leg, then you will have an idea where to look.

Sometimes doing a Zs at all the sockets will give you a clue, again looking at the readings ....

 

[Dozer 73]

Once found missing leg , if not snapped off at terminal , good chance a picture hook or screw for shelf etc has gone through cable , seen it many times right above socket , if not could be dodgy joint box

 

[Ben Chitty]

Cheers for the replies guys, Been baffling me all day. The likelyhood of a screw or something going through just the earth is very very unlikely. Checked all socket connections aswell and all ok. Very confused and dreading tomorrow. When testing with a wander lead shall I disconnect just one earth at a time ? E.G. Let's say I've tested 3 sockets, Shall I leave earths disconnected and not touching eachother or should I join back up again? All a bit complicated.



Cheers

 

[Dozer 73]

Cheers for the replies guys, Been baffling me all day. The likelyhood of a screw or something going through just the earth is very very unlikely. Checked all socket connections aswell and all ok. Very confused and dreading tomorrow. When testing with a wander lead shall I disconnect just one earth at a time ? E.G. Let's say I've tested 3 sockets, Shall I leave earths disconnected and not touching eachother or should I join back up again? All a bit complicated.



Cheers

I know why your thinking unlikely but trust me I’ve seen it , how when they were drilling it never shorted , seen t and e with rawl plugs and screws straight through neutral and earths , millimetres either side and the tennant would have had singed eye brows , expect the unexpected

 

[Dozer 73]

Cheers for the replies guys, Been baffling me all day. The likelyhood of a screw or something going through just the earth is very very unlikely. Checked all socket connections aswell and all ok. Very confused and dreading tomorrow. When testing with a wander lead shall I disconnect just one earth at a time ? E.G. Let's say I've tested 3 sockets, Shall I leave earths disconnected and not touching eachother or should I join back up again? All a bit complicated.



Cheers

That’s the problem with ring circuits , you can create these faults almost undetected until an electrician comes to test/ re test

 

[Risteard]

Hi guys, New to testing but been doing installations for about 5 years now. I've come across a problem where the ring I'm testing has no R2 reading, I've split the ring and done a r1+r2 test to find out which leg it's on. Problem is I don't know how the ring was wired. Is there an easy and simple way to figure out where this break is?

Thank you.

Do you mean r2 (as in end-to-end cpc continuity)? Because even with a break on r2 you should still have R2 readings at some or all points unless there are multiple breaks.

 

[Pete999]

Hi guys, New to testing but been doing installations for about 5 years now. I've come across a problem where the ring I'm testing has no R2 reading, I've split the ring and done a r1+r2 test to find out which leg it's on. Problem is I don't know how the ring was wired. Is there an easy and simple way to figure out where this break is?

Thank you.

R1+R2 not r1+r2 is the RFC installed in conduit by any chance?

 

[PEG]

Cheers for the replies guys, Been baffling me all day. The likelyhood of a screw or something going through just the earth is very very unlikely. Checked all socket connections aswell and all ok. Very confused and dreading tomorrow. When testing with a wander lead shall I disconnect just one earth at a time ? E.G. Let's say I've tested 3 sockets, Shall I leave earths disconnected and not touching eachother or should I join back up again? All a bit complicated.



Cheers

Yep,it is a bit complicated,but only if you deviate from tried and tested techniques.
Keeping all accessible conductors disconnected,will allow a certain amount of ease of discerning any interconnection.
Remember,be ready for anything. Cross overs,radial/ring mixed,lollipop and anything in between.
Underfloor can be an isis landmine junction box heaven,so inevitably,it will be the customer's flooring/pocket depth,that will determine the chance of success