Strange fault

[vad25]

Hello all.

I've got a problem.

Installed 20A radial for 3 double sockets. Main cable go up and then from Wago box 3 cables down to 3 sockets. 2 of them works fine but one shows voltage L-N 236V ( all right) L-PE 135V and N-PE 135V.

Could somebody advise what can be wrong?

Faulty socket I've left disconnected.

Thank you.

 

[NozSpark]

Floating earth?

But then again this would show up when you did your (R1 + R2)

 

[Theorysparky]

is the wago box accessable ???

dead test that socket again(i assume it was done previously before making live)

money is on trapped or damaged cable

 

[benji]

re-check wago connections

 

[Andy™]

dodgy earth connection

 

[vad25]

Thank you for so quick replay.

I'll check joint box and all connection Tuesday.

 

[ProDave]

What testing have you done? It should be elementary to check the earth continuity either with an R1+R2 test, or with a long wander lead back to the CU.

It sounds like you have just wired it and plugged a socket tester in?

With the elementary knowledge shown are you really competent to be fitting new circuits?

 

[vad25]

Dear ProDave.

I've done r1+r2 test before and IR before energising circuit in furthest point everything was OK. When just in case tested Earth fault loop impendance its showed me the fault. This is temporary circuit for kitchen fitters, whole house deenergised and yes it is RCD protected.

My competence to do that kind of job has been assesed by an Inspector from Elecsa this Friday.

Thank you.

 

[NozSpark]

If you had done your pre-energisation (dead) testing correctly then this kind of fault should have shown itself.

As you have a problem you really need to test the sockets continuity from rear terminal to the front!

I had a builder compain about a socket I had installed the other day; all tested out fine, but plug had to be in 100% otherwise it didn't work..

 

[ams13]

Dear ProDave.I've done r1+r2 test before and IR before energising circuit in furthest point everything was OK. When just in case tested Earth fault loop impendance its showed me the fault. This is temporary circuit for kitchen fitters, whole house deenergised and yes it is RCD protected.

My competence to do that kind of job has been assesed by an Inspector from Elecsa this Friday.

Thank you.

Should R1+R2 not be done at all points not just the furthest.

 

[SLIPSHOD & SLAPDASH]

Its a bad earth connection at either the socket or wago, possible the earth sleeve trapped under the socket screw.

 

[ProDave]

Should R1+R2 not be done at all points not just the furthest.

Well you certainly SHOULD go back and test R1+R2 at the "faulty" socket, if not all of them.

---------- Post Auto-Merged at 22:36 ---------- Previous post was made at 22:34 ----------

I've done r1+r2 test before and IR before energising circuit in furthest point everything was OK. When just in case tested Earth fault loop impendance its showed me the fault. My competence to do that kind of job has been assesed by an Inspector from Elecsa this Friday.

Thank you.

So if you are competent, you have found the fault, so trace it and fix it. It just seems so basic that this is a question I would expect in the DIY section.

 

[Doc Hudson]

Should R1+R2 not be done at all points not just the furthest.

Strictly speaking R1+R2 only needs to be done at the furthest point. But polarity and earth continuity should be checked at all accessories. Often R1+R2 is used at all points as part of this testing, especially if the longest cable run is not easily identifiable. This problem does sound like a failure somewhere on the dead testing,

Doc H.

 

[sb_89]

Bashing buttons doing dead tests is one thing , knowing how to carry them out properly and interpret the readings you take is another. It doesn't sound like a very complicated fault to me. re-do your r1+r2 and IR tests again. If that fails maybe elecsa do refunds ?

 

[SPECIAL LOCATION]

Hello all.I've got a problem.

Installed 20A radial for 3 double sockets. Main cable go up and then from Wago box 3 cables down to 3 sockets. 2 of them works fine but one shows voltage L-N 236V ( all right) L-PE 135V and N-PE 135V.

Could somebody advise what can be wrong?

Faulty socket I've left disconnected.

Thank you.

Dear ProDave.I've done r1+r2 test before and IR before energising circuit in furthest point everything was OK. When just in case tested Earth fault loop impendance its showed me the fault. This is temporary circuit for kitchen fitters, whole house deenergised and yes it is RCD protected.

My competence to do that kind of job has been assesed by an Inspector from Elecsa this Friday.

Thank you.

Could somebody advise what can be wrong?

Yes.... I would suggest.. Non Compliance with BS7671 is the fundamental problem...

1/ A fault is when a previously working circuit no longer correctly functions.

Not when something you have just installed never worked!!!

2/ Rushing and cutting corners to energise a circuit before all BS7671 recommended tests have been carried is non compliance.

(could be deliberate or could be incompetence)

3/ Basic guidance can be found starting on Page 190 of BS7671.. 612 Testing..

where...

612.1 states that tests of regs 612.2 to 612.6 where relevant shall be carried out in that order PRIOR to energising a circuit.

612.2.1 {top of page 191} is Continuity of Protective conductors including bonding...

612.3 {page 191} Insulation resistance...

612.6 {bottom of page 192} is Polarity

and

612.6 (III) says wiring has been connected correctly to socket outlets and similar accessories..

So if those steps in BS7671 have been followed.. PRIOR to energising...

then how can the accessories not work when energised??????

:C

 

[vad25]

Thank you all for your answers.Cable was nailed by floor fitters.Sorted it.

The reason why I did not test r1+r2 at each point because it is a new circuit in an empty property I installed week ago (tested it for IR and r1+r2) and owner told me nobody will be on-site before I finished, Sunday night 9:00pm he asked me to connect at least couple of sockets for kitchen fitters,house complete with no electricity, so I connected radial( 3s/o) and tested continuity at the furthest point and energised circuit, when I tested earth loop impendance I recognised this fault, left faulty socket disconnected and today done everything right.

Yes, I understand, it was my mistake and I'm very sorry, but I left nobody and nothing in danger.

Thank you again for your advise and for critics also, everything is very usefull for me.

 

[NozSpark]

Vad,

It's good to hear that you've sorted it.

Whenever I fit temporary sockets I always fit them adjacent to the consumer unit, then if anyone needs power then they can use an extension lead

 

[ProDave]

+1

That's standard practice for me on a new build, as soon as a supply is available, I fit the CU and a radial circuit to a couple of sockets next to the CU.

 

[Theorysparky]

+2

Keeping it by the cu prevents any mishaps

 

[SPECIAL LOCATION]

Thank you all for your answers.Cable was nailed by floor fitters.Sorted it.The reason why I did not test r1+r2 at each point because it is a new circuit in an empty property I installed week ago (tested it for IR and r1+r2) and owner told me nobody will be on-site before I finished, Sunday night 9:00pm he asked me to connect at least couple of sockets for kitchen fitters,house complete with no electricity, so I connected radial( 3s/o) and tested continuity at the furthest point and energised circuit, when I tested earth loop impendance I recognised this fault, left faulty socket disconnected and today done everything right.

Yes, I understand, it was my mistake and I'm very sorry, but I left nobody and nothing in danger.

Thank you again for your advise and for critics also, everything is very usefull for me.

Golden rules from this experience:-

1/ Do not ever believe everything that someone else says... Always assume they are wrong...

2/ Never energise a circuit or part of a circuit unless you have done dead tests that same day..

preferably within 1 hour max of doing dead tests if other contractors are on site..

3/ No mater how tedious a simple checking task may be don't think of skipping it...

4/ If anyone moans at you for checking things correctly before energising, tell em you work in accordance with regs so no one gets injured.

5/ ALWAYS keep this particular job in mind as an example of how assuming one or two things can be a potential problem waiting to trap you.

are you charging them more for fixing their damage to your cables???

:coffee