Full spread of tests after CU change.

[Guitarist]

I know that many electricians only carry out quick and basic tests after a CU change, but I thought I'd share this with you.
I am a fussy so and so, as many of you already know, so following a CU change I carry out every test imaginable. Having established no shared neutral, good bonding, good IR checks, etc. prior to carrying out said change, I got stuck in to a full spread of testing after installing it....
Was in the process of carrying out an R1+R2 test on every point in the lighting circuit, when I came across an open circuit at a bedroom ceiling rose... Checked switch, connections etc, but no joy. After half an hour in the loft, found the supply to the bedroom lighting joined in a JB but with the cpc ends not connected, just sitting there happily a few inches apart outside the JB, covered in loft insulation.
This is why I would rather be a few quid out of pocket time-wise, than skimp on testing.

 

[Guitarist]

Precisely

I'm glad that you feel knowledgeable and experienced enough to "know better" than the rest of us

 

[Dave 85]

exactly my point is that wouldn't show up on any cable tests thats why relying on end to end tests etc.. wouldn't have shown up this fault. The proper procedure of cross connecting line and earth then testing at EVERY point including BOTH outlets of of a double socket would have revealed the fault. what's not to understand?

Both outlets has never been part of the procedure. Its a wiring test as biff says.

 

[spark 68]

I agree with Guitarist here,
A full set of tests done on a CU change, as I have had polarity reversals Show up during testing (Full RFC tests) at either a 'DIY spur' or in case on one S/O on the ring (DIY replacement ?), slack Neutrals in the S/O but twisted together so it doesn't show on an end to end, the list goes on.

Besides on a CU change, you are signing to say any circuits you re-instate are safe to do so.

 

[Guest55]

exactly my point is that wouldn't show up on any cable tests thats why relying on end to end tests etc.. wouldn't have shown up this fault. The proper procedure of cross connecting line and earth then testing at EVERY point including BOTH outlets of of a double socket would have revealed the fault. what's not to understand?

Thats a good point and i cant disagree with your method.
But the purpose of the 3 step ring continuity test is to confirm connections of the wiring , not to check if accessories are faulty.
A earth loop test at each outlet would have discovered the duff socket without doing the cross connecting.

 

[VoltzElectrical]

Both outlets has never been part of the procedure. Its a wiring test as biff says.

agreed, and it has never really been part of my procedure until recently, and low and behold.... look what I found! How common is it? rare probably. But it does happen, as I have proven. The regs class a double socket outlet as two outlets, so really, and from now on I will, class, and test them as...TWO outlets.

I'm only here to glean from others, and share what i have learned in the field. I have no axe to grind. Let everything be on your own conscience.

Peace.

 

[spark 68]

Thats a good point and i cant disagree with your method.
But the purpose of the 3 step ring continuity test is to confirm connections of the wiring , not to check if accessories are faulty.
A earth loop test at each outlet would have discovered the duff socket without doing the cross connecting.

That is his point, by doing the 3 step test and checking at each S/O would have shown up the fault during dead testing, and presumably corrected before any live testing commenced

 

[VoltzElectrical]

Thats a good point and i cant disagree with your method.
But the purpose of the 3 step ring continuity test is to confirm connections of the wiring , not to check if accessories are faulty.
A earth loop test at each outlet would have discovered the duff socket without doing the cross connecting.

Can't disagree Biff, but speaking for myself and many others surly, when required to provide a Zs from a RFC, who tests at EVERY outlet? I didn't used to. Did this time and found this and now forever will.

Peace

 

[Guest55]

That is his point, by doing the 3 step test and checking at each S/O would have shown up the fault during dead testing, and presumably corrected before any live testing commenced

Hmm , thats debatable as thats not the purpose of the ring continuity test.
And as the fault existed anyway while the installation was energised , discovering the faulty socket during live tests is hardly a major threat / risk / inconvienience.
But im off to bed now lol.

 

[spark 68]

Hmm , thats debatable as thats not the purpose of the ring continuity test.
And as the fault existed anyway while the installation was energised , discovering the faulty socket during live tests is hardly a major threat / risk / inconvienience.
But im off to bed now lol.

Not having a go at anyone Biff, each to their own, and if they are happy signing stuff off untested then that is up to them.

There was a thread on here not so long ago about a plumber who was killed due to a miswired socket (polarity), and the sparks involved ended up in court, I would rather do the tests properly and sleep easy that's all.

I would just like to point out the testing and minor fault fixing should be factored in to a CU change price anyway, majors are a different matter and should really be picked up at the initial survey/quick test stage.

As I say each to their own.

 

[brucelee]

Hi mate is this job AT MY BRUVS as i am finding similar probs to you
my tutor at college asked me why i tested at both sides of doubles i said because they are both outlets and also value can be significantly higher as i have found
continuity on lighting some switches were giving readings with it switches off

started of at somewhere in the region of well over 4 ohms the meter wouldnt give a constant reading it was as high as 6 some of the time
LOW IR
shower 6mm OK at 45A dp switch feeding 230v fan zone 1 1.0mm / also feeding a FCU for Old C/Heating supply
spurs of spurs
mutiple connection blocks no tape loose connections
hidden JBs with loose connections
rodent damage hidden under a board were i was looking for a hidden JB for landing and loft light were it was giving a high continuity reading
bonding to water after branchwork High readings before and other side
Ip ratings not met on newer single rcd board
circuits still connected in old wylex 4 way going nowhere and about 4 circuits in each
downlights in kitchen 2 supplies switches at side of each other 2.5mm feeding 1.0mm again chockblocks
twiisted Ns not in terminals at sockets
twisted cpcs not in terminal at socket
metal back boxes protruding from wall
grommets missing
no sleeving on earths
switch wires not identified
sockets are suspect to say the least think ring is in JBs most sockets downstairs have 1 cable so spur of JB no prob if not ideal
then spurs of spurs
some sockets had ok reading at one outlet of double socket and at other as much as 2-3ohms
some wouldnt switch off
step 2 and 3 readings are nowhere near within 0.05ohms of each other
cracked sockets and switches with heat damage
every time i found a fault i would repeat the test and slowly but surely reduce the continuity readings to a more acceptable reading and increase the IR


mate i could go on so now like you I test evrything borrowed neutrals even between the disconnected NOW DEAD circuits and the remaining circuits to see if there is continuity still and IR between them


and have condemned the lights and told him unless he lets me under floorboards to have a look its staying locked off as i still have a L-N 0.14 to 0.27 Meg and yes evrything is unplugged disconnected removed linked out
this wouldnt show up if i just tested with L&N joined to earth then i got a reading of 80+M/ohms

I suspect the lighting problem stems from the 10K kitchen he had done
its not worth 1K
best bit granite worktops the rest any muppet could chuck together
they just slung cables behind cupboards and even behind fridge High level double with cables jsut dangling down and disappearing behind cupboards he could of at least used cable clips for 10k

the transformer for pelmet selv lighting is sitting on top of the freezer with untaped chock blocks for the connection point sitting along side the transformer

anyway woooden floors newly laid carpets coming up upstairs and if its bad i will give him the good news lets rewire the lights and sockets LOL and get some chases in the plastering he had done other year lol

 

[brucelee]

Have any of you seen the elecsa newsletter SPARK
fatality prompts warning to installer community after the death of a young mother
and are urging electricians to follow correct procedures after unearthing a catologue of failings
in a new block of flats in west bromwich
and cutting corners when testing as the guy ended up in the dock before the man

 

[spark 68]

Have any of you seen the elecsa newsletter SPARK
fatality prompts warning to installer community after the death of a young mother
and are urging electricians to follow correct procedures after unearthing a catologue of failings
in a new block of flats in west bromwich
and cutting corners when testing as the guy ended up in the dock before the man

Not yet, it is in the pile of junk mail I get lol.

 

[Dave 85]

I'm glad that you feel knowledgeable and experienced enough to "know better" than the rest of us

Look pal, if you get some kind of peverse saitisfaction out of treating every job you ever do as a rerun of your college testing and inspection assessment then thats cool, I got no problem with that, but Im too busy trying to keep all my clients happy and earn a decent living, to be spending hours of my life trying to satisfy irrational urges that I dont actually have. I have ample confidence in my own judgement.

 

[brucelee]

LOL
basically they are saying he was cutting cormers so issuing fake EICs which is fraud and negligence as well as idiotic and dangerous etc
a test sheet was signed off without proper checks being completed one was the insulation resistance test is often done sometime before the installation is completed and the system as whole tested to get power for trades and should be done again once everything is complete he was just saying it had been done
the eic is what they will use to find and incriminate you if anything is wrong with the system

she had a leak and was mopping up leaking water from a faulty heater it doesnt go into much detail but think they are after taking action against the person who signed etc

it wasnt jsut her flat it was the whole block of flats that had issues

 

[spark 68]

Look pal, if you get some kind of peverse saitisfaction out of treating every job you ever do as a rerun of your college testing and inspection assessment then thats cool, I got no problem with that, but Im too busy trying to keep all my clients happy and earn a decent living, to be spending hours of my life trying to satisfy irrational urges that I dont actually have. I have ample confidence in my own judgement.

It is not that Dave,
I was T&I ing long before I got my 2391 or registered, but when you have been testing for any length of time, and come across some of the naughty faults that I, and probably others on here have, you learn to test properly, and more important the reasons why.
Even more so, when my name is on the documents.

Iam not meaning to come across holier than thou, but some of the downright dangerous stuff I have come across just reinforces all the more the reason to do it, some things make me shudder to think what could have happened.
It can be all to easy to miss things, and at best you will get a call back, at worst... in the dock.
I don't want anything to ruin my reputation that's all.