EICR Ring Final Circuits

[soulman]

Hi,

While conducting an EICR on a RFC, end to end test is carried out on each conductor and a Zs at each socket outlet, the Zs always varies a little due to the resistance of the socket. So how on a periodic are you to determine whether there is a spur off a spur, as crossovers etc are not normally carried out. The reason i'm asking is recently i have done remedial works for EICR that someone else has done and found spur off spurs (one was actually 5 sockets into an extention) Yet this wasn't picked up. I have also asked experience electricians and got different answers. You are signing to state that the installation is safe, so this has got me thinking.

Cheers

 

[SPECIAL LOCATION]

Hi,While conducting an EICR on a RFC, end to end test is carried out on each conductor and a Zs at each socket outlet, the Zs always varies a little due to the resistance of the socket. So how on a periodic are you to determine whether there is a spur off a spur, as crossovers etc are not normally carried out. The reason i'm asking is recently i have done remedial works for EICR that someone else has done and found spur off spurs (one was actually 5 sockets into an extention) Yet this wasn't picked up. I have also asked experience electricians and got different answers. You are signing to state that the installation is safe, so this has got me thinking.

Cheers

get the nit picking bit out the way first...

1/ You are conducting a PIR and reporting it on an EICR NOT conducting and EICR!! headbang

2/ BEFORE commencing any PIR work you agree with the client the extent and limitations of the inspection...

3.6 Page 61 GN3..

The composition of ALL circuits should already be provided..

if you don't have this info..

You need to discuss with the customer how much time & money you are to invest into identifying the circuit compostion..

rings radial spurs ect...

AKA the extent of your investigations and testing.

:coffee

 

[steptoe]

as crossovers etc are not normally carried out

what do you mean by that?

L1 to E2 and L2 to E1 ?

if so then IMHO YES, they are normally carried out.

---------- Post Auto-Merged at 00:05 ---------- Previous post was made at 00:02 ----------

You are signing to state that the installation is safe

NO you are not, you are signing to say your findings are a statement of fact on the day you carried out your test,

either 'SATISFACTORY' or 'UNSATISFACTORY'

whichever you find it to be.

 

[soulman]

Cheers for that, i was under the impression that crossover tests were not performed during a PIR. Only during Initial verification.

 

[steptoe]

soulman you perform whatever tests are necessary to fill in your cert, within the extent of installation covered and the limitations that you and your customer agree on,

 

[SPECIAL LOCATION]

Cheers for that, i was under the impression that crossover tests were not performed during a PIR. Only during Initial verification.

You can decide whatever tests you deem appropriate 3.10.2 pg 73 GN3!

Guinness

THERE IS NO SUCH THING AS A STANDARD FORMAT FOR A PIR!!



---------- Post Auto-Merged at 00:16 ---------- Previous post was made at 00:14 ----------

Steping tow is pushing and shoving again ADMIN!!!

:_| :_| :_| :_| :_|

can we go and let his tyres down please???

 

[soulman]

Sorry it's the way i have been taught i was taught on a pir to only do r2, end to end and a zs at each socket outlet, Also the electricians i have worked with have never crossed over, also the niceic dvd on periodic inspection i watched recently also indicated that crossover test were not neccessary thats what confused me.

 

[steptoe]

can we go and let his tyres down please

you could perm any 3 out of 5,!

---------- Post Auto-Merged at 00:30 ---------- Previous post was made at 00:26 ----------

Sorry it's the way i have been taught i was taught on a pir to only do r2, end to end and a zs at each socket outlet, Also the electricians i have worked with have never crossed over, also the niceic dvd on periodic inspection i watched recently also indicated that crossover test were not neccessary thats what confused me.

I mean this in the best possible way,

but this is one of the many reasons that persons without the knowledge or competence should NOT be carrying out PIRs,

now, before anyone jumps on their soapbox, the OP is not alone in this, but far far far too many people are doing PIRs without the very basics of knowledge,

IMHO a PIR is a much harder job to do than an initial verification.

How can anyone realistically do a pir on a (even 10year old property) without having a working knowledge of the previous version of the regs?

never mind even knowing how to test properly?

 

[springcrocus]

Playing Devils advocate here, there is a school of thought that suggests that disconnecting conductors during a PIR may introduce a fault that didn't exist prior to the event. Once you reconnect, you then have to retest to ensure that the work you have performed is sound.

 

[steptoe]

what work?

and what fault could you introduce by performing your tests correctly and reconnecting correctly?

 

[kme]

Albert - I think he`s referring to the old chestnut of disturbing the wiring, and not re-inserting a conductor properly; or failing to tighten the terminal up.

SummerSunflower - Exactly the same argument exists for releasing a socket or switch faceplate from the wall, to visually inspect the wiring behind it. In doing so, (or when refixing), you could trap a conductor, or cause a break within the back box, etc, etc. Which is why tests are done in a specific order. IF the correct proceedure is followed; any of the above scenarios would be discovered..

Besides - what`s the alternative? Don`t test it because you might not put a wire back properly? (read as : don`t test because you can`t do your job properly).

So don`t drive your car, because it won`t break down if you aren`t driving it!

That argument doesn`t hold much water, I`m afraid. Yes, we`ve seen consumer units with a busbar that has missed the MCB terminal - that isn`t a accident, its poor workmanship.

Same goes for your Devils advocate position.........people are human - they make mistakes - they try to do things they really don`t have the skills for.

Everybody makes mistakes, but if you follow a careful, structured line on your testing procedures, you minimise the risk of such problems occurring.

KME

 

[davetheglitz]

On domestic jobs I have found that the crossover test is generally inconclusive on EICRs due to poor connections on sockets and the short length of a spur . Wiggle the plug in the socket and you get different readings - certainly enough that you can't tell whether it's a spur or not.

 

[soulman]

Hi Thanks for the replies chaps. With regards to steptoes post, and with the greatest respect I appreciate what your saying, but the periodics were carried out by experienced electricians. It is impossible for electricians to know all previous regs, and as the periodic is to the current regs if something was unsafe, it is unsafe regardless of the regs. Also if i was to come across something i wasn't sure about, forums like this and other electricians are always willing to help. i ask the question because i want to learn, it has niggled at me for some time and the advice you receive is always conflictng. I suppose the lesson here is always cover yourself spend a bit of extra time. One electrician i asked said spurring off a spur would never really cause a problem that is why we only do end to end, he adviced me to watch the niceic dvd. Also a college lecturer once told me during a pir, the majority of problems with an installation is discovered during the inspection process and not through testing.

Davetheglitz that is exactly what i am talking about.

 

[ProDave]

The point about knowing previous versions of the regs is to stop people condemning an installation as non compliant. If it complied with the regs when it was installed, and you are not modifying it, there is no requirement to bring it up to current standards, but it would appear some people are forcing unnecessary CU changes on their customers because they either don't know that, or don't know what the previous regs said so don't if it was compliant or not.

And your "experienced" electrician saying a spur off a spur would "never really cause a problem" is just plain wrong. It's easy to see a situation where two high powered loads are plugged into both spurs and end up overloading the cable.

If you suspect you might have a spur from a spur, then open up the accessory in the middle of that suspected "spur chain" remove the wires from it and check for continuity. If you get continuity L-L etc then it's not a spur, but part of a ring. If you get no continuity, then it's either a multiple spur, or a broken ring.

I would expect end to end testing of a ring final to be something everybody did as part of a PIR, and since you have already undone the connections to do that, then also doing the figure of 8 test (or whatever you call it) is simple enough and does not add any additional risk of putting it back with a loose connection.