How do you check circuits in a house after installing a new fuse box?

[Gina]

I will let you all know what we sorted.. I will take your comments onboard and ask the electrician to do / check what's mentioned here!
I start liking wires now..

 

[Gina]

It is possible to trace and check the cables with the floor down, it may be a little more difficult to replace if damaged part at through.
A person who is good at determining what the readings on the meter are saying is required, if the electrician only records the results but does not understand them then they are not best placed to advise.

Many faults of this mature are a result of human error or faulty appliances, unless you have a vermin problem.

This circuit got 4 plugs in 2 different bedrooms and one fusebox in upstairs cupboard in which there are the wires connecting this heating zone controller device.
Luckly the fusebox we could take it out completely and plug the wires from the heating 2 zones controller at a 2 sockets plug next to the fusebox.
So, the fusebox upstairs in the cupboard, independent to the consumer unit new installed, is disambled/out.
But I wonder now, the tripping came from the one bedroom plugs. If we disconnect those 2 tripping plugs complety, could it be possible that the circuit will be working fine for the next 2 plugs in the other bedroom? Meaning the fault could have been the 2 plugs which tripped a lot in the one bedroom?
Luckly again we have a third plug on a different working circuit in this bedroom, but we would need one plug for the second bedroom.
P.S. The electrician measured the wires with his Megger tester, and ground one was 99 or so. He said it should be close to zero as the neutral and live wire. He should return sometime soon.. but from his point, that circuit is faulty and cannot be used, unless tracked and fixed, which means taking boards out..

 

[Gina]

makes you wonder if it's a cable just under the floorboards, or possibly a nail just touching the cable that moves with people walking up and down.

As it is suppossed to be a ring, it should be possible to identify and isolate the faulty length of cable and split the circuit into 2 separate radial ccts, RCBO will need changing to 20Amp and not left on 32Amp.

expand...

This circuit got 4 plugs in 2 different bedrooms and one fusebox in upstairs cupboard in which there are the wires connecting this heating zone controller device.
Luckly the fusebox we could take it out completely and plug the wires from the heating 2 zones controller at a 2 sockets plug next to the fusebox.
So, the fusebox upstairs in the cupboard, independent to the consumer unit new installed, is disambled/out.
But I wonder now, the tripping came from the one bedroom plugs. If we disconnect those 2 tripping plugs complety, could it be possible that the circuit will be working fine for the next 2 plugs in the other bedroom? Meaning the fault could have been the 2 plugs which tripped a lot in the one bedroom?
Luckly again we have a third plug on a different working circuit in this bedroom, but we would need one plug for the second bedroom.
P.S. The electrician measured the wires with his Megger tester, and ground one was 99 or so. He said it should be close to zero as the neutral and live wire. He should return sometime soon.. but from his point, that circuit is faulty and cannot be used, unless tracked and fixed, which means taking boards out..

 

[binky]

This circuit got 4 plugs in 2 different bedrooms and one fusebox in upstairs cupboard in which there are the wires connecting this heating zone controller device.
Luckly the fusebox we could take it out completely and plug the wires from the heating 2 zones controller at a 2 sockets plug next to the fusebox.
So, the fusebox upstairs in the cupboard, independent to the consumer unit new installed, is disambled/out.
But I wonder now, the tripping came from the one bedroom plugs. If we disconnect those 2 tripping plugs complety, could it be possible that the circuit will be working fine for the next 2 plugs in the other bedroom? Meaning the fault could have been the 2 plugs which tripped a lot in the one bedroom?
Luckly again we have a third plug on a different working circuit in this bedroom, but we would need one plug for the second bedroom.

Sounds like a knackered socket(s) in the bedroom, or incorrectly wired sockets which could possibly explain why your sparky didn't find a fault as cable testing doesn't necessarily reveal such a fault unless every point on a cct is inspected. Only testing/fault finding will answer your question properly.

 

[SPECIAL LOCATION]

Tracking cables is too late now as we fitted new floors...

When trying to locate unknown cable faults I never start with lifting floors...

Basic steps I would do are generally along the lines off:-

1/ Draw a simple sketch plan layout of the property..

2/ Turn off every other circuit except for the suspect faulty circuit..

3/ Walk around the whole property making a note on your sketch plan of every accessory position that still has power to it..

4/ Re energise all the good circuits, and turn OFF and disconnect all accessories, lamps etc from the suspect circuit..

5/ Disconnect the physical conductors from the consumer unit for the suspect circuit..

6/ Double check any relevant ring continuity values.. and Insulation resistance values..

7/ Assuming there is not a direct dead-short across all three conductors, put a temporary connection between two conductors, L-N or L-E or N-E, at the CU, (e.g. with a level Wago), then go around to every accessory position and measure the continuity between the conductors you have joined.

8/ Note on your sketch plan the values you have measured..

9/ From your readings and the layout sketch, you can get a rough idea of the cable route, (due to basic laws of physics with resistance increasing the further along a cable that you test). Its a bit like a join-the-dots picture, where the numbers will get consecutively higher the further along the circuit that you go..

10/ Obviously consideration of possible, branches/spurs due to unknown junction boxes should be considered..

11/ Once you know a basic layout of the circuit wiring you can start splitting sections off to narrow down between which accessories the actual fault(s) lies.. And thus where cables may probably run and/or if you then need to consider lifting floor boards to find junction boxes or replace sections of cable?

It can be time consuming..
BUT, IMHO its better than randomly lifting floorboards that may not need to be lifted!!

At the start of last year, I was investigating a near direct short between N & E on a socket circuit..
that the previous electricians had left connected to a Non-RCD protected MCB..
It took me approx two and half days labour, to find the fault, and replace a section of damaged cable between the CU and first socket in lounge!

NO floorboards were lifted until we had narrowed down where the probable damaged cable was..

What you need first is some accurate inspection and testing.

Your problem sounds to me like the to far to common problem with some electricians eager to get work..
But they forget to quote for time needed investigating & resolving existing faults that the old Consumer unit cannot detect.

As mentioned earlier, the physical layout of your CU looks quite good..
So maybe you electrical is good at installation and connecting work...
But struggles with testing and fault finding? (which is not uncommon!)..
OR... is just very busy with loads of other jobs and knows that fully investigating you problem is not going to be a quick half-day find & fix!!!

 

[sirsparkabit]

If you had tripping before floors went down ,it makes me wonder why flooring went ahead?.
Seen many pressure faults occur with flooring laid on top of old floorboards, it happens! .
Please try and be nice to your spark and he to you i hope , see if he can be worth his salt and trace the fault . Its not rocket science and would be wrong of us to assume he is not competent as only you and he know the full story.
No offence intended or implied to either party...

 

[Gina]

If you had tripping before floors went down ,it makes me wonder why flooring went ahead?.
Seen many pressure faults occur with flooring laid on top of old floorboards, it happens! .
Please try and be nice to your spark and he to you i hope , see if he can be worth his salt and trace the fault . Its not rocket science and would be wrong of us to assume he is not competent as only you and he know the full story.
No offence intended or implied to either party...

He came and checked the tripping before the floors went down.. He said is all good. He had other small bits on his list to fix, from the day he teasted the new CU.. I never imagine the situation will turn like this. He could have test it properly, as I am sure at this day, having other bits he just did the quick test with the plug in 3 lights socket and he saw 3 green lights, assumed it's all good. He was first contacted by us in the beggining of November.
When we told him about the tripping again while floor fitters were here, he came but the floors were covered already where the wires would go.. he tested at the CU and I went to see what is he doing and showed me the L and N were 0.4 or so, close to zero, so were good.
But the earth was showing 99.
I am sure if he tested this way before, he would find same numbers and the difference is, he would have access to the circuit as the old floors would be ok to be lifted.
Than he could have tell us this circuit needs changed.
Thank you everyone! I am greatfull for time and advice given! I really didn't expect this much involvement.
I will wait and see when he is back what we will do.
I will take notes from advices on this thread and also ask him to test as other sparks adviced.
And I don't look for war, but solutions. Just worried for the rest of circuits now.. anyway.. bad luck as many other stuff since we moved here, where traders did it wrong..

 

[Murdoch]

Floors down after initial tests!

I'll say this again - communicate with the spark, WE are only speculating.

 

[Gina]

Floors down after initial tests!

I'll say this again - communicate with the spark, WE are only speculating.

We are consumers, we employ traders to do their job.
The electrician should have done his, especially he knew we will have floors done. When you say you finished the job and you will issue a certificate, what we should have beed waited for?! Apologies but I don't understand the phrase
"Floors down after initial tests!" We were not told to wait with the floors!
We approached him almost 3 months ago, he took his time to come over and we had patience waiting.. I mean we did not employ him a week or 2 before the floors.. we got the house back in May. People try to fix their house and move on with their lives, don't they? Or at least that was our hope.. living in a mess is noone's desire. And we just do the essentials, not luxury, extentions etc.

 

[Murdoch]

We are consumers, we employ traders to do their job.
The electrician should have done his, especially he knew we will have floors done. When you say you finished the job and you will issue a certificate, what we should have beed waited for?! Apologies but I don't understand the phrase
"Floors down after initial tests!" We were not told to wait with the floors!
We approached him almost 3 months ago, he took his time to come over and we had patience waiting.. I mean we did not employ him a week or 2 before the floors.. we got the house back in May. People try to fix their house and move on with their lives, don't they? Or at least that was our hope.. living in a mess is noone's desire. And we just do the essentials, not luxury, extentions etc.

You have previously suggested the spark IS coming back. If not then you need to find another

With respect to certification and part P - have you received anything?

 

[UNG]

When we told him about the tripping again while floor fitters were here, he came but the floors were covered already where the wires would go.. he tested at the CU and I went to see what is he doing and showed me the L and N were 0.4 or so, close to zero, so were good.
But the earth was showing 99.

So, close to zero readings would be ok for continuity checks but what Insulation Resistance checks were done as these need to be above 1MΩ as an absolute minimum and close to zero would be a circuit that couldn't be connected

From what you have posted to date I have some doubts as to the ability of the the electrician you are using

 

[Gina]

You have previously suggested the spark IS coming back. If not then you need to find another

With respect to certification and part P - have you received anything?

He didn't issue anything yet.
He visited us at beggining of Novemer to talk about the job and look at the old fuseboxes.
He than wrote us a whatsapp message with costs for new consumer unit and some bits we suggested we would like to do.
A few weeks later he came and installed 12 spot lights.
At a time later not sure approx 2 weeks later he came for the consumer unit and other bits.. he started with other bits first, like changing a few sockets and switches, not because were not working, we wanted matching ones but just a few, we didn't want to change all, just a few whites in metal finish to match others downstairs. Not sure what the electrician did for 2 days or let's say 2 days but a few hours a day, not a full 7 hours or what's a working day for electricians? He changed Earth for the new boiler and for the cooker. He installed a new socket for the cooker. As well another 4 spot lights in the bathroom.
The third day consecutive to other 2 he started the consumer unit, which he finished the next day..
He than came again to test the CU and checked the bits around the house, the sockets and lights in the ceiling (not the switches) for ground faults as he said he saw some sockets without the ground/earth. One socket had inversed wires. So, after christmas and New Year he came again to fix these as he noted them on his phone. At that point we told him about the tripping. What he did that day about testing the tripping, I believe he didn't as somehow he got carried away with other few bits and I think he just used his socket plug device with 3 lights for testing the tripping sockets. He gave his ok and next step was certificate.. I told him to write it when he can, not necesary that evening or next day.. but the week went and the following week the floor guys came. It never crossed my mind to plug the vacum cleaner again in those sockets after he left! For that I blame myself. But when the floor guys used those 2 sockets again tripping.
Than I told the electrician, but he came and the floor installers really moved quickly, they covered the area.. When electrician came he checked, showed me the numbers L and N were ok, clise to zero, the E or ground one was 99. He than said the circuit is bad. But surely if he did same testing before he would have found same numbers! Just a week before, if he would .. if.. if.. doesn't work anymore. We cannot live with 'if'. So, all in all the electrician was by us 8 times! I believe he wants to finish this circuit and the lights in the landing/ hallway, as they went off as well.. he tested the electricity in the lights and said there is electricity, so he doesn't know what could be, but he went in the loft to check the cables and could not access it, he said when he will come back he will cut boards for the access..
Luckly we did not do the downstairs, just upstairs, but any lights from downstairs will be problematic to fix as the new floor boards are upstairs.
When you encounter one problem you start wondering what else could be there? Praying this is the only one/ ones, with the landing lights.
We will have to get the job finished with this electrician (as if another electrician than anything happends they would blame each other), get certificates (hopefully he will issue them, cz I am not sure if he will now thinking there could be issues; don't know if providing a certificate will be a responsability on him later on in case something else comes up/goes wrong!) and than get another electrician to check the electricals / EICR...

 

[Gina]

UNG, what you describe, "So, close to zero readings would be ok for continuity checks but what Insulation Resistance checks were done as these need to be above 1MΩ as an absolute minimum and close to zero would be a circuit that couldn't be connected"
I think the electrician doesn't know! I will ask him when he comes! He may know installing things but not checking circuits. If he wanted to do a quick thing, he just checked like I could check really!
I am going to print all options/advices here and discuss with him.
I need to study electricals.. get a book and read as it seems I cannot trust ones job!
I did the same for other jobs in the house! Why do we need to worry and consume time with finding the right way because some traders don't do it right?
Out of curiosity, how much a consumer unit as above would cost installing, testing and certificates? Before there were 4 fuse boxes, he made it in one consumer unit. I will attach photos of before CU.
I just attached the previous fuse boxes, 4 in the 3 photos and one more photo of the cupboard and their positioning. He started taking wires out in the full picture, but the fuse boxes and wires were neatly done when they were done.. I am transparent so, in London, south est London, Bromley area if that makes a difference, any estimates of such a job, changing new CU and test and certificate.

 

[Murdoch]

Do you owe him money?

 

[Gina]

UNG, hat you describe, "So, close to zero readings would be ok for continuity checks but what Insulation Resistance checks were done as these need to be above 1MΩ as an absolute minimum and close to zero would be a circuit that couldn't be connected"
I think the electrician doesn't know! I will ask him when he comes! He may know installing things but not checking circuits. If he wanted to do a quick thing, he just checked like I could check really!

Do you owe him money?

No, we paid him everything he requested. We paid including the testing and certificate of the CU. So, in fact we paid more as he did not provide certificates and the testing.. that's why I am here.. as he said he tested, but only he knows how..
I just asked about estimates here to see if he thinks that what he requested was including just very basic checks... but basic checks don't work with giving a certificate, right?
He initially would write on whatsapp £850 for CU with certificate, testing.. he also mentioned about other stuff, quoted bits, like how much for spot lights, changing a socket, a switch, installing light chadellier.. So, he wrote this bits on a whatsapp message. We paid the spot lights, but than when he returned for the rest of the work, he worked more or less hours during 4 days (really, some days would be half day) and he asked us 4 full days of work, plus materials. We paid, but initially on whatsapp he said £850 for CU with material, testing, certificate, after he finished the CU he said it would be half more over £850 as he just saw a forth fusebox under the left shelf (there where some boxes there, maybe that's why he didn't see this one fusebox). I attach the photo of this last box he didn't see... So, with this one, he would quote £1275, that includes the CU and RCDS. Is this cheap for him to not do the proper testing?

 

[Murdoch]

Well, he’s got your money …,

Has he claimed to be a member of the NICEIC or NAPIT ?

 

[Gina]

Well, he’s got your money …,

Has he claimed to be a member of the NICEIC or NAPIT ?

He was recommended by another trader (I will not detail about that as well). we didn't check qualifications.
I added/answered more to my previous answer regarding the payment.

 

[Murdoch]

You need to ASK HIM about testing and the certification

 

[Gina]

You need to ASK HIM about testing and the certification

what he will say... let me guess, "yes, I did all the testing, bla bla bla" What do we know? The reality.. Certificate hopefully will follow. I will be back when or if that happens. All the best to everyone, I know we don't live in a perfect world.

 

[Murdoch]

what he will say... let me guess, "yes, I did all the testing, bla bla bla" What do we know? The reality.. Certificate hopefully will follow. I will be back when or if that happens. All the best to everyone, I know we don't live in a perfect world.

You really need him to come back to resolve the tripping issues