CONSUMER UNIT CHANGE

[waza123]

hi new to site i just wondered im changing consumer unit for new one on tt system and there is a meter then tails to a volt operated earth leakage circuit breaker then from that to my consumer unit if my new board is dual rcd can i just get rid of the elcb also no earth rod well i cant find one there is a small 4mm earth cable in wall but has been cut of what size is required is it 16mm from cu to earth rod

thanks for your replys

THE VOELCB IS 60 AMP WITH BIG YELLOW TEST BUTTON

reason for change is elcb buzzes when i plug washing machine in also is very old and cracked and has no cover { very dangerous i know }

 

[flameport]

If you have to ask these very basic questions, why are you attempting this work?

 

[mikhailfaradayski]

hi new to site i just wondered im changing consumer unit for new one on tt system and there is a meter then tails to a volt operated earth leakage circuit breaker then from that to my consumer unit if my new board is dual rcd can i just get rid of the elcb also no earth rod well i cant find one there is a small 4mm earth cable in wall but has been cut of what size is required is it 16mm from cu to earth rod

thanks for your replys

THE VOELCB IS 60 AMP WITH BIG YELLOW TEST BUTTON

reason for change is elcb buzzes when i plug washing machine in also is very old and cracked and has no cover { very dangerous i know }

Blimey,

I'm no english teacher, but i think a few full stops or commas might help here.

 

[1john]

How will you know that the RCD's will trip out in time. How will you verify the Ze of the newly installed rod?

 

[M4]

I'd run 16mm to the rod and lose the elcb

 

[securespark]

Depending on installation conditions, the CSA of the conductor to the rod can be as low as 2.5mm2.

 

[ban-all-sheds]

• For a circuit to supply a given load, how would you go about deciding what cable and protective device to use? (No, you can't just copy what's there because it's going to become your responsibility and what's there might be wrong.)
  
  
• Do you know which circuits can be ring finals and which cannot, and what the advantages and disadvantages of each are? (No, you can't just copy what's there because it's going to become your responsibility and what's there might be wrong.)
  
  
• How do you calculate maximum demand and how can diversity be used?
  
  
• Can you correctly identify all components and connections of a circuit by method of testing or otherwise? In doing so can you identify or recognise anything wrong or dangerous with the circuit? You cannot assume that what's currently installed is OK, and you need to check it before starting work.
  
  
• Do you understand how the way in which cables are installed affects how much current they can carry? (No, you can't just copy what's there because it's going to become your responsibility and what's there might be wrong.)
  
  
• Where cables need to be joined, how should this be done / not be done and in what circumstances are different methods acceptable?
  
  
• Can you identify extraneous conductive parts, and do you know the requirements for main and supplementary bonding of them?
  
  
• Which circuits should be RCD protected?
  
  
• How do you propose to isolate your supply so that you can connect up your new CU?
  
  
• Do you know what tests you would carry out on the installation - what sequence you'd do them in and at what point you would energise the installation, and for each test do you know what is being measured, why it is important, how you would carry out the test, and with what equipment, and what sort of results you would expect to get if everything was OK?
  
  
• When you apply for Building Regulations approval what do you plan to say will be the way you'll comply with P1?
  

 

[bernardgreen]

reason for change is elcb buzzes when i plug washing machine in also is very old and cracked and has no cover { very dangerous i know }

What is old and cracked, the breaker or the washing machine.

Obviously you have an earth of some sort to the elcb otherwise the elcb couldn't be buzzing on the excessive earth leakage from the washing machine.

But from the questions you ask seems apparent that you do not have the necessary knowledge to change the consumer

{ very dangerous i know }

Changing a consumer unit can also be very dangerous if done without the proper knowledge, both while changing it and afterwards when in-correctly installed safety devices do not operate when they need to operate in order to protect the system and /or people in the building.

 

[dingbat]

I agree with all the sentiments expressed here.

The OP should not even be considering doing this work himself.

(And VOELCB should have been replaced decades ago!)

 

[OwainDIYer]

Maybe it's Ufer earthed

 

[waza123]

i thought this site was ment to give helpfull advice.

im very dissapointed in this site

it was just a bloody question calm down everyone just

 

[ban-all-sheds]

i thought this site was ment to give helpfull advice.

It is, and the advice you have been given is helpful.

im very dissapointed in this site

Being disappointed because the advice you got wasn't what you thought you should get is understandable, but the fault lies with your mistaken opinions about what constitutes good advice, not with the site.

it was just a bloody question calm down everyone just

OK - so please calmly answer these questions:

• For a circuit to supply a given load, how would you go about deciding what cable and protective device to use? (No, you can't just copy what's there because it's going to become your responsibility and what's there might be wrong.)
  
  
• Do you know which circuits can be ring finals and which cannot, and what the advantages and disadvantages of each are? (No, you can't just copy what's there because it's going to become your responsibility and what's there might be wrong.)
  
  
• How do you calculate maximum demand and how can diversity be used?
  
  
• Can you correctly identify all components and connections of a circuit by method of testing or otherwise? In doing so can you identify or recognise anything wrong or dangerous with the circuit? You cannot assume that what's currently installed is OK, and you need to check it before starting work.
  
  
• Do you understand how the way in which cables are installed affects how much current they can carry? (No, you can't just copy what's there because it's going to become your responsibility and what's there might be wrong.)
  
  
• Where cables need to be joined, how should this be done / not be done and in what circumstances are different methods acceptable?
  
  
• Can you identify extraneous conductive parts, and do you know the requirements for main and supplementary bonding of them?
  
  
• Which circuits should be RCD protected?
  
  
• How do you propose to isolate your supply so that you can connect up your new CU?
  
  
• Do you know what tests you would carry out on the installation - what sequence you'd do them in and at what point you would energise the installation, and for each test do you know what is being measured, why it is important, how you would carry out the test, and with what equipment, and what sort of results you would expect to get if everything was OK?
  
  
• When you apply for Building Regulations approval what do you plan to say will be the way you'll comply with P1?
  

 

[MrTinker]

i thought this site was ment to give helpfull advice.

im very dissapointed in this site

it was just a bloody question calm down everyone just

Waza that is good advice! a bit harsh maybe from your point of view, but very much to the point, these guys are only trying to protect your bottom! changing a CU is in no way a diy job, and a little bit of knowledge and having a go could prove fatal, literally

 

[mbga9pgf]

i thought this site was ment to give helpfull advice.

im very dissapointed in this site

it was just a bloody question calm down everyone just

Waza that is good advice! a bit harsh maybe from your point of view, but very much to the point, these guys are only trying to protect your bottom! changing a CU is in no way a diy job, and a little bit of knowledge and having a go could prove fatal, literally

It can be, (with reverence to Part P), but I am only approaching being "comfortable" doing it after 6 months reading up on regs, on-site handbook, reading on here, elsewhere, practicing with a MFT on other Consumer units, and I will only attempt it after a few practice goes with a mock up board on a piece of Ply, once I am satisfied I have a tidy CU.

Oh, I also have an engineering degree.

So yeah, not your run of the mill DIY job I would agree and certainly not one to bodge.

 

[1john]

Fitting a board isn't rocket science, and surely doesnt need practicing, what is a little more scientific is testing, assessment of currend circuits and selection of protective devices required to protect them, being ratings for protection of over current or earth fault leakage. To assume that the correct devices are in place at the moment and to blindly copy them would be crazy. Also to go and whack a (hate this term) "17th edition board" with two 30mA RCD's controlling a complete property that previously had none or perhaps a 100mA or 500mA up front without doing and prior testing is crazy. There must be a fair few screwfix shoppers that have had to reinstall an old wylex board as a last resort because they cant get the RCD to set. Then there is earthing and bonding........... be careful what books you read on that subject too!