Replace a Consumer Unit.

[aagohar]

I wanted to replace a Consumer unit, i bought a Consumer Unit with 100amp Fuse switch, TWO 80 m amp RCD attached to it.

I have been told that i have 63amp Supply coming into my House from the main supplier. Could any one tell me please that do i need to have 63amp main switch into my consumer unit as well.

Secondly, do i need to have 63 m amp RCDs or split load RCDs into my 2 bed property or 80m amp RCDs are good enough to cover my house. What is the difference of 63m amp or 80m amp RCDs.

Please help me. Thank you.

 

[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]

The best help you can be given is to find an electrician to change the consumer unit for you.

As you have asked

Could any one tell me please that do i need to have 63amp main switch into my consumer unit as well.

it is obvious that you do not have the basic essential knowledge to be able to start this work even it was permitted for you to do it.

The answer to you question is no ! the 100 amp main switch will safely switch 63amps. But as you do not know that you are not going to be able to make safe decisions for the many other factors involved.

For you own safety please do not attempt this work.

 

[1john]

Please dont attempt this work, it could be very dangerous to you and anyone else who lives or visits the property, you are quite likely to find that nothing will work as you will not have the correct test equipment or even know how to use it, installing a consumer unit is not a trivial task, it is a big undertaking to do it properly and to ensure everything is safe. electrics can work and be very dangerous at the same time.

 

[aagohar]

Hi,
Many thanks for the reply, i am not going to do it myself, i have hired a Part P Registered NAPIT electrician, who told me on the phone. i am paying him £450 which includes all circuit Testing , load size check, safety of my house and condition of the circuits.

I wanted to go back to the shop to return CU and replace it, then i thought i better take a suitable advise as well. For my knowledge i asked that if the Supply coming into my house is 63amp, i cant put a 100amp CU ? or , if my load is higher in that case i can put that 100amp CU up there?
Or i must buy a CU with 63amp Main switch?
I mean i can easily go back and return that and try to buy CU with 63amp main switch and RCD but i just wanted to make sure that i am doing the right thing or the Electrician is saying the right thing that i shall replace that.
Please reply.

• 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?
  

 

[ricicle]

The £450 is a reasonable price for the CU change (although I would be a little concerned about someone giving quotes over the phone !) Bear in mind there could be hidden costs if certain criteria are not met with regard to earthing and bonding. Let him get on with it. Take your parts back and save yourself the hassle.

 

[ban-all-sheds]

Hi,
Many thanks for the reply, i am not going to do it myself, i have hired a Part P Registered NAPIT electrician,

Well that was absolutely impossible to determine from this:

I wanted to replace a Consumer unit, i bought a Consumer Unit with 100amp Fuse switch, TWO 80 m amp RCD attached to it.

I have been told that i have 63amp Supply coming into my House from the main supplier. Could any one tell me please that do i need to have 63amp main switch into my consumer unit as well.

Secondly, do i need to have 63 m amp RCDs or split load RCDs into my 2 bed property or 80m amp RCDs are good enough to cover my house. What is the difference of 63m amp or 80m amp RCDs.

Please help me. Thank you.

Quite the opposite, in fact....

I mean i can easily go back and return that and try to buy CU with 63amp main switch and RCD but i just wanted to make sure that i am doing the right thing or the Electrician is saying the right thing that i shall replace that.
Please reply.

Take it back, and get your money back, not another CU.

Let your electrician get on and do his job, which includes supplying the parts he needs.

 

[AndyPRK]

I don't think there is anything wrong with the CU (unless it is metal and your have an earth rod).

You would be best to ring your electrican and tell him it is brand X, X way dual RCD. And ask if that is ok. Or should I return it.

 

[ricicle]

I don't think there is anything wrong with the CU (unless it is metal and your have an earth rod).

You would be best to ring your electrican and tell him it is brand X, X way dual RCD. And ask if that is ok. Or should I return it.

Although any half decent electrician would be foolish to fit a consumer unit supplied by a customer.....

 

[Click-Sure]

I know I wouldnt!

 

[holmslaw]

..

 

[ban-all-sheds]

You would be best to ring your electrican and tell him it is brand X, X way dual RCD. And ask if that is ok.

You're assuming that he's not on holiday.....