Replacing Consumer unit, What tests are required

[easysushi]

Guys,

I am going to be replacing a consumer unit as part of my NICEIC eval. Please can you answer the following for me.

What steps or tests are required before CU is changed ?

Do all circuits need to be re-tested R1+R2 ?
Do all circuits need to be re-tested for Insulation resistance ?

Any advice would be very much appreciated


Cheers


Ty

 

[Deleted member 9648]

I dont R1R2 if it is only a CU change but do Zs all final circuits. As you are likely to be changing the type of protective device it will be neccessary to verify that the new protective devices will meet the required disconnection time. I also IR test the installation as a whole, only if the reading is low will I test circuits individually.....RCD test on completion and of course verify bonding etc.

 

[nickblake]

I have to say i do R1 R2 tests and ring continuity tests , IR tests then Zs , Thewn RCD tests , install bonding to services and change the bathroom lights if they are incorrect for zones , then check for any damaged sockets and switches and replace if damaged , at the end of the day its my name on the cert / notify

 

[Graeme Harrold]

I also make sure both lighting circuits (if there are two) are independant i.e. no shared neutrals......

 

[nickblake]

I also make sure both lighting circuits (if there are two) are independant i.e. no shared neutrals......

Oh yes agreed with that one, pain in the but when that happens

 

[ezzzekiel]

tend to carry out ring final tests and ir testing only and check for borrowed neut on lighting, my reason being i find most other probs are easier to rectify

 

[Deleted member 9648]

I have to say i do R1 R2 tests and ring continuity tests , IR tests then Zs , Thewn RCD tests , install bonding to services and change the bathroom lights if they are incorrect for zones , then check for any damaged sockets and switches and replace if damaged , at the end of the day its my name on the cert / notify

Yes,I do ring continuity tests...end to end at least....forgot to put that in my above post.
I'ts amazing how many 'rings' on a 30a fuse in the old DB turn out to be non rings when you test them. Best to find out before you stick them on a 32a mcb in the new DB.

 

[nickblake]

I must admit i made that mistake years ago looked at a board counted circuits and fuse sizes then got a new board there wasnt a ring had to go out and get a bigger board and loads of16 amp mcb's , i have done the Zs tests and calculated the R1 R2 for the cert but it didnt feel right doing it , lol i know it sounds daft but i always learnt do the tests as the book then you cant go wrong

 

[topquark]

Basic premise should always be test everything both before (and fix any issues) and after the cu change. Otherwise how would you know whether you've introduced the problem or not?

Edit: If you take that a stage further and were working for a client. You change the cu and when testing find a problem that takes you two hours to fix how could you justify to the client the cost of fixing the problem (unless built into the quote of course).

 

[easysushi]

Basic premise should always be test everything both before (and fix any issues) and after the cu change. Otherwise how would you know whether you've introduced the problem or not?

Edit: If you take that a stage further and were working for a client. You change the cu and when testing find a problem that takes you two hours to fix how could you justify to the client the cost of fixing the problem (unless built into the quote of course).

For what its worth, I agree with your thinking

Keep'em coming guys all this info is just what I'm looking for


Ty

 

[Deleted member 9648]

Basic premise should always be test everything both before (and fix any issues) and after the cu change. Otherwise how would you know whether you've introduced the problem or not?

Edit: If you take that a stage further and were working for a client. You change the cu and when testing find a problem that takes you two hours to fix how could you justify to the client the cost of fixing the problem (unless built into the quote of course).

This discussion has been had on here before.
Personally I dont think it is practical to test everything before a CU change as it's likely the before CU change visit will be to quote.
Are you going to spend a couple of hours or more doing R1R2's,ring tests etc on a job you might not even get??
More often than not the CU you are going to change will be a right mess and next to impossible to work out correct neutrals and disconnect rings etc.
OK....in an ideal world yes....but in the real world an IR test is quick and simple and will give an instant idea of whether there is going to be any faults to rectify,but our quote will state that any faults found during the CU change will be rectified at extra cost.

 

[ezzzekiel]

very valid point

 

[mogga]

do a PIR before cu change (sort ahy issues arising) change CU then do a full test R1R2 IR cpc continuity rings continuity Zs Ze rcds

 

[Deleted member 9648]

do a PIR before cu change (sort ahy issues arising) change CU then do a full test R1R2 IR cpc continuity rings continuity Zs Ze rcds

Thats ok if the client is happy to pay and is definately going to have the work carried out by yourself, but I'll be ****** if I'm going to do a full PIR fpr **** all and then some other ****** does the job.

 

[Golden_Boy]

Thats ok if the client is happy to pay and is definately going to have the work carried out by yourself, but I'll be ****** if I'm going to do a full PIR fpr **** all and then some other ****** does the job.

If the customer doesnt pay up then Dont give them the test results. Then they will have to have it done again and again untill they do pay for it...