Pre Change Checks On A CU

[irishsailor]

Hi

Just a general query can someone tell me the pre-checks and test you should do prior to a CU change to avoid any major problens after new CU is fitted.

Cheers

Chris

 

[marksparky]

i wud do ze, zs, contiuity and most importantly insulation resistance i learnt that the hard way changed a cu for family member without prior testing and both ring circuits were shorting to earth nightmare to put right and i had to put right mysel as far as they were concerned it was fine b4 i touched it! no point explaining that was because there was no rcd protection

 

[simonspark]

i wud do ze, zs, contiuity and most importantly insulation resistance i learnt that the hard way changed a cu for family member without prior testing and both ring circuits were shorting to earth nightmare to put right and i had to put right mysel as far as they were concerned it was fine b4 i touched it! no point explaining that was because there was no rcd protection

I wouldt go that far. To do all the above would take rather a long time and if your just being asked to give an estimate, who pays for your time? However, I recommend that the customer has a PIR before any consumer unit is installed and if they go ahead with it then you know what youre up against. And offer a discount on the test if they then proceed with the works. The advantage for the customer here is that they can use your findings to give to other sparkys to quote for.
But the things that must be in place to change a board are all the main bonding. There is also a procedure according to the nic where the existing lights are not earthed and I cant remember it! But its common sense. Sort of!
Plus at the end of the works I issue a completion for the board and anything else I have done ( 10 years) and a satisfactory pir ( 5 years)

 

[Guest123]

Ring final continuity and a blanket IR.

Also a visual on some accessories, earthing and bonding etc. Depending on the results of the "snapshot" of the install, advise the customer accordingly.

 

[simonspark]

Lenny, thats all very well. But suppose youve done a ring final cont check on a wylex board and the terminal screw snaps off. Or you do it from a socket and the 3.5 lug loses its thread. Or its one of those squeeky threaded dry liner threads and you know whats gonna happen just as you get to the end of tightening it up. I still say do a PIR

 

[Guest123]

If they're willing to pay for a PIR then it's happy days.

As a minimum what I posted above is what I will do regardless, better than going in blind surely???

 

[simonspark]

But its the "what if" factor that springs to mind. Im sure weve all been there to either help a mate out or to do something that
will take 2 minutes. (no idea what happened to my spacing back there) Im not being a money grabbing old git, but I have found its the daftest little prob that turns into some sorta nightmare!

 

[Tester Steve]

Minimum for me:

Ze, bonding check, cpc's in lights and rings, IR test.

I would rather spend an hour doing the survey (usually get a cuppa as well!) and chatting to the person building up the relationship than doing nothing and finding faults later! Then the quote will be a good 'un and nothing to bite you later.

Agree simon that if they go for a pir, then all the better!

Steve.

 

[irishsailor]

Guys

Many thanks your help and suggestions are greatly appreciated

Chris

 

[m25maintenance]

Hi

Just a general query can someone tell me the pre-checks and test you should do prior to a CU change to avoid any major problens after new CU is fitted.

Cheers

Chris[/
i changed a cu last week without checking all was well, so then the rcd was tripping on the upper ring. i discovered after a few hours and floors up that a plumber drove a screw into the line of one leg of the ring and into the earth of the return leg. no worries the customer paid an extra day.

always agree with customers 1st that any faults found will cost more cash to correct. some people think its included in cu exchange price