How far do you go on a CU change?

[Snapester]

Doing a job today, filled with many faults, cutout changed last week but no earth reinstated!! Had to clamp on to cable sheathing getting good tns reading 0.40!!
Changed board but had fault on ring final rectified then found more ended up isolating the garage as was a dead short in there which was impossible
To access dude to loads of junk in there! So got ring working and safe but with no garage power!
Question is how far do you go on a cu change when faults are present?

 

[Doomed]

I test for faults before I change to CU normally.

However, when quoting did you warn the client that there may be extra costs if problems are found?

The end result is an installation that has been tested and certified by you, so you must do what needs to be done to give a satisfactory certificate.

 

[somersetsparks]

Doing a job today, filled with many faults, cutout changed last week but no earth reinstated!! Had to clamp on to cable sheathing getting good tns reading 0.40!!
Changed board but had fault on ring final rectified then found more ended up isolating the garage as was a dead short in there which was impossible
To access dude to loads of junk in there! So got ring working and safe but with no garage power!
Question is how far do you go on a cu change when faults are present?

I would get the dno to re-instate the earthing, BS951 clamps should not be used on lead cable sheath!

 

[Guest55]

You go as far as the customer pays.
Global IR test between L+N & E before changing the CU will give you all the warning you need that the rcd's arent gonna hold.

 

[Snapester]

To be fair it was a favour for a guy I knew his Wyler board had burnt out!! So I went round to change it and when I tested the one circuit I found the fault and it was sorted an hour later it tripped and fault was back!!! Grrrr!! As for the earth clamp is better than no earth! So..... Yeah

 

[somersetsparks]

To be fair it was a favour for a guy I knew his Wyler board had burnt out!! So I went round to change it and when I tested the one circuit I found the fault and it was sorted an hour later it tripped and fault was back!!! Grrrr!! As for the earth clamp is better than no earth! So..... Yeah

Indeed it is better then no earth, but come back in ten years and it is likely the clamp will be very loose as it has squashed the sheath! Quite a common find on an I&T, it is the dno's responsibility so you can just leave the clamp for now and report it to them!

 

[Guest55]

Didnt the fact his old CU burnt out hint that it wasnt going to be an easy job lol.
The clue is in the burnt bit ;-)
As for the earth clamp , meh , you did what you had to do so i wouldnt lose any sleep over it.

 

[Octopus]

Just make sure your estimate includes a statement which covers the situation(s) where faults are found, and thus additional costs are to be expected.

 

[oldtimer]

Yep global LN to E IR test then some random Zs plus a Ze and at no point give the customer the readings ie if he wants another quote I aint doing the work for the next guy. Then if you get the job first thing to do is check the ring as for the earth clamp well yep

 

[Snapester]

Ha yeah and no, I see Wyler boards burnt out a lot, the connections just become no good. But hey you win some you lose some!
I know the NICEIC and BS7671 don't agree with earth clamps on sheathing but when there is no earth provided and smashing a rod through the customers paved drive isn't acceptable, then I will go with a clamp! It seems strange that the DNO provide earthing via a clamp method but when we do it's frowned upon!! Go figure!

 

[ExArmy]

well generally you can't just leave it when you change the board and the RCD's are not holding, so you gotta goas far as it takes! sometimes if customers won't go for the estimate price of £300 if everything goes ok, then i say i'll have to do half a day testing first and then i'll give a fixed price for the board change.

 

[1shortcircuit]

Ha yeah and no, I see Wyler boards burnt out a lot, the connections just become no good. But hey you win some you lose some!
I know the NICEIC and BS7671 don't agree with earth clamps on sheathing but when there is no earth provided and smashing a rod through the customers paved drive isn't acceptable, then I will go with a clamp! It seems strange that the DNO provide earthing via a clamp method but when we do it's frowned upon!! Go figure!

IIRC I read a post on here (possibly E54?) explaining why these clamps should not be entertained on the sheath. I think it read that it CAN be dangerous if not carried out correctly?

 

[Snapester]

I can see it being dangerous if you don't take care just like not taking care with any type of electricity!

 

[Richard Burns]

I am surprised that Tony has not come forth with the constant force springs recommendation, these do not compress the sheath and avoid the potential for damage.

 

[cbw]

I quote to replace the fuse board!

If customers installation is faulty then that is another job.

See copy of standard quote,

I am happy to fix basic easy stuff along the way. ..
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