Changing a CU

[Delboybully]

I had a bit of a nightmare on saturday. Job was to change a CU.

Problems found

1. No earths on both lighting circuits. There was an earth present but DIY Dave has been in an didnt connect many of the earths up, left some hanging loose. So I told the guy that we need to remove all metal fittings and replace with plastic. There was also a N-E fault somewhere on both lighting circuits. He is fine with me coming back to sort out the lights, there are about 40 ELV downlights too as he wants his metal fittings and switches back.

2. The immersion is on the same circuit as the upstairs radial. Now i know that this should be on its own circuit but i cant see it as dangerous, it could just end up in annoying tripping of the MCB. Does this immersion need to be put on its own circuit or can it be left and just mentioned on the cert

3. The boiler is plugged into a socket that is on the lighting circuit. Again, this is not the done thing, but i dont see it as dangerous. The worst that could happen is that something could be plugged in that will cause the breaker to trip. Again, does this need sorting or can i just label the socket 'boiler only' and mention on the cert

4. One of the sockets radials had a dead short between L and N. We physically searched everywhere we could to find a load with no joy. Does this further investigation or can i just put n/v (not verified) on the cert. Everything works fine

5. The hot tub was so close to the isolator that i couldnt get it off to test. Was going to put it as something i couldnt test but as i am going back, he is going to empty it so i can test the cable for R1+R2.

I also found the kitchen circuit had a LN insulation resistance of 1.09M. He says he is going to have a new kitchen and he will get the kitchen fitters to sort that when they fit the kitchen (i dont believe this, i reckon he and his dad are going to fix or rewire the kitchen)

The guy has recently moved into the house as i think is planning on doing a lot of DIY electrics (like rewiring his garage) so i really need to cover myself.

He wants a certificate for the job but doesnt want to pay for anything that doesnt strictly need doing except for the lights as his wife like the metal lights and switches.

To recap.
Does the immersion need to put on its own circuit
Does the boiler socket on the lights need sorting
Does the radial with the load/short need finding or can i put N/V on the cert with an explanation

 

[telectrix]

your name going on the cert. get the guy to agree to pay to have these problems properly fixed or walk.

 

[PC Electrics]

So, you inspected and tested the installation prior to changing the CU. You found the above problems and you want to know what must be done to remedy them before you actually change the CU?

Correct?

 

[Octopus]

What did your quote/estimate say about who would pay for any "faults" found?

 

[cogsey133]

If you tested the installation prior to changing the cu (as is required) then the initial inspection would have failed anyway and the cu would not have been changed. If this is the case then the client needs to action your findings of the initial inspection.

 

[Delboybully]

I swapped the metal lights fittings for plastic ones and then changed the CU. My reasoning for this is that the system is safer now than before- i can guess from some of the above replies that i am going to get bashed for this.

The guy has said that if it has to be fixed then ok fix it but he has asked what actually needs to be done and what can be left, thus my questions

So given that the CU has been changed and going on from here does the immersion need to be moved to its own dedicated circuit, can the boiler be left on the socket on the lights and can i put n/v on the cert for the circuit with the hidden load.

Please go easy on me!

 

[needasparks]

Just a thought. What are you going to do if the client refuses to pay for the corrective works ?
Bearing in mind you already changed the board, will you cert the work you have done?

 

[cogsey133]

The point pc electrics and i are making is this: if you carried out an initial inspection before hand as is required the your questions would be academic as the list of issues you specify would need to be resolved before the cu is changed. Moving on from this i have always had the heating system on its own breaker as it is not advisable to have circuits doubled up in this manner; isolation needs for example cannot be done as you end up switching everything off for safe working. This aside there are also loading issues with this arrangement with the immersion being a heavy load. The hidden load does need further investigation as you say there is a short on it but everything works fine and i cannot see how this can be

 

[PC Electrics]

I swapped the metal lights fittings for plastic ones and then changed the CU. My reasoning for this is that the system is safer now than before- i can guess from some of the above replies that i am going to get bashed for this.
err, no. we want to help, but to do so we need to know the current situation

The guy has said that if it has to be fixed then ok fix it but he has asked what actually needs to be done and what can be left, thus my questions
of course he has! you've changed the CU already (which you shouldn't really have done), so he has got you by the short and curlies and he probably knows it! He could just pay you off at this stage and do no more!

So given that the CU has been changed and going on from here does the immersion need to be moved to its own dedicated circuit, can the boiler be left on the socket on the lights and can i put n/v on the cert for the circuit with the hidden load.

Please go easy on me!

The proceedure should be:
1. i&t installation looking for test results to use on cert and any faults / diy bodges / earthing & bonding requirements etc etc which might need remedial action prior to CU change
2. make remedials if required
3. change CU

Earthing and bonding must be up to scratch (though bonding may be left at 6mm if it is in good condition)
Other faults which which would generate a 1 or a 2 on a PIR should be repaired prior to change of CU. If client doesn't agree, refuse change.
Other faults which would generate a 4 on a PIR or which are not actually unsafe may be left but should be noted on the cert. You should however bring any 'contentious' issues to the clients attention and seek permission to repair.

Unfortunately you have shot yourself in the foot by changing the CU before identifying deficiencies. You now have no leverage with the client. Especially as you have identified the client as a leccy DIYer. He probably does want the CU changing properly with a cert so he can then DIY and pretend you did it.

The only leverage you have now is to withold the cert. Note that your scheme is unlikely to support that action.

I would strongly recommend that you download and read and understand the relevent ESC Best Practice documents before your next CU change. There's about 3 docs relevant here (changing a CU, changing a cu without cpc to lights and eicr guidance)

 

[cogsey133]

PC electrics make the case better than me and i agree with his list however just a point to note once the cu has been changed it should be retested. Apologies to pc electrics dont mean to teach old dog new tricks as your list is comprehensive.

 

[Delboybully]

Test first, then change CU if good, that makes sense.

I visually checked the bonding (10mm) when i quoted and also tested before CU change.

I disconnected the immersion when i IR tested the circuit with the immersion on it and still go 0M, so that needs to be further investigation

The guy just wants to know what needs to be done, he is ok with fixing what needs doing.

I will give him the news tomorrow

 

[cogsey133]

you say you tested before the cu change please do not miss the point here in that initial test would have failed and as such a failure test certificate should have been provided. Once the defects have been rectified the cu can be changed and then tested. this would generate a pass certificate for the client. The testing therefore should have been done Twice.

 

[Guitarist]

You say you disconnected the immersion, but is there a timeclock still in circuit?
Is the upstairs definitely a radial and not a RFC?

 

[ringer]

... a failure test certificate should have been provided... a pass certificate for the client...

What type of certs would they be then?

 

[PC Electrics]

I had a bit of a nightmare on saturday. Job was to change a CU.

Problems found

1. No earths on both lighting circuits. There was an earth present but DIY Dave has been in an didnt connect many of the earths up, left some hanging loose. So I told the guy that we need to remove all metal fittings and replace with plastic. There was also a N-E fault somewhere on both lighting circuits. He is fine with me coming back to sort out the lights, there are about 40 ELV downlights too as he wants his metal fittings and switches back.
not sure I understand how you can have a N-E fault when there isn't an earth, but I'll let that one go. It clearly needs to be fixed or your RCD won't hold.
No need to replace all metal fitings. Follow the ESC Best Practice proceedure which includes a risk assessment based on testing the IR of the fittings. And of course he wants the old fittings back! he's going to refit them!

2. The immersion is on the same circuit as the upstairs radial. Now i know that this should be on its own circuit but i cant see it as dangerous, it could just end up in annoying tripping of the MCB. Does this immersion need to be put on its own circuit or can it be left and just mentioned on the cert
what else is on this radial? what kind of loading? and what would be the ocpd? if you've set the ocpd correctly to protect the circuit cables then if the immersion is used at the same time as any other significant loading then the ocpd will open to protect the circuit. so not unsafe. not ideal, but not unsafe.
Also consider if the house has gfch which would be the normal source of dhw. if yes (ie has gfch) then leave it as the immersion would only be for backup, but note this on cert and advise customer to be careful of loading if needs to use immersion.

3. The boiler is plugged into a socket that is on the lighting circuit. Again, this is not the done thing, but i dont see it as dangerous. The worst that could happen is that something could be plugged in that will cause the breaker to trip. Again, does this need sorting or can i just label the socket 'boiler only' and mention on the cert
exactly. nothing wrong with a boiler on a plug per se. Not usual, but not 'wrong'. It's unlikely the socket would be used for anything else 'cos to do so would mean unplugging the ch, thus no heat or dhw! Label the socket, make sure the plug has a 3A fuse and note on cert. Or if it's a single socket, change it for an FCU. The actual load a gfch system presents is about 0.5A, most of which is the pump.

4. One of the sockets radials had a dead short between L and N. We physically searched everywhere we could to find a load with no joy. Does this further investigation or can i just put n/v (not verified) on the cert. Everything works fine
how can this work fine with a 'dead short'? if there is a dead short the ocpd will open! No, you can't put nv - you're supposed to be i&t'ing to find just this sort of fault and put it right!
Physical searching alone is unlikely to find the fault. Get busy with your tester and break the circuit down.

5. The hot tub was so close to the isolator that i couldnt get it off to test. Was going to put it as something i couldnt test but as i am going back, he is going to empty it so i can test the cable for R1+R2.

I also found the kitchen circuit had a LN insulation resistance of 1.09M. He says he is going to have a new kitchen and he will get the kitchen fitters to sort that when they fit the kitchen (i dont believe this, i reckon he and his dad are going to fix or rewire the kitchen)

The guy has recently moved into the house as i think is planning on doing a lot of DIY electrics (like rewiring his garage) so i really need to cover myself.

He wants a certificate for the job but doesnt want to pay for anything that doesnt strictly need doing except for the lights as his wife like the metal lights and switches.

To recap.
Does the immersion need to put on its own circuit
Does the boiler socket on the lights need sorting
Does the radial with the load/short need finding or can i put N/V on the cert with an explanation

i'll come back with more in a bit