snipped cpc`s

[diditrain]

I have been asked to do a consumer unit change and have therefore done a bit of pre-work inspection and testing.
I have found a few minor issues which are easily rectified, however on one of the lighting circuits i have found that the cpc`s have been snipped right up to where the sheath has been stripped on the switch drops.
I am able to measure my zs at each lighting point but am unable to do it at the switch positons as the cpc is cut out.

Customer does not want the disruption of rewiring the switch drops so i feel that i will have to follow the protocol when the lighting circuits have no cpc present. Does this sound reasonable? Would appreciate others views on this issue.

 

[cjp1]

As long as there was no metal switch plates should be ok may be worth just making a note on the cert to cover yourself incase when you finish they follow you round and replace the plasic switches with metal ones.

 

[GaryM]

Agreed, make a note as it doesn't comply with BS7671:2008.

 

[malcolmsanford]

As you know regulation 412.2.3.2 does say that a CPC should be present at each point of an installation even if you use class II fittings.

But I think by changing the old CU, and assuming that CU does not have RCD protection, then by fitting RCD protection you are making the installation safer.

Now you will get get arguments that customer not wanting disruption of his house is not a way round the regs, and the other side of the argument will be you are leaving the installation safer.

For me I would be doing a risk assessment, can you perhaps get a 1mm G/Y single down to the switch via the tubing of the switch, have a try, if it is impossible then I would be still changing the CU, put a label at the CU saying about the CPC situation and finally on your EIC in the part about "comments on existing installation" and the "departures from BS 7671-2008" make an ote, with the relevant reg departure

Also this might be of use as a guide in the future

http://www.the50plus.co.uk/tech_support/best_practise_guides/BPG1_08.pdf

 

[GaryM]

As you know regulation 412.2.3.2 does say that a CPC should be present at each point of an installation even if you use class II fittings.

And 411.3.1.1

 

[malcolmsanford]

Gary a class II face plate will not be an exposed conductive part, perhaps the screws maybe if metal, but you can get screw caps and even nylon screws if you wished.

 

[GaryM]

Im not sure the last paragraph which relates to CPC's being run to and terminated at each point in wiring and at each accessory relates directly to exposed-conductive-parts nor insulation classes. Is it not more of a general requirement under the heading of protective earthing?

 

[malcolmsanford]

I have to admit Gary that the last paragraph can be interpreted to not just include exposed conductive parts but I always felt that as the other parts of the protective earthing section mention these exposed conductive parts and that the last part also includes the term then that is what it is referring to.

I have no problem if someone also wanted to include this reason on an EIC for a circuit without a CPC, but as 412.2.3.2 deals with the circuit as a whole I would use that one

 

[Inteificio]

Correct me if wrong, but any part of the circuit you work on has to be brought up to code?

To me that means if you are swapping a db, you pretty much have to ensure that the whole installation is compliant.

 

[GaryM]

Have a read of the ESC's Best Practice Guide when replacing a consumer unit where a lighting circuit has no CPC:

Best practice guides : Electrical Safety Council

 

[Octopus]

Correct me if wrong, but any part of the circuit you work on has to be brought up to code?

To me that means if you are swapping a db, you pretty much have to ensure that the whole installation is compliant.

everything brought up to code no. Equipotential bonding yes.

Just imagine all the work if every house you touched had to be brought up to the 17th?? - its wouldn't do you, or the business any good what so ever.

 

[needasparks]

Had this many times over the years and many were cut at the light end also so best to check, normally you can pull enough slack down the tube to get a crimp on and extend to the earth terminal. In 25yrs one's never beaten me yet. Or you could wimp out and put it on the cert.

 

[diditrain]

I have already tried to pull some slack down, that was my first thought. This is a no go as there is no tube, cable embedded in plaster.

 

[needasparks]

I have already tried to pull some slack down, that was my first thought. This is a no go as there is no tube, cable embedded in plaster.

Plan B then

 

[platty1005]

Go to this website and download the Electrical safety council guidance on replacing a CU with lighting circuits that have no CPC
PS: lots of other useful guidance also
Best practice guides : Electrical Safety Council