CPC/Earth feed to Light Switch Back Box

[westward10]

Not saying a word it is Sunday.

 

[BettyBoop44]

OK guys thank you for all your feedback the conclusion they have to have a cpc to each box/switch , there is only 3 walls to chase down other half will not be happy though it has to be done , would not of looked if it was not for the info my friend told me .

thanks again

BB

 

[BettyBoop44]

What size cpc and what routing did you take when installing he seperate cpc as there are regulations governing what should be done

Hi
I took a 2.5mm direct from the earth bonding box next to meter ! , I have to also mention that this problem is only on the lower floor switches upstairs are all fine .
ps: what reg is it that covers that ! .
BB

I assume these are flush to the wall boxes and plastic isn't ideal for this. Do the existing boxes have plastic lugs for the cover screws.

Yes.

 

[Pete999]

OK guys thank you for all your feedback the conclusion they have to have a cpc to each box/switch , there is only 3 walls to chase down other half will not be happy though it has to be done , would not of looked if it was not for the info my friend told me .

thanks again

BB

And each light point

 

[Des 56]

Hi
I took a 2.5mm direct from the earth bonding box next to meter ! , I have to also mention that this problem is only on the lower floor switches upstairs are all fine .
ps: what reg is it that covers that ! .
BB


543.1.1

 

[BettyBoop44]

And each light point

Read my #10 post in this thread ! .

 

[davesparks]

Hi
I really need a answer to my first post ie , can I fit a plastic back box in place of the metal one and then not need a cpc !

No, the regulations require that the cpc be present at every point in the circuit regardless of materials used.

 

[davesparks]

If the back box and light switch are both non metallic then no CPC is required.
.

This is incorrect, the regulations require that the cpc is present at every point on circuits where ADS is used.

 

[Pete999]

Hi
Thanks for your reply , I am talking about my house not my friends friends house ! , the feed to the lights were also just 2 core flat , I fit a cpc to them a long time ago direct from the cpc bonding terminal next to the meter ,but did not think about the light switches , the kitchen and lounge light switches have a cpc they where put in when some workwas done there prob about 5 year ago .

cheers

BB

What size cpc did you use and why take from a BONDING conductor connection, ?

 

[telectrix]

What size cpc did you use and why take from a BONDING conductor connection, ?

it's also an earthing terminal (MET). better would be to connect to the earth bar in the CU in the correct point for the circuit. and, if not mechanically protected, should be min. 4mm, but that's a minor point.

 

[BettyBoop44]

it's also an earthing terminal (MET). better would be to connect to the earth bar in the CU in the correct point for the circuit. and, if not mechanically protected, should be min. 4mm, but that's a minor point.

Hi
Thanks for your reply , what would be classed has "mechanically protected" under the floor boards ! , that is were I put the 2.5mm² cpc run , crikey I would not of liked to have tried to put 4mm² to my light fittings , the ceiling would of come down with the weight of the copper lol .
anyway thanks for your reply , great place to learn .
ps: by the way when did that reg come out 543.1.1 regarding the 4mm² , will feed it into my CU , has been recomemended , where I have it fed from now is the same point my CU is fed from ! .

BB

 

[westward10]

I have just found the same Reg 543.1 in my 1981 Fifteenth Edition but it has been around longer than that.

 

[Pete999]

Hi
Thanks for your reply , what would be classed has "mechanically protected" under the floor boards ! , that is were I put the 2.5mm² cpc run , crikey I would not of liked to have tried to put 4mm² to my light fittings , the ceiling would of come down with the weight of the copper lol .
anyway thanks for your reply , great place to learn .
ps: by the way when did that reg come out 543.1.1 regarding the 4mm² , will feed it into my CU , has been recomemended , where I have it fed from now is the same point my CU is fed from ! .

BB

2.5 protected i,e, in conduit or trunking, yes the MET is electrically connected to the earth bar in your CU but it is recommended that cpcs are connected in the CU

 

[BettyBoop44]

2.5 protected i,e, in conduit or trunking, yes the MET is electrically connected to the earth bar in your CU but it is recommended that cpcs are connected in the CU

Hi
Thanks again for your help , just one more and I will leave you alone , if I was to get a EICR for my house would they not pass it , if they had seen the 2.5mm2 cpc I put in the ceiling void to the lights ! .

 

[westward10]

Hi
Thanks again for your help , just one more and I will leave you alone , if I was to get a EICR for my house would they not pass it , if they had seen the 2.5mm2 cpc I put in the ceiling void to the lights ! .

Depends how clued up the person is doing the inspection.

 

[BettyBoop44]

2.5 protected i,e, in conduit or trunking, yes the MET is electrically connected to the earth bar in your CU but it is recommended that cpcs are connected in the CU

Hi
Thanks again for your help , just one more and I will leave you alone , if I was to get a

What size cpc and what routing did you take when installing he seperate cpc as there are regulations governing what should be done

Hi
From the MET straight up into the loft then through each floor joist to each light ! , going to put it into the CU earth bar instaed of the MET .

cheers

 

[Pete999]

http://www.electricalsafetyfirst.org.uk/mediafile/100404922/Best-Practice-Guide-4-Issue-4.pdf
Give it a C3 possibly C2 is about all I could recommend from a distance

 

[BettyBoop44]

I have just found the same Reg 543.1 in my 1981 Fifteenth Edition but it has been around longer than that.

Thanks for that , looks like I am going to have to change the 2.5mm2 to 4.0mm2 to the lights mam a mia , that was a job and a half putting in the 2.5mm2 from what I can remember , but you can't have enough supplimentry bonding in the house and I have a lot , water n gas pipes were I have been able to get to them , I hink there is more copper in the cpc's around the house than in Zambia ! .

cheers guys and thank you all for your comments and help .

BB

 

[Pete999]

Thanks for that , looks like I am going to have to change the 2.5mm2 to 4.0mm2 to the lights mam a mia , that was a job and a half putting in the 2.5mm2 from what I can remember , but you can't have enough supplimentry bonding in the house and I have a lot , water n gas pipes were I have been able to get to them , I hink there is more copper in the cpc's around the house than in Zambia ! .

cheers guys and thank you all for your comments and help .

BB

If you are going to access the routes to the lighting points why not run a new twin and cpc cable? sounds like you have been bunging supplementary bonding every where, has the pipework been tested to see if it actually requires bonding?

 

[telectrix]

i'd give the 2.5mm cpc a C3,