Legal requirements for earthing.

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andson

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Do both sockets and lighting circuits require and earth, or is it just the lighting circuit, we live in old house that has no earth,

cheers andy

 
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Sockets yes, lighting should be present but not necessarily required. Older properties from the 70's were wired without an earth conductor, which was acceptable at the time. However things move on, and this is no longer acceptable practice, but if you are stuck with this there are several ways to proceed

1/ make sure no metal switch plates or light fittings are present on the circuit -everything must be class II insulated (ie plastic)

2/ re-wire circuit in modern flat twin and earth cable or provide separate earth lines to lights etc.

3/ add RCD protection to circuit to improve matters but still complying with item 1

There is an article on the NICEIC website covering the subject under guidelines for changing Consumer Units.

However given that your cables are now 40 odd years old, I would seriously consider re-wiring premises (maybe in stages) because the insulation is probably starting to deteriorate and there maybe other issues starting to affect the safety and integrity of your electrics. I would strongly advise getting an electrician to perform a Periodic Inspection Report, which will give you a fuller assessment of the situation.

 
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Binky, you young whippersnapper. You find generally houses wired after 73 do have a Cpc. An old house with no earth is going to have wiring considerably older than 40 years. 40 year old cable is perfectly acceptable and it would be most unusual for it to fail an insulation test. Pvc cable has been around since the early 60's and that's ok today.

 
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Binky, you young whippersnapper. You find generally houses wired after 73 do have a Cpc. An old house with no earth is going to have wiring considerably older than 40 years. 40 year old cable is perfectly acceptable and it would be most unusual for it to fail an insulation test. Pvc cable has been around since the early 60's and that's ok today.
If I'm a whippersnapper,that makes you a coffin dodger:^O:^O

40 year old cable can still be in good condition, but lack of maintenance of circuits / DIY / cowboys cause the biggest problems, plus sheath may have been damaged on installation, or by vermin. Depending on circumstances re-wire might be better option??? Hence also recommendation to PIR.

Take todays job, similar age to above scenario with no CPC on lighting. Have found 3 circuits linked to / through central heating system - 1 linked to immersion circuit (which is wired from upstairs sockets), 1 to the lights and 1 to new circuit supplying the boiler. So firkin annoyed I nearly phoned NIC inspector. Two of these connections being within last few years - I have the joy of sorting this out tomorrow as well as changing CU, investigating garage bodge, and trying to fathom, whether cooker cable is connected to anything. If the house wasn't concrete it would almost be easier to re-wire and that would offer better value for money than lots of firkin about.

 
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. Pvc cable has been around since the early 60's and that's ok today.
Apart from the undersize CPC on early metric cable of course - only an actual issue on 32A re-wireable fuses.

Out of interest old timer, do you know what is the ampage rating of old imperial cable that looks like 4mm but isn't?

 

robertarathoon

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Be careful cable of 40yrs or older could have some hidden defects, and doubt the installation would comply to the 17th edition BS7671:2008 why not reccomend your client for a rewire as outlined in the regulations any vable or accesories aged 25yrs+ must be replaced and brought up to modern regulations.

 
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I did not say that the customer may not be better off rewiring a house. You have to be careful how you word it nowadays, so as not to be thought of as a rip-off merchant. I normally word it something like , 'Due to today's regulations it would be more economical to rewire than to carry out alterations and additions'. That phrase gets used on almost every board change job, unlike some people i have heard that as soon as they see an old Wylex standard range C/U its tut tut, thats illegal.

 
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I agree slips we should be careful. Each job has got to be judged. I personally recommend rewireing unearthed lighting circuits no cabling will last forever. You wouldn't drive around in a 40 year old car everyday. My thoughts on the 17th edition wiring regs and the need for 30mA Rcd protection on most circuits is wrong. I shall not be changing my split load board to put Rcd protection on lights and cooker circuit in my house.

batty

 

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