No incoming earth

[learner123]

Hey guy's

I was asked to put up some lights in an old house that was clear the electrics had not been upgraded. (Wylex plug in mcb's)

I noticed there was no incoming earth.
Thinking it could be a TT system I looked outside to see if the electrics where supplied by overhead cables. This was not the case.

I explained I couldn't put the lights up due to there being no earth or RCD's.

I told them to call there supplier to have an earth put in before I could do it.

My question is:
What are the regulations for unearthed properties & was I right doing what I did.

Thanks in advance.

 

[Lectrician]

If there was no means of earthing or RCD on a TT, you are right to walk. Similarly for the main protective equipotential bonding too.

As for looking for overhead cables....whats the point?

TT installations do not have to be fed from overhead. They can just as commonly be fed from underground.

 

[learner123]

Thanks Lectrician,

I didn't know TT could also be supplied underground as well.
There was no incoming earth & the garden has been concreted which make's it hard to put in an earth spike, though I did suggest that as a second option.

 

[securespark]

You're right. You should either spike a TT supply & fit RCD protection (if none present) or ask the DNO to supply PME. The Ze should be max. 200 Ohms, but I always try & aim for no more than 50.

You should also check PEB's too. If the customer is having PME, you need to ensure PEB's are in place before the PME terminal is connected up to the install.

 

[learner123]

Thanks Securespark

I did look for peb's but there was nothing in place.

 

[securespark]

Are you going back when the earthing is sorted? If they are going for PME (assuming it's available in your area), they'll need to get the PEB's done too.

 

[learner123]

I'm going there tomo to help call there supplier to see if we can get an earth put in place as they have agreed to have a new CU fitted.

Though said cant afford to have PEB's done as well just yet.

 

[Spark123]

The second part of fundamental Requirement 131.8 which is for alterations and additions says:
".. the earthing and bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate."
If you do the work you cannot sign it off to BS7671:2008 if the earthing and bonding are not adequate.

 

[londonboy]

Personally i'd install main bonding conductors first, then wait until they can afford the cu upgrade.

 

[Lectrician]

No incoming earth, or missing RCD on a TT (or the only protection being a voltage operated ELCB on a TT) should not be left until "they can afford it".

Luckily, the NIC do a danger notification certificate. If you really cannot sort the DANGEROUS nature of having no earth or RCD on a TT because of cost issues, then atleast you can cover yourself with one of these. Make sure you get the customer to sign it.

 

[Click-Sure]

The concrete should not really git in your way of spiking a TT.

Its what 16mm SDS drill bits are made for

 

[ColJack]

considering that you'd have to cut out an 8 inch square to get the earth rod cover in?

you can't just have the top of a rod sticking through a slab you know...

 

[Lectrician]

No, but you can put a surface rod cover over the top - The type with the conduit entry

 

[Click-Sure]

Precisely the option I offer to TT customers. Do get the odd one or two in south staffs.

 

[holmslaw]

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