Advice from an electrician, please

jdp1962

jdp1962

Grumpy Old Man
Joined
May 26, 2003
Messages
10,272
Reaction score
4,610
Points
113
Location
Northumberland
Good morning,

I'm hoping we have a sparkie on the form who can help me. I had some electrical work done last week; a modern RCD fuse board and some extra sockets etc. When it was finished, the guy explained that the earth readings he was getting were too high, and I needed to contact my supply company. Here's word for word what he wrote in an email to help me when I'm talking to the supplier.

"You currently have a TN-S earthing system (earth clamp connected to the lead core of your incoming electrical supply cable), unfortunately the earth reading that this produced was not within regulation, the reading was 2.49ohms.

Explain to the supply company that your electrician has suggested that you would benefit from a new meter being fitted. The current setup is quite old and you still have a 'wheel type' meter. Whilst they are carrying out this work, would they kindly supply you with a TNC-S earthing system. (Where the earth is taken from the neutral bar).

If they will not come and carry out the above work for you, then you will have no option but to hammer earthing rods in to the ground under the floorboards until a sufficient earth reading is obtained."

Before I do that, I was hoping for some pointers on what would be involved, how likely it is that the supply company will do what he's suggesting and also, what are the consequences are if I do nothing but leave it as it is.

Thanks

Jeff
 
@jdp1962 I work with a load of electrical engineers so will ask them and come back to you tomorrow and see what they say.
 
  • Like
Reactions: jdp1962
@jdp1962, Hi Jeff, spoke to my colleague at work and he agrees that the reading of 2.49ohms is very high and regs advise that it should be around the 0.35ohms mark. First port of call as suggested would be to get in touch with the supply company and let them know that you have had this work done and the reading is as such, therefore what can they do about it as its a potential fire risk....he suggested to go to them first and see what they come back with, said that the lead core has probably broke or got damaged which is causing the reading to be so high.

Hope that helps.
Nilz
 
  • Like
Reactions: Sandra, Ghost and jdp1962
Nilz said:
@jdp1962, Hi Jeff, spoke to my colleague at work and he agrees that the reading of 2.49ohms is very high and regs advise that it should be around the 0.35ohms mark. First port of call as suggested would be to get in touch with the supply company and let them know that you have had this work done and the reading is as such, therefore what can they do about it as its a potential fire risk....he suggested to go to them first and see what they come back with, said that the lead core has probably broke or got damaged which is causing the reading to be so high.

Hope that helps.
Nilz
Click to expand...
Thanks; I've got a call out with UK Power Networks. They didn;t make it here today, so it'll probably be Thursday now.
 
OK mate, well keep us posted and let us know how you get on.
 
Nilz said:
@jdp1962, Hi Jeff, spoke to my colleague at work and he agrees that the reading of 2.49ohms is very high and regs advise that it should be around the 0.35ohms mark. First port of call as suggested would be to get in touch with the supply company and let them know that you have had this work done and the reading is as such, therefore what can they do about it as its a potential fire risk....he suggested to go to them first and see what they come back with, said that the lead core has probably broke or got damaged which is causing the reading to be so high.

Hope that helps.
Nilz
Click to expand...

Thats incorrect, the max permissible value for a TNS system is 0.80 ohms, 0.35 is for a TNCS system(which he currently doesn't have)

2.49 ohms is high and would suggest a loose connection somewhere, your electrician has done the correct thing by informing you,
by any chance is your house terraced?

It was a very common setup years ago for suppliers to "piggy back" supplies to homes, so the supplies comes into the first house, out into the second, from second to third and so on...

The problem with this is that the earth was also piggy backed, so if your house number 10, in house number 6 the earth connection could be loose or came off, then all houses after that have poor readings

Could you attach a photo of your main fuse/cutout setup (below the meter)? i could be able to tell you
 
  • Like
Reactions: jdp1962 and Nilz
Thanks, @Vernam616 , I'm at work right now, so can't post a pic. It's a semi-detached house built in 1928. UK Power Networks visited yesterday, took one look at it and said it wasn't their problem because they don't "own" the type of earth I have. Something to do with Ofgen limiting the liability of the successor companies to the old regional electricity boards. Despite my repeated requests that he use layman's language, he kept using technical jargon that went over my head. To give you an idea, apparently, if I had a sweaty earth, I'd be covered.
Anyway, he suggested the best solution was to sink earth rods into the ground outside the house, and connect them through the wall to the supply. That would mean breaking through the concrete footpath at the side of the house, but I have been contemplating replacing the front drive and footpath, so it might be sensible to get it done then.

But he also said that because my brand new fuse box has RCDs built in, I don't really need to do anything. I think another conversation with my own electrician is due.
 
That advice he's given you is terrible, im pretty sure they have to provide a suitable earth.

Anyhow if you go for rods, lift a floorboard near the consumer unit and bang them in from there, saves messing up your drive and routing a cable through the house
 
  • Like
Reactions: jdp1962
Vernam616 said:
That advice he's given you is terrible, im pretty sure they have to provide a suitable earth.

Anyhow if you go for rods, lift a floorboard near the consumer unit and bang them in from there, saves messing up your drive and routing a cable through the house
Click to expand...
Thanks, mate. I kind of got the impression he was blowing me off. I'll speak to my own sparkie again, and if need be, pay him to perform acupuncture in the meter cupboard. :)
 
jdp1962 said:
Thanks, mate. I kind of got the impression he was blowing me off. I'll speak to my own sparkie again, and if need be, pay him to perform acupuncture in the meter cupboard. :)
Click to expand...

It is the responsibility of your electricity supplier to supply you with a suitable earth connection, asking you to start installing earth rods into the ground below your floorboards is a joke.
Get them back and hopefully you will get someone who is actually interested in their job, unacceptable response from original person.


Sent from my iPhone using Tapatalk
 
That's the problem, I'm being bounced back and forth between my energy supplier and UK Power Networks.
 
jdp1962 said:
That's the problem, I'm being bounced back and forth between my energy supplier and UK Power Networks.
Click to expand...

That is crap and probably what we expect, as was the comment you got from UK Power Networks wrt limiting liability from previous companies! I'm guessing that the "with that new consumer unit you don't need to do anything" is roughly correct but not good, ie nothing really bad should happen. How about applying to your energy supplier for a smart meter as there is meant to be funding available for that work? That might prompt the installer to pass out some better comments to take to the "no can do" people?

Edit:- I suppose that you know that as a nation we are moving to maybe initially a 2 wire system for domestic electrical installations, though a friend who has just converted a large workshop into a house does still have a separate earthing rod - so maybe he is on a single wire system(?) or that conversion was not looked on as being a new build?
 
  • Like
Reactions: quattrogrip
I've decided to take the line of least resistance and have my sparkie fit earth rods. It's not ideal but at least I'm dealing with someone I can trust.
 
  • Like
Reactions: Nilz and desertstorm
Not ideal, however as you say at least you are dealing with someone you know and the issue will hopefully be sorted too.
 
Depending on what the ground is like in your area, you may find he has to bang quite a few rods in

The record for me is 12 rods, coupled together one on top of the other. each rod is 1m long !

Still didn't get a fantastic reading, but it was permissible under regs

I would seriously push to get them to supply and earth.
 
Update; my sparky came back today, armed with five earthing rods, various clamps, and metres of green and white earthing cable. He'd called the certification body (is it IET?) who'd told him that a reading below 200 somethings was necessary for me to get a safety certificate. The starting reading was over 400. He sunk three rods, connected them to each other, and took a reading; 175. I asked him to put one more in for good luck. He did, and by the time he'd finished adding clamps and routing earth cables to the appropriate places, it was down to 36.

All done in under two hours, total cost £200. That's a much happier result, for me at least, than having UK Power Networks dig up my drive and footpath to run sweaty earths from the road to the fusebox.
 
  • Like
Reactions: Nilz
Aye, well, I've been at 400 plus for the last 23 years without ever knowing. I can live with 36. :)
 
  • Like
Reactions: Vernam616
jdp1962 said:
Aye, well, I've been at 400 plus for the last 23 years without ever knowing. I can live with 36. :)
Click to expand...
Rephrase that to "I've been lucky for the past 23 years", you never know when a fault may strike, thats the time you'll of relyed on it, happy to hear your sorted now though
 
  • Like
Reactions: jdp1962
Good result @jdp1962 , at least its sorted now and at a level thats more realistic than what it was at previously!!
 
You must log in or register to reply here.

Similar threads

S
Advice from Scotland please
Replies
8
Views
1K
gjcknocker
gjcknocker
J
Advice please
Replies
2
Views
525
Chrisrobbo102
C
Randomjim
Advice please
Replies
16
Views
822
SteveS
SteveS
D
Forum Advice Please!
Replies
2
Views
429
dtmullins95
D
A3_Turbo
Accident Advice Please
Replies
5
Views
945
Rev-head
Rev-head
Top
Back