High Ze reading

[Strickers]

I have recently re-wired a property with T-N-S earthing to find out that the Ze was 13.41ohm. I checked all the supply have to the spilt concentric incomer that looked pretty new. All connection were ok so i rang norweb. The question is does the DNO have to supply an earth to the property? An electrician i know said that the can just make to sort it yourself with an earth spike.

Cheers Paul

P'S before i left i put a 30ma RCD between the tails and the consumer unit
.

 

[SirKit Breaker]

Last time i came across similar problem i called YEDL on behalf of the customer, they sent an engineer within the hour and PME'd it.

Cheers............Howard

 

[pevvers]

The question is does the DNO have to supply an earth to the property? An electrician i know said that the can just make to sort it yourself with an earth spike.

Yep, there is a possibility that they can say that, or they could PME or fix the fault in the cable. The question has to be though, do you feel lucky?

Another question would also be how comes you didn't check the Ze before rewiring the property though, I thought that the first thing to do would be to check whether there was an adequate earth in line with reg 131.8.

But at least you've left it safe which some people wouldn't have done....

 

[Baal]

The Supply company has no obligation to supply an earth however if an earth has been supplied, there is an obligation to maintain it.

I came upon a similar situation a few months back and the DNO were out within 2 hours and found the fault after a further 2 hours.

Ze 16.7 Ohms originally, 0.25 Ohms on completion!

 

[Strickers]

Problem sorted thanks guys, the came out this week and i got a phone call from customer and a ze reading of 0.17 ohm.

 

[palmerelectrcal]

Hi I have the same problem... on an overhead supply...T-n-c-s Ze reading of 3.5ohms?.. giving me a PFC of 62A! a good distance from the sub.stn.
will the DNO be able to do anything with this?.

 

[Engineer54]

Hi I have the same problem... on an overhead supply...T-n-c-s Ze reading of 3.5ohms?.. giving me a PFC of 62A! a good distance from the sub.stn.
will the DNO be able to do anything with this?.

If the DNO has provided you with a PME connection, they are duty bound to maintain that earth connection. And 3.5 ohms on a PME system means there is something very wrong, probably a connection problem on the overhead supply.

 

[somersetsparks]

They will likely be out very quickly for a PME fault as it could be an immediate danger. Although pme faults are actually very rare.
With our lot we are still duty bound to maintain an earth were provided. This means if we can't repair we will supply 100ma time delay and plastic enclosure which is then also a handy isolator!

 

[palmerelectrcal]

If the DNO has provided you with a PME connection, they are duty bound to maintain that earth connection. And 3.5 ohms on a PME system means there is something very wrong, probably a connection problem on the overhead supply.

Ok many thanks. All ccts are RCD protected.And RCds tested for trip times.The figure rduces when i reconnect the bonding to i/c services.However its way over the required resistance.