Discuss High Ze, Whose. Responsibility. in the UK Electrical Forum area at ElectriciansForums.net

ChrisElectrical88

-
Mentor
Esteemed
Arms
Reaction score
1,650
Morning chaps,

A bit of background. Finished a job yesterday, it was a bathroom install for the council on a private job. So with these they are grant work for the disabled, existing installtion dated, we have to note this on the certificate and install new circuit off a small new board for our installation. Earthing and Bonding ok etc etc. My installation all Fine and conplies with the regs.

Before starting noted it was a TN-S system, phoned up told it was an 80A fuse etc etc.

Came to test the Ze, PFC, initial IRs at the end of the first fix. Open up the dated unsealed DNO head. Found a fused neutral, Ze reading of 6.63 Ohms. Phoned the DNO, within a hour someone had come and put a front end RCD on the whole installation then 2 Hours after that they were under next doors floor repairing the cable, new head fitted top job. New Ze of 0.24 Ohms.

Now, this house had had a hob fitted on a new circuit by a local NIC electrician 6 months ago, got hold of the certificate and he had got high Ze readings aswell. I asked the owner (90 year old lady) and she didnt know anything, however her daughter said the electrician told them there was a high reading they needed to sort, but gave them no contact details, info or anything. He left the house knowing the 3036 fuses in her main board (2 of which had 1.5 in them instead of fuse wire, which i replaced, when doing these grant jobs i alway make sure the existing fuse wires are atleast fused correctly) would not be under their maximum Zs readings(No RCD).

Which brings the question, i have always notified the DNO on behalf of the customer for anything not fit... Is it our responsibility or the owner of the house?

Cheers
 
I would do the same as you. Had a similar situation once and when I rang the WPD call centre they did not want to know , would not acknowledge that the TNS supply was anything to do with them and it was down to me to sort it out. Fortunately I had the phone number of the local office and was able to sort it through them.
 
thing is, when contacting DNO you should always ask for the "duty engineer". usually, the above is not polishing fingernails or covering zits with face cement.
 
I rarely do it, did it because i was putting in a 9kW shower, no existing shower in place. We also install a 2kW downflow heater in these due to an outdated spec. Wanted to know there was at least east a 80A fuse in place.

Just phone the DNO, they should have the information to hand.
 
thing is, when contacting DNO you should always ask for the "duty engineer". usually, the above is not polishing fingernails or covering zits with face cement.
To be fair to the competent ladies who answer for Northern powergrid, They have always understood my every phonecall without repeated explanation no matter what the issue.
Situations have included cast iron service head upgrades, high Ze reports, damaged equipment reports, new supply requests, and the time the joint failed under my garden path.
 
So you illegally broke the seals on the cut out to check the fuse was big enough for the load. And the size of the cable back to the sub station? If you are connecting additional load you are supposed to check the complete supply is sufficient, not just the fuse. There are still a lot of properties where the whole street us fed by a 16mm paper insulated cable. Used to be a standard question when we went to a blown main fuse which was a rewireable 15 amp "ok who was in the shower".
 
op said that fuse was unsealed. all very well to call DNO to come out and check, but who pays for my time waiting for them ? can't tell customer that they will be out in 5 hours, so i'll be charging £25/hour to sit there doing nowt.
 

Reply to High Ze, Whose. Responsibility. in the UK Electrical Forum area at ElectriciansForums.net

Similar Threads

On an EICR I found a 200 amp 3ph supply, TNS earthing (which looks original) and Ze of 19 ohms. No rods. No RCDs. L1 -> N was about 0.5 ohms...
Replies
11
Views
952
Hi all, Customer has an extension and this compromises existing meter position, DNO is extending incomer and putting meter box on a different...
Replies
3
Views
360
Hi All New to this forum, have read the posts on here from google but only recently signed up. I'm having some issues and some input would be...
Replies
13
Views
1K
A friend of the family recently lost her husband to the big C so I need to be careful. Every small thing is sending her into tears so when her...
Replies
16
Views
1K
I've asked a similar question before I think and we came to the conclusion that apart from new houses and HMO's etc there aren't any rules about...
Replies
3
Views
256

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock