UK High Ze TNS - what to expect from DNO?

[samtheman]

Thanks UNG! I hadn't spotted that.

The nice chap from SSE knocked on the door about 10 last night. He said he was able to get a reading of 0.7 ohms (just less than 0.8) but that it would probably be higher when everything was on. He said it probably still wanted doing.

He said he'd log it and if it remains "urgent" in the system they'll probably do it in days, otherwise weeks. I asked if they were likely to replace that head and if access was a problem. He reckoned they wouldn't replace the head, rather they'd dig up my drive to find the supply cable and attach something to it? Or I could pay my own electrician to fit ground rods.

Overall I sort of got the impression this was worth fixing but not getting too worried about.

 

[snowhead]

Is the wall with the cut out and gas meter on an outside wall with access outside?

I suspect if SSE decide to replace the head they'll want to dig up outside and joint the cable and then fit the new head in an external box, or if no space come through to inside with a new cable and fit the new cutout away from the gas meter.

 

[UNG]

I suspect if SSE decide to replace the head they'll want to dig up outside and joint the cable and then fit the new head in an external box, or if no space come through to inside with a new cable and fit the new cutout away from the gas meter.

The last time a DNO engineer suggested that they would dig up outside and put a new cable into the building I was working on I suggested he re-think that one, outside this building was the graveyard

 

[mainline]

The last time a DNO engineer suggested that they would dig up outside and put a new cable into the building I was working on I suggested he re-think that one, outside this building was the graveyard

Good suggestion to the DNO, as the supply outside was probably dead

 

[mainline]

Though nearly all the circuits are at least on RCBOs by the looks of it. what's the circuit closest to the Main isolator?

Are you on about the SPD mcb ?

 

[Chivers]

That makes sense now mainline!

 

[MDJ]

Clueless householder here!

My wife told me John Lewis refused to plug in our new oven this morning due to "high readings on sockets". It looks on their paperwork like the "Pre Earth Loop Impedance Test" failed with 2.02 Ohms.

I thought that was strange as we had a new consumer unit fitted and tested after buying the house, so I dug out the installation certificate which apparently says under part 5: "Supply company should be contacted to correct the very High Ze Reading of 1.57 Ohms without delay". Who knew? It says it's a TNS supply.

So not exactly without delay I decided to call 105 (SSEN) and apparently they'll send someone out. What should I expect from them?

Pretty sure I can figure out plugging in an oven myself but if this is dangerous I'd like to get it sorted.

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this is very old and I would have it ripped out and replaced, the Provider sse will probably say it needs stripping out and get things moving for you hopefully. Been a while since I saw anything this age, around here most places I have been it are in better nick, that was once though a great job installed by a decent guy and over the years aged and somehow the main earth has ended up like a pigs ear.

 

[samtheman]

Is the wall with the cut out and gas meter on an outside wall with access outside?

I suspect if SSE decide to replace the head they'll want to dig up outside and joint the cable and then fit the new head in an external box, or if no space come through to inside with a new cable and fit the new cutout away from the gas meter.

Good thinking - the other side of that is my garage and also where the gas comes in so probably quite a tidy solution if it comes to it!