Prospective fault current

[sidekick]

I have recently had test readings as follows -
On a Fluke tester - loop test L/PE earth fault current 22.8 ohms but the loop test L/N was 0.14 ohms.
This points to poor main earth connection.

Should I report to DNO.

Have done in the past and after calling to test. They only test L/N and advise ok but direct Zs at light point fails with high reading.

Any help with this please.

 

[Darkwood]

Fault current is measured in Amps not ohms please clarify your result.

What is the nature of the supply TNS etc...

 

[sidekick]

sorry- TN-S and Ze 22.8 ohms with fault current of 10A as opposed to 0.14 ohms and 1.8KA on L/N

 

[SirKit Breaker]

Your results for a TNS are understandable, you have an adequate neutral path hence your PSCC is fine, but you are correct in your assumption that the main earthing is not well hence the crap PEFC and Ze.

Get the DNO out to fix it.

Cheers…………….Howard

 

[Darkwood]

http://www.electriciansforums.co.uk...cal-installations/9138-high-ze-value-tns.html

Read this 5yrs old but still has many valid points for you to consider and will save a drawn out thread..

 

[Engineer54]

http://www.electriciansforums.co.uk...cal-installations/9138-high-ze-value-tns.html

Read this 5yrs old but still has many valid points for you to consider and will save a drawn out thread..

Did you read that link before posting?? Right couple of charlies on there!! NOT exactly good advice to pass on when one, is just submitting to installing a TT system instead of insisting that the DNO provided a PME connection in accordance with the satutory duty to maintain a provided DNO earth!! lol!!

 

[Darkwood]

Browsed it quickly lol yep too quickly just re-read it ... ah well some of it was ok advice

 

[sidekick]

Browsed it quickly lol yep too quickly just re-read it ... ah well some of it was ok advice

Yep browsed quickly myself. Called DNO and they are calling today to do safety check.