Ze by enquiry or measurement - that is the question

[sparkybird]

Hi all

Wanted to pick your brains about something.

I alway measure Ze at an installation, but I understand you can also obtain it my phoning the REC and quoting the address of the property. Do they get this figure by measuring it themselves somehow, or do they just look it up somewhere?

I ask because recently on a copule of jobs the measured Ze has been outside that permitted and I've had to get REC to come and upgrade the earth. If I had phoned up about these properties, would they have said "Oh yea, you've got 5 Ohms there, love!"??

SB

 

[ban-all-sheds]

AFAIK they'll just quote the maximum allowable - 0.8 ohms for TN-S and 0.35 ohms for TN-C-S...

 

[dingbat]

Correct. They will simply quote the nominal value. And very likely the person who you talk to will not know what it means anyway.

I telephoned a REC today to report a high EFLI value. After three transfers I was finally put through to the engineering section where I was asked to spell 'impedance'.

 

[ban-all-sheds]

'i' for idiot
'm' for moron
'p' for pillock
'e' for educationally subnormal
'd' for dunce
'a' for a***hole
'n' for nitwit
'c' for cretin
'e' for electrocution if you don't get your act together....

 

[sparkybird]

Sadly, this is what I thought might be the case

So really, if you only find out about Ze by enquiry, the property (and people) could still be unsafe even after a rewire!

Madness!! I guess it all brings home to me how important it is to test, test, test - without it you'd never know!

SB