Why did the Ra go from 180Ω to 14Ω?

[PEG]

This sounds like Ze not Ra??

Nope,we are talking Ra,in it's meaning of "...total resistance of the earth electrode and the protective conductor connecting it to exposed parts..."
The methods used to test this,were not a bone of contention,in the OP's post.

My assertion that work carried out by any DNO,can vary the test readings,whatever method of test is used,stands.

I'm prepared to accept potAto/potARto,tomAto/tomARto...lets call the whole thing off...it was only the word "impossible",that got me going....

 

[Bellendian]

Ah....I have to admit that I don't possess an electrode tester, and only use the efli test method on tt.
I had it in my head that if you did a bone-fide Ra test, then you were literally just testing the electrode to the test probes in isolation, i.e. the earthing conductor would not be connected to the electrode under test.
If the earthing conductor remains connected, then the effects of any DNO activity could still be seen?

 

[PEG]

It is the method of choice,usually,due to many reasons. Not having easy access to disconnect the earthing conductor...not being able to stick your spikes in at the correct spacings...time...patience...etc

As for any work the DNO could do,having an effect on the readings on an earthing electrode,tested in isolation...again,unlikely but certainly possible - as are a myriad of other entities,being the cause of varying any other result we seek in life.

I have prided myself,on the ability to discover faults,where others had either failed,or give up. One of the most useful assets,in these endeavours,is never discount any variable - however bizarre or unlikely

 

[Nigel]

Ah....I have to admit that I don't possess an electrode tester, and only use the efli test method on tt.
I had it in my head that if you did a bone-fide Ra test, then you were literally just testing the electrode to the test probes in isolation, i.e. the earthing conductor would not be connected to the electrode under test.
If the earthing conductor remains connected, then the effects of any DNO activity could still be seen?

Ra is a dead test. If you are carrying out the EFLI test, which is a live test, this is called Ze.

 

[telectrix]

OMG. I've agrred with essex. that's twice in under 10 years. this has to stop. knuckes rapped. .

 

[Harry_P]

It is the method of choice,usually,due to many reasons. Not having easy access to disconnect the earthing conductor...not being able to stick your spikes in at the correct spacings...time...patience...etc

As for any work the DNO could do,having an effect on the readings on an earthing electrode,tested in isolation...again,unlikely but certainly possible - as are a myriad of other entities,being the cause of varying any other result we seek in life.

I have prided myself,on the ability to discover faults,where others had either failed,or give up. One of the most useful assets,in these endeavours,is never discount any variable - however bizarre or unlikely

the other useful asset needed is a client willing to pay for your protracted fault finding endeavours (unless you do it for free)

 

[PEG]

the other useful asset needed is a client willing to pay for your protracted fault finding endeavours (unless you do it for free)

Alas,yes,this would be the driving factor,i suppose,with many jobbing sparkies...

I do not fit in to that category,so my reasons for getting involved and stuck-in,to a quandary,are different.

Customers who tell you half a story,give you rules,times,costs and a flatulent pet,to work round....are NOT my idea of fun

Those that have to face such obstacles,have my respect and sympathy

 

[richy3333]

It's Friday, I have popcorn and wine and am now awaiting Essex"s explanation as PEG rose to the challenge and gave his.

So Essex can we hear your theory for the argument on the flip side please?

 

[Midwest]

It's Friday, I have popcorn and wine and am now awaiting Essex"s explanation as PEG rose to the challenge and gave his.

So Essex can we hear your theory for the argument on the flip side please?

Some people watch Strictly or X Factor for their weekend excitement.

 

[richy3333]

Strictly's finished and my work pants can't take any more sequins!

 

[Midwest]

Some people watch Strictly or X Factor for their weekend excitement.

Come on @DPG, I bet you like all those leotards and tap shoes.

 

[DPG]

Maybe. Not saying.

 

[Dave OCD]

It is the method of choice,usually,due to many reasons. Not having easy access to disconnect the earthing conductor...not being able to stick your spikes in at the correct spacings...time...patience...etc

As for any work the DNO could do,having an effect on the readings on an earthing electrode,tested in isolation...again,unlikely but certainly possible - as are a myriad of other entities,being the cause of varying any other result we seek in life.

I have prided myself,on the ability to discover faults,where others had either failed,or give up. One of the most useful assets,in these endeavours,is never discount any variable - however bizarre or unlikely

Me too PEG , and today I was on such a fault finding mission. It involved measuring below and then lifting a 9"square of upstairs chipboard flooring- which still had the original old floorboards beneath. Fault 1 was a badly terminated live in a broken pendant base used as a JB in the void above the lounge light and fault 2 was a burned 1mm squashed behind a heating pipe, very satisfying to find,fix then test and get good results, I'm the 3rd Electrician called in to sort out this one [and the 1st invited via recommendation], knackered now though.

 

[Nigel]

It's Friday, I have popcorn and wine and am now awaiting Essex"s explanation as PEG rose to the challenge and gave his.

So Essex can we hear your theory for the argument on the flip side please?

Eh?

 

[johnduffell]

measuring below and then lifting a 9"square of upstairs chipboard flooring

That's impressive, how did you work out the location of the fault, was it something fancy like time domain reflection to find out the distance to the fault, or something less exotic like a mirror and steel tape?

 

[Dave OCD]

It was a combination of experience, optimism and desperation. And measuring carefully to lift the floor exactly above the living room light fitting.

 

[weevilward]

Yep ok, agree it wouldn't affect Ra if measured with electrode tester.
But it could change a Ze done with a loop tester, which I guess is what you're getting at?

So if there are dodgy DNO rods out there leading to a very high ELFI - Isn’t a Ze test more meaningful (and important) than a dead Ra test? After all, the touch voltage and the successful operation of the RCD depends on the EFLI being low enough. You could have the best customer earth rod in the world but if the nearby DNO rod is pants then the EFLI will be very high.

 

[PEG]

It was a combination of experience, optimism and desperation. And measuring carefully to lift the floor exactly above the living room light fitting.

Nice one....Delboy and Rodney needed a man like you,for that chandelier....

 

[HappyHippyDad]

Opening myself up here, but I have very little knowledge of the electrics outside of the domestic situation.

Am I right in thinking that at the transformer there is an earth rod (similar to a domestic one, just bigger?) in the ground and this is attached to the neutral at the transformer?

 

[Deleted member 26818]

It's Friday, I have popcorn and wine and am now awaiting Essex"s explanation as PEG rose to the challenge and gave his.

So Essex can we hear your theory for the argument on the flip side please?

I don’t see that happening, as the RA is just the resistance of the electrode and the earth conductor combined to earth.
Whereas what PEG is describing is the Ze.