Earth rod testing the easy way?!

[RISElectrical]

Any one used the clamp type earth electrode testers? No disconnecting and simple clamp on test.Asked fluke for a trial for a week however they declined. Meggar also make one. Link to fluke below.Fluke Electronic Test Tool Products have A lot of rod testing to come soon and looking for a quicker way that the 3/4 pole methods

 

[Marvo]

I think the link you gave may have been a search result that was held in server cache. Can you give another link to a specific web page URL please?

 

[johnboy6083]

The best way for me is the fall of potential method.

 

[RISElectrical]

Megger DET24C Earth Resistance Clamp Meter - Stakeless Earth Testing

Meggar version. Sorry about fluke link. Some of the places I will need to test are in the middle of a fully tarmaced car park.

 

[johnboy6083]

Download the megger guide to earth rod testing. It suggests that you can use street furniture as test rods, and if your stuck, even wet chains coiled on the ground. Apparently the test rods don't need a brilliant contact with the ground to get a reading.

 

[Marvo]

Wow, those things are nearly a thousand quid!!

I can't comment on how good they are, that type of cutting edge technology will be another year or two before it reaches suppliers

 

[johnboy6083]

I've just read the link, does it work in a similar way to a loop tester?

 

[RISElectrical]

I know a few lightning inspection companies that use these clamp meters, takes 5 mins per earth rod and they can test a multitude of sites a day using these. £1000 doesn't seem to bad when you can increase productivity in such a way

 

[RISElectrical]

Induces through 1 side of coil and reads the resistance back through the other side. Also giving leakage to earth. I know about using street furniture etc but in a busy car park full of cars these look to be ideal

 

[johnboy6083]

That's a fair point. Are they as accurate as conventional testers?

 

[Des 56]

It seems a little puzzling at the moment to me
How the meter can read the earth resistance on a cable without disconnecting

If the earth resistance is very high and the installation has lower parrellel paths,the meter will be reading those other paths
Anyone care to explain

 

[RISElectrical]

http://www.euro-index.nl/klanten/euro/media/documenten/MEGGER_DET14C_DET24C_AN_EN.pdf

Good PDF on above tester

 

[Marvo]

If I had loads of earth rods to test and I could justify the price I'd buy one in a heartbeat.

I haven't looked yet but it might be worth checking out Testmeter who's a forum sponsor and give extra discounts to forum members.

 

[Des 56]

Thanks for that link,I have read through it quickly and can sort of grasp what they are up to
I shall keep the file and study it further another time

Very interesting,thank you RE

 

[RISElectrical]

Yeah I will be having a good read of it too. For the job I have coming up if this can really save that much time its probably going to be a worthwhile purchase if I win the contract. I wondered for weeks pricing this job how others (a few LPS companies) were able to do rod testing so cheaply. Now I think I know how!

 

[Des 56]

I wonder what thoughts IQ has on these testers,he is generally well up on most matters concerning testing,maybe he is already using them

 

[RISElectrical]

Ideally I'd love someone to give me a hands on verdict on these types of testers before and if I buy one. As I said fluke weren't too keen on lending me one to test, I imagine meggar would say the same.

 

[Engineer54]

These testers are basically very good, but totally useless for testing single earth rod installations!! They are only advantageous in multiple rod installations i'm afraid. So only very useful on the larger commercial or industrial installations!!

If someone has posted a link on these testers, it will i'm sure, state this limitation. I hope so anyway, it will save me explaining why!! ...lol!!

 

[RISElectrical]

I am looking at 1 for environments that as a minimum will have 5 rods up to a maximum of around 100.

I am aware that they are only usable really in a loop environment, however could still be used in a single rod installation using the known earth method? Having never used 1 I have no idea of accuracy and ease of use. Hoping someone could advise