Ze & Zs With A Dilog 9083P

[steptoe]

it prob just does the 2 tests after each other,  :C

I suppose it means you dont have to press the button a second time, it just takes twice as long if you only want to do the one test.....

 

[NozSpark]

What? So it disconnects and then reconnects the earthing conductor all by itself? ??

 

[sprocketflup]

But you can't take a PSCC reading at the sane tims as a PEFC reading

....well you can but its pointless

the 2 figures could be calculated tho, could they not?

 

[steptoe]

What? So it disconnects and then reconnects the earthing conductor all by itself? ??

AH, THATS A point,

:|

:coat

 

[Doc Hudson]

John - sorry i fully understand the difference between the tests but its the tester thats completely confused me? All i was after was someone who has this specific tester or has used one. The reason being the first result was like 2.1 ohms and the other displayed 0.8 ohms, a big difference basically.

special location - thanks for that, its sort of explained it to me. Im guessing the first result is infact the Ze according to your link. as the second one is the line impedance

technician - if you could, it would be much appriciated

I think the moral of this thread, especially for members who have use of different makes of test meter, is that not all test meters operate in the same way or give their results in the same manner. And I am sure we all know that any testing should involve an understanding of what you are trying to test and what the expected results should be as well as how the meter should be operated. e.g. it is no good just pressing a button and having no idea about what scale a result should be in, miliohms, ohms, MegOhms or where to put the meter leads etc. As I read the thread I think Tarrantino has an idea what he should be getting but has been thrown by the way this meter outputs its results. Which also emphasizes the importance of been familiar with how your meters work and how to verify their results. If working on a fault diagnosis situation misunderstanding how your meter works could waste hours of time doing incorrect investigations. Thank you for your apology to the forum.

Doc H.

 

[pewter]

What? So it disconnects and then reconnects the earthing conductor all by itself? ??

PEFC is taken with all bonding earthing connected to get the largest result possible in Amps

Ze is taken with bonding earthing disconnected 

its all in GN3

 

[NozSpark]

PEFC is taken with all bonding earthing connected to get the largest result possible in Amps

Ze is taken with bonding earthing disconnected 

its all in GN3

Exactly,,, so how can a meter measure both at the same time?

 

[pewter]

Exactly,,, so how can a meter measure both at the same time?

it could take a PEFC and PSCC with 3 wire test (2 tests one after the other as steps described) and list 2 results.

It could not take a PEFC or PSCC  AND a Ze at the same time as you said it would need the bonding/earthing disconnected.

 

[Technician]

The batteries in the meter had packed up when I looked at the

meter last night.  I will have some by tomorrow.

The meter function is set to Zs which is (IIRC) the first click to the

right on the selector.  The display indicates in the centre in a 7

segment display, with another display resembling a meter over

the top, a common feature. These are in ohms.

At the bottom right is a smaller figure, again in a 7 segment display,

and against it (IIRC) is either PFC or PSC.

The meter has four buttons under the display, using these changes

the function.  I think it is the extreme left that alters the function from

measuring PSC to PFC.

Like I say, I need some batts & I will have them tomorrow.

Have another look at post #18.

 

[Tarrantino]

Right sorry to be a pain but im still struggling to get my head around this bloody tester. So im attempting to do my zs on a ring final circuit. I select the Zs/Ze setting on the tester and plug the plug adaptor into a socket. i press "Test" and get the following readings,

Initial screen gives me a reading of 2.6 ohms and in the bottom right a pfc of 90A and in the bottom left it says L-PE (which is above the F1 key to change the screen) if i press the F1 key i now get readings of 0.71 ohms and a psc of 324A with L-N in the bottom left of the screen.

Right and before anyone says it and id appriciate no cocky replies. i have read the instructions but im not 100% sure if im understanding what it says correctly. Idealy someone that has used or has this exact tester will be able to answer me here. But am i right in thinking the initial reading is infact my earth fault loop impedance and the second ohms (lower one) is my line impedance?

 

[Technician]

Tarrantino; It looks as if 2.6 is Zs (live) and the PFC of 90A is way too low.

Come to this later.

Clicking on function F1 the function changes to measure the fault current

as if the fault was a line to neutral fault, the first being a line to earth fault.

My suggestion is that you do a quick calculation for each, dividing 230 by

each of the reads and this will give you the fault currents for EACH setting.

2.6 ohms is very high for a socket and IIRC 1.16 is a maximum in the OSG,

after correction using appendix 14.

I hope this assists you but look at the difference between the two results on

fault current and I think anyone else on this forum will tell you that you have

a problem.

 

[Tarrantino]

Right basically its a TT system with a Zs of 2.2 ohms. There is a 30ma rcd installed on the CU. The exact reading i have obtained for the ring final circuit are Zs 3.0 ohms witha PFC of 107A and a PSC of 1.20kA. I know the reading is high for the ring final circuit but im guessing this is because of the high Zs ate the CU origin and since the circuit is covered by the 30ma rcd it is protected?

 

[apprentice87]

Hi Tarrantino,

Yep, i think you have got the meter sussed!!! Sounds right to me!!

Yes, Zs is maybe on the high side, but as you say, it is TT with a 30mA RCD for earth fault protection..

john

 

[batty]

2.2 ohms on a TT sounds very good no doubt getting a good earth down water or gas pipe as for .71 ohms that is about right for your L-N loop. So what actually is the problem?

 

[Technician]

Tarrantino; I have read the posts and it is only now that we

know it is a TT system.  If that is the case that would explain

it as John has said.