metrel mi3000 testing for ze

[Kelrich]

evening everyone
Iam doing some testing and ive done my IR test, continuity of protective conductors, continuity of rfc and a earth fault loop impedance no problems but my metrel mi3000 wont allow me to test for Ze anybody know what settings it should be, am testing a domestic split load consumer unit.
thanks in advance

 

[Deleted member 26818]

You switch the left hand rotary switch to Loop Uc, connect the 3 test leads, make sure it's not set to 'RCD' and test away.

 

[Kelrich]

alright spinlondon

i have tried all this and no joy, ive turned the dial to loop and my options on screen are: Zs, or Zsrcd. I have tried both of these and still no joy, ive even been on the Metrel website and their screen shows loop where my screen shows the above and there is no function to change it.

 

[Guest123]

Are you on a TT system???

Many testers wont allow you to carry out the Ze test if your earth path is overly poor where the touch voltage of 50V would be exceeded when the test was carried out.

 

[Deleted member 26818]

It should show Z loop or Z loop (RCD).
Perhaps yours shows Zs and Zs (RCD) instead.
Either way, Ze and Zs are the same test, just one is conducted at the origin of the installation, with the earth conductor disconnected from the installation, and the other at the end of circuits.

Lenny, the OP says they've conducted the EFLI test with no problems, so there should be nothing preventing them conducting the same test at the origin of the installation.
It's most likely that they are placing the probes on the load side of the main switch.

 

[Kelrich]

Basically i removed the main earth from the earthing bar and attached my green croc clip to it, then placed my brown croc clip to the supply line and my blue croc clip to the supply neutral i then put my meter onto loop, the screen reads Zs or Zsrcd. I pressed test on both of these settings and got nothing so i removed both the brown and blue croc clips and changed them to the probes and placed these probes onto the line and neutral terminals on the main supply switch and again got nothing. Where am i going wrong??????????grrrrr!

 

[esc]

Hi kelrich, i have a similar prob with a friends installation, i put the post on yesterday "this is odd". I can get a Zs from a SO, but when i try get a Ze, meter wont test. I have a metrel similar to yours and it has a display giving PD between L & N and L & E prior to test. The readings i get are very odd. Thought it might be leads, but they're ok.
Theres some views on the post that marry up somewhat with lenny's above and others. Av a look.

 

[Deleted member 26818]

Have you got the main switch off?
Does the meter show a tick to test, or a cross?

 

[cakey]

Turn of main switch.
Disconnect main earth conductor.
Switch to LINE!!
Metrel requires 3 lead test so connect blue and green of test lead together with croc clip onto earth conductor.
Connect Brown test probe to supply line on main switch and test.

Was told loop was for zs test and line for ze. Bit odd but that's the French for you. Always worked for me.... Good luck

 

[Deleted member 26818]

Line is for testing PSCC, not PEFC or Ze, and the test should be conducted with the earth conductor re-connected.
Both are 3 lead tests, all 3 leads should be connected to there respective conductors, you should not connect the blue and green leads together.
You should test both to obtain PFC.
Metrel are Latvian not French.
Here's a link to the instructionmanual: http://www.metrel.co.uk/fileadmin/B...otestEasi_PLUS_UK_HW_3_Ver_1.1_20_751_466.pdf

 

[cakey]

Brilliant spinlondon. That's main earth removed for ze test and connected for pfc and pscc....

 

[Guest123]

Lenny, the OP says they've conducted the EFLI test with no problems, so there should be nothing preventing them conducting the same test at the origin of the installation.
It's most likely that they are placing the probes on the load side of the main switch.

If he has successfully conducted a Zs measurement, the reading may have been obtained via parallel paths. Obviously with the Ze, it's MEC disconnected so as I said there MAY be an issue with the earthing system to the property.

 

[Kelrich]

alright lads thanks very much for the helpful replies.
i have tried the same test in my own house as well as my grandads house and i get the same, nothing no tick or an X onthe screen its like it dosent want to know, like i said on the metrel website they diagrams show the wording LOOP on screen where as mine shows Ze or Zercd. my readings are as follows;

continuity of circuit protective conductors
highest result = 0.6 ohms

IR test
L-N = 1000 ohms
L-E = 1000 ohms
N-E = 1000 ohms

continuity of rfc
R1 = 0.2
R2 = 0.2
RN = 0.3
R1+R2 = 27.9 furthest socket from cu
R1+RN = 0.1 furthest socket from cu

LIVE TESTS
EARTH FAULT LOOP IMPEDANCE zs
used my plug in test lead
reading of 0.44 ohms

LINE IMPEDANCE
used my plug in test lead
reading of 0.29 ohms

PROSPECTIVE FAULT CURRENT
800A

VOLTAGE AND FREQUENCY
U1- L-N= 241V
U1+PE- L+E= 241V
UN-PE- N+E= 0V
FREQ= 50.1HZ
bear in mind Iam just a beginner and I have alot more testing to do but these all seemed ok.
also main earth (16mm) renewed and gas and water (10mm) also renewed and the system is a tnc, am i right in thinking that the Ze reading must go on test cert if yes how on earth am i meant to get it when meter wont play.
any help would be greatly appriciated thanks

 

[Deleted member 26818]

Have you tried to conduct a Zs test using the probes, say at the back of a socket-outlet, or at a light fitting, rather than using the 3pin plug lead?
Just wondering if there's a fault on your probe leads.
To be honest with you, the only things I can think of, is that either there is a problem with your leads, or you are placing the probes incorrectly, perhaps on the load side of the main switch, rather than on the supply side.

 

[Kelrich]

cheers spinlondon
I will try this when i get home and let you know the outcome, i thought maybe it was me not setting the meter correctly but ive followed the exact procedure that metrel use on the website only difference is the screen, also i definatly placed the probes onto supply, its crazy when everything else seems to be working

 

[Guest123]

continuity of rfc
R1 = 0.2
R2 = 0.2
RN = 0.3
R1+R2 = 27.9 furthest socket from cu
R1+RN = 0.1 furthest socket from cu

Could you explain how you obtained these reading a bit more please,.....they really don't add up at all????

 

[Kelrich]

Sorry lenny ive given you the wrong readings there i,ll get back to you tomorrow as i am out at the moment

 

[Kelrich]

Alright lads
lenny ive popped back to re do the rfc test and got practically the same readings
R1=0.2
R2=0.2
RN=0,1
then connected incoming line to outgoing earth and outgoing line to incoming earth
R1+R2= 29.9 fail
then changed my earths to the neutrals and got
R1+RN= 0.0
any ideas whats up and do i have to rectify the problem for my cu assessment?

 

[Octopus]

Alright lads
lenny ive popped back to re do the rfc test and got practically the same readings
R1=0.2
R2=0.2
RN=0,1
then connected incoming line to outgoing earth and outgoing line to incoming earth
R1+R2= 29.9 fail
then changed my earths to the neutrals and got
R1+RN= 0.0
any ideas whats up and do i have to rectify the problem for my cu assessment?

Are you sure you have the ends of the ring correctly identified?

 

[Deleted member 26818]

Alright lads
lenny ive popped back to re do the rfc test and got practically the same readings
R1=0.2
R2=0.2
RN=0,1
then connected incoming line to outgoing earth and outgoing line to incoming earth
R1+R2= 29.9 fail
then changed my earths to the neutrals and got
R1+RN= 0.0
any ideas whats up and do i have to rectify the problem for my cu assessment?

It sounds to me that at one of the socket-outlets the CPC and neutral are swopped over.

 

[Octopus]

It sounds to me that at one of the socket-outlets the CPC and neutral are swopped over.

Possibly but that doesn't explain the end to end readings though!

 

[Kelrich]

Cheers fellas
i,ll check the sockets as customer has said about ten years ago the kitchen was wired in by a relative so hopefully the problem lies in there

 

[Deleted member 26818]

I can't see a problem with the end to end readings?

 

[Octopus]

I can't see a problem with the end to end readings?

No, I agree but if two cables were swapped you'd expect the end to end readings to be very similar.

Looks a bit fishy though. lol

 

[REIBURN]

hi i have the metrel mi3000 easi test and one of the lads i work with did a ze test using my meter set to loop z (rcd) he went between the live neutral of the main switch and earth and said that the meter froze. I have checked all the fuses and nothing has blown but i cant get to loop rcd anymore. any ideas? please help!

 

[Deleted member 26818]

I sometimes have problems, doing Zs tests, if the contact with the probes is not very good.
If your meter has frozen, try removing the batteries, leaving a couple of minutes (have a cup of tea or something) and the replace the baterries and re-try.
If that doesn't work, then you will have to return the unit for repair.

 

[Guest123]

Have you tried the universal method of repair......blowing on it???:lol:


I'd agree with spin above though, if pulling the batteries out doesn't cure it you may have to send it away.

 

[REIBURN]

I sometimes have problems, doing Zs tests, if the contact with the probes is not very good.
If your meter has frozen, try removing the batteries, leaving a couple of minutes (have a cup of tea or something) and the replace the baterries and re-try.
If that doesn't work, then you will have to return the unit for repair.

thanks iv tryed doing that and still no joy. i just wanted to make sure that before i send it back that its not something that would void the warrenty. also wheres the thanks buttons im new to this!

 

[Octopus]

thanks iv tryed doing that and still no joy. i just wanted to make sure that before i send it back that its not something that would void the warrenty. also wheres the thanks buttons im new to this!

Along the bottom of each post is a brown "bar". At the left hand end is the "thanks" button.

 

[silverfox1]

Hi just a thought but is it set to test TN/TT in settings menu.To access settings menu press backlight key and turn function selector switch,to leave set up rotate selector switch again.

 

[resettleddave]

Hi kelrich, i have a similar prob with a friends installation, i put the post on yesterday "this is odd". I can get a Zs from a SO, but when i try get a Ze, meter wont test. I have a metrel similar to yours and it has a display giving PD between L & N and L & E prior to test. The readings i get are very odd. Thought it might be leads, but they're ok.
Theres some views on the post that marry up somewhat with lenny's above and others. Av a look.

esc

I have a Metrel MI3100 and a similar thing happened to me today, Ze test with earth conductor disconnected - PD between L-E 210v, PD between N-E 42v, total 252v - Metrel refused to test with error message of unrecognised supply. Reconnected earth conductor and re-tested works fine with sensible reading and PDs 230v and 0v as expected. Did you ever get a conclusive answer as to what was happening in your case?

 

[Octopus]

esc

I have a Metrel MI3100 and a similar thing happened to me today, Ze test with earth conductor disconnected - PD between L-E 210v, PD between N-E 42v, total 252v - Metrel refused to test with error message of unrecognised supply. Reconnected earth conductor and re-tested works fine with sensible reading and PDs 230v and 0v as expected. Did you ever get a conclusive answer as to what was happening in your case?

Are you sayoing you tried the Ze with out connecting the earth lead? It sounds like you did - you need to disconnect the main earth (from the MET or CU) to prevent parrallel paths and at the same time remember to connect the earth lead to the "loose" main earth. obviously you'll have turned off the power to the building first!

 

[ackbarthestar]

I've had similarly odd results from my Metrel. The Eurotest is generally a very good instrument, but I have found that sometimes the results begin to become inconsistent.

You definitely need to use the 3 leads when loop testing ,whether or not you link the blue and green leads together to reference the neutral and earth is up to you. If the green lead fails then you will still be able to dead test but you will get inconsistent/ no result for loop testing.

My problem was found when I checked the resistance of the connections with a multimeter. Both times with 2 separate sets of leads I found that the green conductor at the point of the joint in the plug had frayed and broken off.

 

[resettleddave]

Are you sayoing you tried the Ze with out connecting the earth lead? It sounds like you did - you need to disconnect the main earth (from the MET or CU) to prevent parrallel paths and at the same time remember to connect the earth lead to the "loose" main earth. obviously you'll have turned off the power to the building first!

I definitely connected all three test leads and in the correct configuration including the green lead to the disconnected earth conductor, so I was happy that I was doing the test correctly for Ze, Tried it several times aswell always the same. Reconnect earth conductor to DB earth bar and test with green croc on earth bar and good reading, but this is obviously not Ze (parallel paths etc..).

Based on similar threads, it just seems to be a common occurance with this family of Metrel testers, I will ring Metrel and see if they have an answer, if I get one I will post it.

cheers

 

[timbobelfast]

No problems with my Metrel. Although it is a 3 lead test for for as stated already.

 

[Octopus]

I definitely connected all three test leads and in the correct configuration including the green lead to the disconnected earth conductor, so I was happy that I was doing the test correctly for Ze, Tried it several times aswell always the same. Reconnect earth conductor to DB earth bar and test with green croc on earth bar and good reading, but this is obviously not Ze (parallel paths etc..).

Based on similar threads, it just seems to be a common occurance with this family of Metrel testers, I will ring Metrel and see if they have an answer, if I get one I will post it.

cheers

The only time my metrel has done this I discovered the TNS clamp wasn't actually connected to the earth at all!

 

[cymroaur]

Re-awakening an old thread!



Same problem here. This is what my tester gave me when trying to do a Ze on a TT system. Zs readings were fine, and Ze without the earth connected gave a >2000ohm reading. Any suggestions?

 

[Octopus]

Re-awakening an old thread!

View attachment 12490

Same problem here. This is what my tester gave me when trying to do a Ze on a TT system. Zs readings were fine, and Ze without the earth connected gave a >2000ohm reading. Any suggestions?

Presumably the metrel was connected to the cable going to the spike??

 

[cymroaur]

Presumably the metrel was connected to the cable going to the spike??

Wasn't the first time (doh!). Definitely was the second time, and threw said wobbler.

 

[Spazz]

I know this is a bit old - but might be of use to someone

I have the same problem right now! Called Mertal up and they said Fuse 1 (F1) has blown - replace it and all will be fine.

 

[CLB]

You can reset the Metrel3000 back to it's factory state by holding down the right arrow key and then switching it on. Mine froze a couple of days ago and the manual that came with (on the cd) said how to reset it and it worked fine after that.
And yes, it has Loop Z for Ze readings. Earth croc onto disconnected supply earth, L & N test leads onto L & N terminals of the supply and got 0.14ohms. However, if you use the plug lead for testing for earth faults at a socket outlet you have to set it to Loop Z(RCD) which prevents the rcd tripping.
(Reset info is on p21/22 of the user manual http://bit.ly/NDcPJZ )

 

[richy3333]

Thought only Megger's had problems according to the forum? :devil:

 

[the pict]

And have you zero'd your leads first,
Pict

 

[drew35]

With the metrel you need to lose that 2v N to PE before it will test, you should just get the beep of refusal if you press the test button. And if you cant get a reading you need to put all your weight behind the probes to get a good enough contact.
I opened one of these Metrel's up once and inside its the same as one of those lottery pens that have all the balls in the top. You shake the pen and get a random six numbers, the Metrel works on the same principle with a bit of magic eight ball thrown in!!! Try doing the same test several times and you get vastly different readings, they should stick to making calculators and children's toys!

 

[CLB]

And if you cant get a reading you need to put all your weight behind the probes to get a good enough contact.

Or you could just temporarily remove the protective shrouds on the tips of the probes :yes:

 

[drew35]

Or you could just temporarily remove the protective shrouds on the tips of the probes :yes:

Eh??? For a start what protective shrouds! You need to push hard to get a good contact it doesn't matter if you have the shrouds on or not! If the machine beeps and fails to take a reading, or you get a high reading, push hard, I have this machine I should know!!! F wit...

 

[CLB]

Eh??? For a start what protective shrouds! You need to push hard to get a good contact it doesn't matter if you have the shrouds on or not! If the machine beeps and fails to take a reading, or you get a high reading, push hard, I have this machine I should know!!! F wit...

As do I, and my test probes have removable plastic tips so that more than 2mm of the tip is exposed. You're just making hard work for yourself. Or maybe you should buy a new one, or have your one recalibrated (you do know about that don't you? Of course you do).