metrel mi3000 testing for ze

[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://------/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: