Measuring Ze

[NDG Elecs]

That's what RB was alluding to in the second post.

As someone else mentioned you can use the left and right arrows to toggle between the high and low current settings. For Ze testing use two probes only on high current.

It was TJ in #26

 

[gazdkw82]

On all testers?

 

[NDG Elecs]

On all testers?

Not familiar with all testers but I would say very very likely yes. DS mentioned this also earlier that Ze is a two probe test. Look in GN or OSG for further info I would say. Ze tests between L and E. Neutral not relevant to this test.

 

[gazdkw82]

Ok I'll try it with just L and E

 

[NDG Elecs]

Isolate CU, disconnect main earth at CU, test between that and live at incoming side of main switch. Make sure your tester is set to high current for a more accurate reading. The neutral connection only comes into it when there is an RCD involved as far as I aware. Others may know better.

 

[Paul.M]

The manual is very basic. There is a diagram, that's about as much info as you get.

View attachment 32230

Gaz your getting Zs & Ze confused mate. (going by the picture you posted up)

The MI3000 on screen display shows you how many probes to use and which probes to use on every test you perform. Select any test function and have a look at the bottom right hand side of the display screen. Three circles L, N & PE. If the circle is solid/black then you need to attach a probe to that test lead. eg:-

Zs = a 3 probe test. Pre-select the type of MCB (eg bs60898 32A), plug in using an adapter (safer than using probes btw) and it will give you a reading and work out if it is acceptable to AMD3 Regs for you.

Ze = a 2 probe test taken at the DB with the probes on Line and Earth. Have a look at the bottom right display screen before any test just to make sure you have set it up correctly.


When carrying out a Zs and the MFT prevents you from doing so, a X will appear. This is due to earth leakage from energized circuits whilst trying to test. With permission (etc, etc, etc) turn off the main switch and conduct the Ze test. Now find out where the leakage is coming from lol.

The lads at Test Meter can answer this question a lot better than most of us on here regarding your Metral, send them a PM and I'm sure they will be happy to help.

 

[HappyHippyDad]

I couldn't get a reading, using an MFT1730 tester, using three wires. The tester would start to test but then stop and read >50V. I managed to get a reading using the 2 wire method.

Any ideas?

I have just checked the Instruction manual Gaz and the picture does show 3 leads (see top of page 39 http://www.test-meter.co.uk/images/file/Metrel MI3000.pdf), however it does state clearly that this is a (earth) 'fault loop impedance test' and not an external earth fault loop impedance check.

You would need to connect your L3-PE lead into the back of the L2-N and then test at the main switch between Line and disconnected main earth with the 2 remaining leads.

 

[gazdkw82]

as far as the tester is concerned isnt it the same thing?

there is no function labelled ze. In the manual you have linked to it says the loop function performs 2 tests. Z loop for RCD and Z loop. I just assumed that Z function was for Ze and Zs