live Zs readings

[confused-fuse]

i wonder if he as popped the HRC fuse ?? if he as tryed to use the 2 leads for IR and Low ohms settings and used them on loop Ze/Zs reading ...

 

[confused-fuse]

according to the manual you can use 2 leads or 3 leads for loop/pfc page28 in manual

http://www.kewtechcorp.com/downloads/manuals/KT64_Manual.pdf

 

[wallyanker]

U need three leads to measure Ze, Zs, Pfc. 2 leads when measuring PSC, L to L or L to N

 

[ezzzekiel]

Meggers i think have a high and low test.

Hi test requires N&E together and line.

Low test requires LNE connected to each respective terminal.

quite true, but on both settings you wont get a reading for zs without 3 leads connected (unless my meg is a knackered one)

 

[Sintra]

You can high test on megger mft 1553 with 2 leads red & green only low tests require 3 leads.

 

[Risteard]

Meggers i think have a high and low test.

Hi test requires N&E together and line.

Standard loop impedance test (can't think is it 23A or 26A?) for Megger only requires two leads connected to line and earth respectively.

Only no trip (15mA) test requires three leads.

 

[Risteard]

Damnit I see Sintra got in ahead of me again!

 

[ezzzekiel]

yep thats right, wasnt thinking of rcd in circ and just used to doing low trip test

 

[Spudnik]

I knew what i meant

Also, you will be surprised at the different readings you get between high and low tests at the same test point.

 

[Sintra]

I knew what i meant

Also, you will be surprised at the different readings you get between high and low tests at the same test point.

If anyone is interested as to why the readings differ it's because the no trip (low) test uses a very short pulse and the RCD has significant inductance, so the observed figure is higher.

 

[Johno]

yep, i've got a megger to test high just 2 leads. 3 leads are needed when not tripping rcd

 

[bredon86]

hi everyone been using my kewtech kt64 today and have had problems when testing a live zs on the upstairs and downstairs lights both tests where tripping the main breaker so i didnt carry out the test. can anyone explain? (all othere live zs was fine)

 

[Risteard]

hi everyone been using my kewtech kt64 today and have had problems when testing a live zs on the upstairs and downstairs lights both tests where tripping the main breaker so i didnt carry out the test. can anyone explain? (all othere live zs was fine)

Is it perhaps a 6A Type B BS EN 60898 circuit breaker?

It should trip instantaneously between 18A-30A. Earth fault loop impedance test is within this range.

If you can't do low-current test then you'll need to calculate Zs.