Neutral CPC short circuited in PME system, is that correct?

[mikex79]

HI
Doing a test with a voltage detector/continuity tester on live PME/TN-C-S system installation at a socket outlet either with load and without the load shows voltage between live and neutral and live and earth but live-earth seems to be short circuited and the continuity tester indicates continuity which for me means thet they are short circuited (and I recon they are short circuited ot the orgin as the system gets only one PEN conductorfrom the supplyer which acts as a neutral and CPC at the same time) but the probelem is that even if I switch off the MCB which seems to be very old type like from 20-30 years ago nothinch changes and the continuity between earth and neutral still exist. my question is if it is cused becouse the mcb may not be a double pole switch? if it safe (all appliances connected to the sockets work propelly but the question is if they are safe)? what test should i do on top of what i have dont to make sure all of above?
many thanks

 

[Spudnik]

You need to ensure main switch is off before carrying out any of the tests you describe.

You could try an IR test between all conductors and it should read clear, with the main switch off, all mcb's off.

 

[old dog]

You need to ensure main switch is off before carrying out any of the tests you describe.

You could try an IR test between all conductors and it should read clear, with the main switch off, all mcb's off.

disconnect neutral from the cu or both neutral and cpc you will find it will clear
if not you have a problem

 

[Spudnik]

disconnect neutral from the cu or both neutral and cpc you will find it will clear
if not you have a problem

No need to disconnect the neutral if the main switch is off

Or do you mean disconnect each circuit neutral and cpc to test?

 

[mikex79]

You need to ensure main switch is off before carrying out any of the tests you describe.

You could try an IR test between all conductors and it should read clear, with the main switch off, all mcb's off.

shall I disconnect the CPC and neutral conductors before I do an insulation test?

You need to ensure main switch is off before carrying out any of the tests you describe.

You could try an IR test between all conductors and it should read clear, with the main switch off, all mcb's off.

shall I disconnect the CPC and neutral conductors from the cosumer unit before I do an insulation test?

 

[old dog]

No need to disconnect the neutral if the main switch is off

Or do you mean disconnect each circuit neutral and cpc to test?

i dont normally isolate the whole board to test one circuit thats why i just focust on the circuit in question

 

[Spudnik]

i dont normally isolate the whole board to test one circuit thats why i just focust on the circuit in question

Ah. Fair point.