identifying systems

[malawi]

hi guys i have asked a similar question last week regarding identifying tns or tnc-s systems if not clearly visible .i have 2392 and hopefully would like to pass 2391 in future so have practising on my brothers high rise flat .when i asked before i was kindly told to do pefc and pscc tests and if same it was tnc-s .i done both tests and got PEFC 1.64KA and PSCC 1.99KA .how close do these readings need to be to identify TNS or TNC-S any help would be greatly appreciated thanks in advance

 

[acat]

What was your Ze reading that would help in deciding or as a last resort ring your DNO as they have that information.


Hope that helps


Chris

 

[Sintra]

hi guys i have asked a similar question last week regarding identifying tns or tnc-s systems if not clearly visible .i have 2392 and hopefully would like to pass 2391 in future so have practising on my brothers high rise flat .when i asked before i was kindly told to do pefc and pscc tests and if same it was tnc-s .i done both tests and got PEFC 1.64KA and PSCC 1.99KA .how close do these readings need to be to identify TNS or TNC-S any help would be greatly appreciated thanks in advance

Doing PEFC and PSCC tests can be misleading as all bonding will be in place giving parallel earth paths.

Try doing the same tests with the installation isolated and bonding disconnected. If TNC-S the readings will be the same.

 

[malawi]

cheers guys ZE was 0.13 ohms

 

[acat]

That would suggest TNCS as max on that is 0.35 TNS is 0.8 and I would think if you followed the above advice your short circuit and fault readings would be the same.

Hope that helps


Chris

 

[malawi]

thanks for the help guys much appreciated

 

[JUD]

That would suggest TNCS as max on that is 0.35 TNS is 0.8 and I would think if you followed the above advice your short circuit and fault readings would be the same.

Hope that helps


Chris

Not necessarily. My sister's TNS supply has a Ze of 0.09Ω

 

[acat]

Thats why I used the words "That would suggest" rather than that is"


Chris