Please can someone confirm if this is a TNS earthing?  (and not TN-C-S)

This is a picture from the outside mains distribution board on my street.  I'm in South Africa.

Below is a picture of my home distribution board.

45 minutes ago, MPAD said:

Please can someone confirm if this is a TNS earthing?  (and not TN-C-S)

This is a picture from the outside mains distribution board on my street.  I'm in South Africa.

Below is a picture of my home distribution board.

Here is a TN-C-S kindly provided by @TaliaB

The kiosk has a separate earth and neutral bar so I take it as TN-C-S. Each consumer is fed with a L N E. No further N to E bonding. 

If you have a TN-S you will be measuring the resistance of the neutral back to the Tx and the armour from the TX back to the earth terminal. This reading should be roughly the same as Ze, about 0.1 to 0.3 ohms.
If you have a TN-C-S, you will only be measuring the resistance of the neutral tail, which should be 0.00 ohms on your meter (less than 0.002 in reality). But you need a Installation tester to do this measurement a normal multimeter would not suffice.

1 hour ago, MPAD said:

Please can someone confirm if this is a TNS earthing?  (and not TN-C-S)

This is a picture from the outside mains distribution board on my street.  I'm in South Africa.

Below is a picture of my home distribution board.

How did you measure the 0.22ohms if measured correctly that indicates that it is a TN-S earthing system.

@MPAD if you have a installation multitester then it is best to do all the test to determine the state of the wiring external(Ze) and combined(Ze+Zs). Do earth loop impedance of Ze( point of supply to tx) Then do Neutral loop impedance. Do Pfc(prospective fault current) and lastly Pscc( prospective short curcuit current). Take the highest value between Pfc and Pscc and ensure all breakers ka rating is higher than the result obtained from above current test.

Edited August 3, 20233 yr by TaliaB

47 minutes ago, TaliaB said:

How did you measure the 0.22ohms if measured correctly that indicates that it is a TN-S earthing system.

With a multimeter set on continuity between the 2 blue points in diagram (one lead on the circuit breaker where neutral first arrives and other lead on busbar where earth first arrives)

Edited August 3, 20233 yr by MPAD
spelling error

7 minutes ago, MPAD said:

With a multimeter set on continuity between the 2 blue points in diagram (one lead on the circuit breaker where neutral first arrives and other load on busbar where earth first arrives)

You have a TN-S earthing system. Like i said above to be sure use a installation multitester and do loop impedance test on the live installation from where it enters the building back to the supply Tx.(Ze)

Edited August 3, 20233 yr by TaliaB

10 hours ago, TaliaB said:

You have a TN-S earthing system. Like i said above to be sure use a installation multitester and do loop impedance test on the live installation from where it enters the building back to the supply Tx.(Ze)

I thought from these two figures below (from Annex J - SANS 10142) I would just be able to look at the distribution board on my street (source of energy/source earth??) and if N and PE are separate then it a TNS?  Am I missing something?

 

 

 

 

 

 

Edited August 4, 20233 yr by MPAD
remove additional figure

1 hour ago, MPAD said:

I thought from these two figures below (from Annex J - SANS 10142) I would just be able to look at the distribution board on my street (source of energy/source earth??) and if N and PE are separate then it a TNS?  Am I missing something?

 

 

 

 

 

It depends the reason you need to know the earthing arrangement it might be your earth neutral bridge is upstream from your kiosk in the street and it is not visible. There's an associated term "PME" - Protective multiple earth - which simply means that the distribution network earths the neutral at multiple points along the way.  Which tries to ensure that the earth is not lost.  The correct way of determining the earthinging system is by measuring it hence the reason i said to use earth fault loop impedance test.

All the other tests i mentioned is if you want to check the complete installation status. 

Edited August 4, 20233 yr by TaliaB