TN-C-S or TN-S?

[P&Q]

Hi everyone,
Just wanting to confirm something, could you please let me know if these pictures are describing a TN-S or TN-C-S system?
Thanks in advance

 

[truckster]

Looks TN-S to me

 

[mattmoo1974]

TNS! my friend
Paper wrapped and straight to the MET

 

[malcolmsanford]

I would say they are both TN-S systems to be honest, though the one on the right as a sticker next to the earth terminal, which I can't read., which sometimes denotes a TNC-S.

Best way to test, Ze and if you have a low reading below 0.20ohm then most likely TNC-S anything above 0.35 and then I would go for TN-S

You can also do a PEFC and a PSCC test and if they are basically the same you will have a TNC-S

 

[Guest123]

They both appear to be TN-S as the main earthing facility is via the suppliers cable sheath.

Although pic 2 does not appear to have a main earthing conductor attached to the MET adjacent to the supply cable???

 

[Goody]

Looks like the braided cable is attached to the sheath on the DNO cut out - must be a TNS system.

 

[P&Q]

Thanks for your reply, I thought they were TN-S too. But in the 2nd picture it's a customer's house where they had no earth, so we requested the DNO put in a
PME, which they did, and a PME is described as Protective Multiple Earthing System, which sounds like a TN-C-S? and this picture is showing the situation after a PME was put in.
So I'm not sure now, which is why I decided to ask you guys.
Thanks

 

[P&Q]

The 1st picture is showing a previous job I did, and I thought that was a TN-S and then I came across this second job and that's a TN-C-S system, and from what I understand, both these systems are the same they look like the same thing is happening, could you please explain how I can tell they are different? I would appreciate that.

 

[mattmoo1974]

As lenny said, I hope Number 2 was pre "Its alive a live 0"

 

[P&Q]

I would say they are both TN-S systems to be honest, though the one on the right as a sticker next to the earth terminal, which I can't read., which sometimes denotes a TNC-S.

Best way to test, Ze and if you have a low reading below 0.20ohm then most likely TNC-S anything above 0.35 and then I would go for TN-S

You can also do a PEFC and a PSCC test and if they are basically the same you will have a TNC-S

Thanks for your reply,
First picture: Ze 0.32, PEFC 1kA

 

[BES]

pic 1 def tns
pic2 ? says pme on label but still looks like braided cable from sheath goes to met so tns .tncs should be at main cut out or so i thought.

 

[High Tower]

Easy way to tell is on a TNC-S the PSCC and PEFC will be near enough the same

 

[P&Q]

Easy way to tell is on a TNC-S the PSCC and PEFC will be near enough the same

Thank you

 

[P&Q]

As lenny said, I hope Number 2 was pre "Its alive a live 0"

I took photo 20 min after DNO did PME!

 

[PC Electrics]

The Ze reading is no reliable indication of whether it's TN-S or TN-C-S, IMO. There is a large 60's estate near me where every house is a TNS. There are sub-stations sprinkled across the estate and I've got Ze readings between 0.08 and 0.23 in various houses.
This is the cutout fitted in these houses:
TN-S not TN-C-S - Shared photo album - PhotoBox