TN-C-S or TN-S ???

[Liam12]

Came across this on a rewire, looks to me like a TN-C-S, but had SNE on the side as you can see, we thought as the sheathing was metal it could mean (seperate neutral & earth) and be a TN-S, never seen before and could just be coincidence, a point in the right direction would be handy, cheers.

 

[Marnik]

Forgive me if I am wrong but are Ze and PSCC not directly related via ohms law?

Yes, but they're not the same,are they?

 

[snowhead]

justed looked at that, could be used for both TN-S and TN-C-S ???

Different N/E or N + E blocks are fitted, covers are different colours to identify;

http://www.cooperbussmann.com/pdf/7fe5eb03-9fef-41d7-b080-3e2a366ea1f2.pdf

 

[SYKRAPS]

Yes, but they're not the same,are they?

Clearly I agree they are different but in a PME system both the Ze and the PSCC will be almost identical measured as I mentioned in my 1st post, and more than likely different in a TN-S setup.

You agree?

 

[SJD]

Clearly I agree they are different but in a PME system both the Ze and the PSCC will be almost identical measured as I mentioned in my 1st post, and more than likely different in a TN-S setup.

You agree?

Ze is measured in Ohms, PSCC & PEFC are measured in Amps / kA !

 

[Marnik]

Clearly I agree they are different but in a PME system both the Ze and the PSCC will be almost identical measured as I mentioned in my 1st post, and more than likely different in a TN-S setup.

You agree?

No , In a PME system both PEFC and PSCC will be identical, NOT Ze and PSCC !!! where on earth do you guys get this from????
Tell me,what is the relation between Ze, PEFC and PSCC ?? Please come on guys

 

[bugsy]

It's PME

 

[Marnik]

Ze = external loop impedance(measured between L-E on incoming side, with E disconnected) PEFC = Prospective earth fault current (Uo/Ze L-E) PSCC = Prospective short circuit current (Uo/Ze L-N) measured on load side with all conductors connected
hope this clears it up

 

[SYKRAPS]

No , In a PME system both PEFC and PSCC will be identical, NOT Ze and PSCC !!! where on earth do you guys get this from????
Tell me,what is the relation between Ze, PEFC and PSCC ?? Please come on guys

I am not saying that the readings for Ze and PSCC will be the same as they are measured in Ohms and KA respectively, I am saying that if you test as I said in my original post that in a PME system if you measure Ze with prongs to L, N and Earth you will get the same reading in Ohms as you would connecting you L prong to L and your N and Earth prongs to N............if the results are different then it will be TN-S.

I am not disagreeing with your comment i just feel mine is also correct.

Surely the relationship between Ze and PSCC is V=PSCC*Ze

i.e. If PSCC=0.96 KA and Ze=0.25 Ohms then V=240 Volts.....................Right?

 

[bugsy]

Ze = external loop impedance(measured between L-E on incoming side, with E disconnected) PEFC = Prospective earth fault current (Uo/Ze L-E) PSCC = Prospective short circuit current (Uo/Ze L-N) measured on load side with all conductors connected
hope this clears it up

Cut the crap Marnik's right and it's pme , tns cable reported with with high values converted to pme!

 

[Guest55]

its not PME , its TN-C-S !


* runs off and hides behind sofa.

 

[bugsy]

its not PME , its TN-C-S !


* runs off and hides behind sofa.

Idont run and hide anywhere it's kin PME

 

[bugsy]

Forgive me if I am wrong but are Ze and PSCC not directly related via ohms law?

Yes, but they're not the same,are they?

do me a favour - phone the dno and ask them if im wrong i'll donate £100.00 to help for hero's

 

[Guest55]

.... it's kin PME

maybe you should re-read the definitions then.
pme is the delivery method used by the dno for supply
tn-c-s is the earthing arrangement provided by the dno at the users installation.
big difference.

 

[bugsy]

maybe you should re-read the definitions then.
pme is the delivery method used by the dno for supply
tn-c-s is the earthing arrangement provided by the dno at the users installation.
big difference.

Plonka - tn-c-s is PME - try asking the DNO!

 

[sparks1973]

PSCC wouldn`t be anything to do with Ze anyway...
Zpn/Zpp more like...