uksparks
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Hi,
If you have a TNS supply, you would have a separate earth path by way of lead pipe or split concentric etc... true?
Ok, so if you have a PME / TMC-S supply, the earth connects to the neutral at the service head, yes... true?
Ok, so just out of interest, if you had an overhead TT thats now been converted into a PME, would you expect the PFC and PSCC readings to fluctuate if you keep taking the reading?
I just changed a board yesterday on this supply, and it was overhead TT, now PME, and im getting fluctuating readings anywhere from 0.22 to 0.28, ive checked my meter and checked again etc, and its all ok, but its fluctuating.
The only reason I say this is because, i also changed a board i dont know 6 months ago, i put it down as TNC-S / PME as thats exactly what I saw, the readings between PFC and PSCC were 0.1 ohms different. The NICEIC bloke said You are wrong, its not TNC-S and marked me down.
I said ok, well what is it then? He said its TNS on split concentric cable...ok fair point I said, he said that if its PME / TNC-S the readings will be exactly the same.
Now this one I have just done, its quite clean cut, theres two lines and one neutral, its NOT TNS, its not possible, but I am getting fluctuating readings.
Can anyone with a bit more knowledge enlighten me please.
I have connected the Earth into the left hand side as instructed by WPD as its been converted to PME and even has a sticker on it saying TNC-S / PME.
If you have a TNS supply, you would have a separate earth path by way of lead pipe or split concentric etc... true?
Ok, so if you have a PME / TMC-S supply, the earth connects to the neutral at the service head, yes... true?
Ok, so just out of interest, if you had an overhead TT thats now been converted into a PME, would you expect the PFC and PSCC readings to fluctuate if you keep taking the reading?
I just changed a board yesterday on this supply, and it was overhead TT, now PME, and im getting fluctuating readings anywhere from 0.22 to 0.28, ive checked my meter and checked again etc, and its all ok, but its fluctuating.
The only reason I say this is because, i also changed a board i dont know 6 months ago, i put it down as TNC-S / PME as thats exactly what I saw, the readings between PFC and PSCC were 0.1 ohms different. The NICEIC bloke said You are wrong, its not TNC-S and marked me down.
I said ok, well what is it then? He said its TNS on split concentric cable...ok fair point I said, he said that if its PME / TNC-S the readings will be exactly the same.
Now this one I have just done, its quite clean cut, theres two lines and one neutral, its NOT TNS, its not possible, but I am getting fluctuating readings.
Can anyone with a bit more knowledge enlighten me please.
I have connected the Earth into the left hand side as instructed by WPD as its been converted to PME and even has a sticker on it saying TNC-S / PME.