Neutral - Earth Link in Main Switchboard

Hi Clive S

Which country  are you from, and how many wires come in from the supply company ?

Here (UK ) a single phase 230V supply  is normally 2 wires  (Live and Neutral, no company provided earth) or 3 wires (Live Neutral and a CPC = Circuit Protective Conductor = A wire for the ground/ earth connection.)


If the company does not provide an earth you must not connect your private earth to the company neutral.


3 phase supplies, common in larger buildings, are 4 wires or 5.

There is an alphabet soup of shorthand...


Now to make sure fuses will blow,  and the ADS (Automatic Disconnection Supply ) occurs in an earth  fault condition the CPC is connected to neutral, but  this link is supposed to be in the supply company equipment, not the consumer's - in fact to share the two functions of CPC (earth) and Neutral by a single wire is not permitted on the consumer side of the puibic supply, by UK law.


IF the supply company distribution has the NE bond at the transformer, and then separated N and E to each consumer that is TN-S , if it is combined,and the splitting of the neutral to be a neutral and  a CPC is done at or near each property, that is TN C  (French, Terra/neutral separe  and Terra/Neutral combine)

TNC-s is a short hand for neutral  and earth combined for the big stuff outside, and separated at the consumer side, common in newer towns and where rewiring of street mains has occurred. PME - protective multiple earthing, is another name for the same system, where for distribution, earth and neutral are combined, with lots of earth electrodes along the path of the neutral (PEN) - Protective Earth and Neutral.

Hi Clive S

Which country  are you from, and how many wires come in from the supply company ?

Here (UK ) a single phase 230V supply  is normally 2 wires  (Live and Neutral, no company provided earth) or 3 wires (Live Neutral and a CPC = Circuit Protective Conductor = A wire for the ground/ earth connection.)


If the company does not provide an earth you must not connect your private earth to the company neutral.


3 phase supplies, common in larger buildings, are 4 wires or 5.

There is an alphabet soup of shorthand...


Now to make sure fuses will blow,  and the ADS (Automatic Disconnection Supply ) occurs in an earth  fault condition the CPC is connected to neutral, but  this link is supposed to be in the supply company equipment, not the consumer's - in fact to share the two functions of CPC (earth) and Neutral by a single wire is not permitted on the consumer side of the puibic supply, by UK law.


IF the supply company distribution has the NE bond at the transformer, and then separated N and E to each consumer that is TN-S , if it is combined,and the splitting of the neutral to be a neutral and  a CPC is done at or near each property, that is TN C  (French, Terra/neutral separe  and Terra/Neutral combine)

TNC-s is a short hand for neutral  and earth combined for the big stuff outside, and separated at the consumer side, common in newer towns and where rewiring of street mains has occurred. PME - protective multiple earthing, is another name for the same system, where for distribution, earth and neutral are combined, with lots of earth electrodes along the path of the neutral (PEN) - Protective Earth and Neutral.