RCD socket outlet.

Quote:


“Andy B


Back to school for you. RCDs do not limit touch voltage to 50V”


That is exactly the point I was making, you cannot connect a RCD to a circuit and installation that is not adequately earthed and bonded or else a fault elsewhere in the installation may raise the voltage of earthed equipment downstream of the RCD to dangerous levels, a RCD does not remove the requirements for basic and fault protection along with the requirement to mitigate touch voltages.


We are not even supposed to to test the RCD without doing an earth fault loop impedance test first to ensure that the circuit is adequately earthed.


The first thing you do when you arrive on site to alter or extend a circuit is to confirm the type and adequacy of the installation earthing arrangement, then you confirm if the circuit you are going to work on is fit and healthy,  so personally I walk in and visually inspect the distributors equipment, the main earth and earthing arrangement, the consumers consumer unit or fuse board, then go to the point where I want to alter or extend the circuit and do an earth loop impedance test, then if there is a RCD protecting the circuit disconnect the circuit by testing the RCD.


That process is not perfect, you may be able to see that there is a main earth conductor installed to a suppliers TN earth terminal, but in reality there could be a high resistance termination or fault rendering it useless, but you got a good loop test result due to a parallel path such as the gas pipe, that’s life.


 Andy Betteridge 

Quote:


“Andy B


Back to school for you. RCDs do not limit touch voltage to 50V”


That is exactly the point I was making, you cannot connect a RCD to a circuit and installation that is not adequately earthed and bonded or else a fault elsewhere in the installation may raise the voltage of earthed equipment downstream of the RCD to dangerous levels, a RCD does not remove the requirements for basic and fault protection along with the requirement to mitigate touch voltages.


We are not even supposed to to test the RCD without doing an earth fault loop impedance test first to ensure that the circuit is adequately earthed.


The first thing you do when you arrive on site to alter or extend a circuit is to confirm the type and adequacy of the installation earthing arrangement, then you confirm if the circuit you are going to work on is fit and healthy,  so personally I walk in and visually inspect the distributors equipment, the main earth and earthing arrangement, the consumers consumer unit or fuse board, then go to the point where I want to alter or extend the circuit and do an earth loop impedance test, then if there is a RCD protecting the circuit disconnect the circuit by testing the RCD.


That process is not perfect, you may be able to see that there is a main earth conductor installed to a suppliers TN earth terminal, but in reality there could be a high resistance termination or fault rendering it useless, but you got a good loop test result due to a parallel path such as the gas pipe, that’s life.


 Andy Betteridge