TNCS 6mm main earth - EICR

You can  either select the CSA of the earthing conductors in accordance with Table 54.7 of BS 7671 ( Regulation 543.1.4) or calculated the CSA using the adiabatic equation (Regulation 543.1.3). Selecting the CSA from Table 54.7 is a rule of thumb so will probably be larger than calculating the CSA. A common error for on EICRs is to view the CSA and report it as a non-compliance as it does not meet the requirements of 54.7 without carrying out the calculation which will often prove it to be satisfactory.


In addition as this situation is reported to be TN-C-S then if it is the PME flavor of TN-C-S? the minimum CSA has to comply with Table 54.8, see Regulation 542.3.1.  


So I am thinking if the earthing conductor is 6mm then it is a non-compliance as the minimum CSA has to be 10mm. So if this is an EICR? It needs to be reported as a non-compliance and coded. No thermal damage evident and been in service for many years C3 otherwise a C2 or if all the insulation is melted off a C1.

You can  either select the CSA of the earthing conductors in accordance with Table 54.7 of BS 7671 ( Regulation 543.1.4) or calculated the CSA using the adiabatic equation (Regulation 543.1.3). Selecting the CSA from Table 54.7 is a rule of thumb so will probably be larger than calculating the CSA. A common error for on EICRs is to view the CSA and report it as a non-compliance as it does not meet the requirements of 54.7 without carrying out the calculation which will often prove it to be satisfactory.


In addition as this situation is reported to be TN-C-S then if it is the PME flavor of TN-C-S? the minimum CSA has to comply with Table 54.8, see Regulation 542.3.1.  


So I am thinking if the earthing conductor is 6mm then it is a non-compliance as the minimum CSA has to be 10mm. So if this is an EICR? It needs to be reported as a non-compliance and coded. No thermal damage evident and been in service for many years C3 otherwise a C2 or if all the insulation is melted off a C1.