Electrical installation & energy efficiency

Hemant Arora said:

BS 7671 Table 54G indicates Earth cable sizing for Power cable size.

If the Electrical Sub Panel is far away & local earth electrodes (Eart Pit) is provided, is it medatory to run earth continuty conductor with the cable feeding to Sub Panel

Dear ;

To decide if the PE cable should be run to a far Sub-Panel or not, we should know the used " Earthing System " for the project. For exp. in " TT system " it shouldn't be, because in this sytem we can use 2 or more different earth electrodes, but in " TN-C  &  TN-S " it should be, because we can't use more than one earth electrode.

By the way be carful if you are using " TT " that means at least 2 different earth electrods, these 2 different earth electrods shouldn't be connected, because when we connect them the earthing system will " TN ".