Reason for getting high earth fault loop impedance Ze

[Muazzam83]

While Testing Earth Fault Loop Impedance at Distribution Board it was found that the value of External Earth fault Loop impedance Ze is 45ohm and hence the value of total earth fault loop impedance Zs measured at the socket outlet is also very high. In order to confirm the reading the value of Ze is also measured at the Sub Main Distribution board feeding the DB and we got similar high values.

The value of Zs and Ze measured at different DB’s and SMDB’s found having similar values. As per standard required value of Ze shall be 0.35 ohm.

Note:

All the SMDB’s and DB’s are feeding from one LV Panel.
Type of earthing system used is TN-S.
Ground resistance of Earth Electrode connected to LV Panel is 1 Ohm.

Can any one guide to know the reason for getting such high values????