Bs7671 (16Th Edition Iee Wiring Regulations) Requirements; Other Methods; Fig.15 Test Spike Positions For Bs7671 - Megger DET5/4R Guia Del Usuario

MEASURING TECHNIQUES Testing Earth Electrodes
BS7671 (16TH EDITION WIRING REGULATIONS)
REQUIREMENTS
Regulation 713-11 of BS7671 specifies that the
resistance of earth electrodes must be measured. The
accompanying Guidance Notes describe a method of
test that is very similar to the Fall-of-Potential method.
If the maximum deviation from the average of the three
readings is better than 5% then the average can be
taken as the earth electrode resistance. If the deviation
exceeds 5% then the current spike should be moved
further away from the electrodes and the tests
repeated.
E
6m 6m
Fig.15 Test spike positions for BS7671 testing
22
P
C

Other Methods

There are other methods of earth electrode testing
among which are the Four Potential, Intersecting Curves
and Star Delta methods. Megger Limited have produced
a book entitled 'A Simple Guide to Earth Testing' (Part
Number 6171-230) which explains all these test
methods and gives other helpful information about
earth testing. It is available from the instrument
manufacturer or one of their approved distributors.