hi, i am doing a private course at home [EAL level 2. domestic installations] everything seems to be going OK and i have my exams next month.. please can you help with a little dilema i have regarding testing. i have bought a megger MFT 1553 and have been doing tests around the house. On page 92 in the ON SITE GUIDE is table 2D showing the maximum earth fault loop impedance for all BS 60898 MCB's. i am looking at the type B MCB's on the table and it states for a 6A lighting circuit, the maximum loop impedance is 6.40 ohms.
for the 32A ring main it is 1.20 ohms, for a 40A shower circuit it is 0.96 ohms and so on.... what i need to know is where do i test to get the reading?
for the lighting cicuit....where on the circuits do i apply the test leads?
for the ring main......... where on the cicuit do i test?
for the shower............where do i test?
i would really appreciate your help as my tutor is on holiday