Electric Reference

note: This is a live test

Ze can be remembered as Z external (Ze)

1. Safley isolate supply
2. Disconnet the earthing conductor
3. Set test metre to loop test (20 ohms)
4. One test probe shall be placed on the incoming Line conductors
5. The other test probe shall be connected to the disconnected main earthing conductor (3 lead test shall be refered to the manufactors manual, in some cases the 2 leads (green & black) shall be connected to each other
6. Test and record result
7. Reconnect the earthing conductor
(Zs= Ze + (R1+R2) )