Any advice where I can source (BS's/Standards etc) the earth value of a sub-station. My thoughts are that it should be less than 1 ohm, but getting conflicting reports that it can be up to 5 ohms???
Also being advised that a common earth can be used, being linked between sub-stations. Surely...
QCE - Using a Megger. Testing cabling for a 240V supply (1.5mmm2) and Control Cabling (twisted pair). Will both require to be tested at different setting depending upon the rating of the cable as mentioned by Ralph.
I am specifying the testing of installed cabling, and once this is complete it will obviously have to be tested. How do I determine what setting I should select on my megger i.e. 250V, 500V, 1000V ???
