what is meant by - or + in first table
Topic on Talk:Selection criteria for the TT, TN and IT systems
From Electrical Installation Guide
Hi @Vpvignesh001, this table is comparing the different earthing systems according to a number of criteria/needs. The "-" (and "--") mean that the related earthing system (column) is NOT well adapted for that criteria/need (line). The + (or ++) means that the related earthing system (column) is performing well for that criteria/need (line). And sorry for the late reply, I missed your question.
