Safety Upgrades in Domestic Dwellings. Pluggable Off-Line UPSs of Low Quality and Backfeed Hazards

International policies incentive the reduction of energy consumptions in domestic dwellings and the use of energy from renewable sources, but do not sufficiently support their safety. Many domestic dwellings in many countries operate with the supplying neutral grounded (T) and with all the exposed conductive parts isolated (I) that is with a “TI-system.” This article deals with a concise presentation of these unclassified types of grounding systems and, then, with the backfeed hazard originated by pluggable off-line UPSs very commons in homes of stressed electrical grids. Against frequent blackouts, the users install battery powered automatic switchover type standby off line UPS. UPSs of low quality are unsafe and must be upgraded. Cases of back feed have been noted into utility supply lines from these UPSs and linemen doing maintenance by switching off supply receiving fatal shocks. This article examines the reasons for such back feed and gives few methods to eliminate fatal and often unforeseen back feed. It briefly discusses the needs of upgrading TI-system to TT-system, basic for the safety protection against touch voltages in domestic dwellings. It concludes expecting in a next time the promotion of the global grounding system as constitution of a public “grounding service” organized and managed similarly to the water, gas, energy, telephone, or internet services.