When two or more devices are connected to a common ground through different paths, a ground loop occurs. Currents flow through these multiple paths and develop voltages which can cause damage, noise or 50Hz/60Hz hum in audio or video equipment. To prevent ground loops, all signal grounds need to go to one common point and when two grounding points cannot be avoided, one side must isolate the signal and grounds from the other.

Pri pripojení k zemniacemu bodu prostredníctvom pospájania jednotlivých zemnených častí (slučiek z vodičov), nie zemnením do jedného bodu vzniká riziko rušenia.