This is known as interference and can be hazardous, inefficient, and a nuisance in many electrical systems. However, if the ground wire has significant resistance and current, the voltage of the second circuit will be slightly lower than the first, causing a voltage difference that makes the ground wire no longer have a ground potential. Ideally, all circuits in a ground loop circuit have the same voltage potential. A ground loop circuit is one in which two or more circuits are connected to the same ground wire. A ground loop isolator prevents interference in a ground loop circuit.
