Circulating current occurs only if there is more than one generator operating at the same time. If you operate a single generator, there is no where for the current to circulate out of the generator. As a result, the issue of circulating currents is not relevant in setting up a single generator system. Whenever two or more generators are operating in synchronization, however, there exists the possibility of circulating current.
Circulating Currents Travel a Certain Particular Path
There is a particular path by which circulating currents can travel between generators that are operating as part of a group. In general, circulating currents leave the line leads of the first generator, move through the parallel bus of the second generator and come back into the second generator. A circulating current will never enter a generator through the load side of the generator, because there is too much existing current, or electrical flow, through the load side as a result of the generator output. Just like with the flow of water, circulating currents will move in the path of least resistance.
Circulating Currents Can Travel Differently Through Many Generators
If there is more than one generator that has been set up, the circulating current does not travel the certain particular path that it must follow with only two circuits, but may travel through a variety of paths. This can cause problems for electrical engineers and site managers determining where these additional amps and current are coming from. This can be the cause of a dangerous condition.
Circulating CurrentsCause a Variety of Problems for Electrical Circuits
Circulating currents can cause wires or generator parts to overheat because they are not designed for the excess current flow created by these rogue currents. Circulating currents can also cause breakers to trip or fuses to blow; this can lead to operational down time as the circulating current overpowers the circuit in which it has traveled.