Paralleling Dissimilar Generators: Part 3 – Load Sharing Compatibility

Generator sets cannot operate in a stable fashion in parallel with other sources unless the loading on the generator set is controlled. When generator sets are operating together on an isolated bus (that is, not grid-paralleled), they are commonly provided with equipment to allow each machine to operate at the same percentage of load as the percentage of load on the total system. This is termed a “load sharing control system.” Many options are available for load sharing controls from various manufacturers, and many of these options are not compatible with each other. So, when considering the paralleling of dissimilar generator sets, or adding generator sets to an existing paralleling system, it is critical to understand how load sharing can be accomplished. Load sharing factors