Abstract: An Iso-Parallel UPS system may combine the system redundancy, isolation and fault-limiting properties of isolated-redundant systems, with the ability to spread system load evenly across all modules like paralleled systems. This system may have the following features: (1) the critical load can be divided into two or more portions, and each portion may be individually fault tolerant, i.e., any electrical fault on a critical load will affect only the load in that portion—other portions of the critical load can remain connected and operating; (2) the critical load can be shared among all modules within the configuration, and all modules may be equally loaded, or nearly equally loaded—there is no designated redundant unit; and (3) any module can be taken out for maintenance without impacting the critical load.