Maximize Performance, Versatility & Virtually Eliminate Downtime. The MS Series is a family of solid-state frequency converters with models from 62.5 to 625 kVA, standard 47 to 500 Hz (optional to 1,000Hz) with a unique master/slave configuration, which allows up to ten 62.5 kVA mainframes to be paralleled in the field. The MS Series is designed to maximize performance, versatility and virtually eliminate downtime.