Square D 30021-505-51 Control Transformer

Square D 30021-505-51 is a control transformer designed to supply low-voltage power to control circuits within electrical panels and machinery. Manufactured under the Square D brand, this unit carries the part number 30021-505-51 for precise identification and maintenance. As a control transformer, it steps down incoming power to a suitable level for relays, timers, contactors, and other control devices, providing a dedicated power source that helps isolate control circuitry from main power and reduce electrical noise in control wiring. The 30021-505-51 designation identifies the exact transformer in Square D's lineup, enabling accurate replacement in Square D installations. In typical applications such as motor control centers, control panels, and equipment cabinets, it supports reliable operation of automation components that rely on a separate control-power supply. For complete electrical ratings, mounting options, and compatibility with specific Square D systems, refer to the official datasheet or product catalog.