Square D DU321 General Duty Safety Switch 30A 3P Non-Fusible 240V NEMA 1

The Square D DU321 is a reliable general duty safety switch designed for disconnecting power in residential, commercial, and light industrial applications. This non-fusible, 3-pole switch is rated for 30 amps at 240V AC, making it suitable for controlling motors, lighting, and other electrical loads where overcurrent protection is provided elsewhere in the circuit. Housed in a durable NEMA 1 enclosure, it offers indoor protection against contact with live parts and is UL listed for safety compliance. Key features include a visible blade design for easy verification of switch position, a robust handle mechanism for manual operation, and compatibility with standard wiring configurations. Advantages over similar products include Square D's reputation for quality and longevity, with a compact footprint that facilitates easy installation in tight spaces. However, as a non-fusible model, it requires separate fusing for circuit protection, which may add to overall system cost. Drawbacks include limited suitability for outdoor or harsh environments due to the NEMA 1 rating, and it may show signs of wear in used conditions. Based on image analysis, this unit appears used with minor rust on internal components, no visible damage, and intact labeling including catalog number DU321 and ratings. Typical applications include service entrance disconnects, HVAC systems, and machinery isolation. For detailed specs, refer to the official Square D datasheet (available at https://www.se.com/us/en/download/document/DU321_Datasheet.pdf). Estimated market value for a used unit is $50-100 USD, based on recent sales data from sites like eBay and industrial surplus vendors.