Siemens 5SX21 Molded Case Circuit Breaker MCCB

Siemens 5SX21 Molded Case Circuit Breaker MCCB is a compact, single-pole overcurrent protector designed for 277 V AC circuits; rated at 10 A, it belongs to Siemens' 5SX family of molded-case breakers and uses a C-curve trip characteristic for general‑purpose protection. Built as a molded‑case device, it provides isolation and arc energy containment while fitting in standard MCCB panelboards or control enclosures that specify the 5SX series. The combination of 1‑pole construction, 277 VAC rating, and a C‑curve profile makes it suitable for protecting branch circuits in commercial and light industrial electrical installations where a lightweight, easily replaceable protective device is required. This model supports quick replacement in compatible Siemens distribution panels and coordinates with other Siemens protection devices in the same series.