Siemens NSB NGB1B020 Miniature Circuit Breaker

Siemens NGB1B020B is a 1-pole, 20A, 347V AC miniature molded‑case circuit breaker from the NGB family, UL489 listed for panelboard and distribution use. It combines thermal and magnetic trip functions to provide reliable overcurrent protection for a single hot leg in commercial or industrial electrical panels, with long‑time and instantaneous trip action to address both overloads and short circuits. The device carries an interrupting rating of 14 kA at 347V (and 25 kA at 277V in applicable conditions), offering solid short‑circuit protection across the voltages commonly encountered in building systems. For ease of installation, the NGB1B020B is designed for panelboard mounting with bolt‑on compatibility and includes load lug terminals for convenient wiring connections. It is suitable for reverse‑feed configurations in compatible Siemens panels, aligning with standard Siemens LV/MCCB practices while maintaining compact, space‑efficient single‑pole protection. This breaker delivers a precise, reliable solution when a single 20‑amp protective device is needed in a Siemens panel—ensuring consistent protection, predictable trip behavior, and adherence to UL489 safety standards without modifying existing wiring schemes.