Siemens NGB3B100 Three-Phase Molded Case Circuit Breaker

Siemens NGB3B100B is a three‑phase, 100 A molded‑case circuit breaker from Siemens’ NGB/G‑frame for low‑voltage panelboard installations. It features a thermal‑magnetic trip that provides both long‑time and instantaneous protection, and is rated 600Y/347 VAC (600 V line‑to‑line, 347 V line‑to‑neutral). The unit carries short‑circuit interrupting ratings of 14 kAIC at 600Y/347V and 25 kAIC at 480Y/277V, making it suitable for typical three‑phase feeders in commercial or light industrial panels. This NGB3B100B is UL489‑listed and designed for panelboard mounting within Siemens’ G‑frame MCCB family, reflecting common form factors and accessory compatibility. Optional shunt‑trip accessories are available for this family, enabling remote tripping in protection schemes, along with other add‑ons such as auxiliary switches or alarm switches to tailor the device to specific protection schemes. Designed for straightforward replacement in existing Siemens panelboards, the NGB3B100B uses the G-frame form factor and standard mounting footprint to simplify integration in three‑phase distribution systems in many commercial installations.