Siemens NGB3B050 3-Pole Bolt-On Circuit Breaker

Siemens NGB3B050 is a 3-pole bolt-on molded-case circuit breaker (MCCB) rated 50 A for 600Y/347 VAC three-phase service, designed for panelboard installations in commercial and light-industrial electrical distributions. It belongs to the NGB low-voltage family and uses a thermal-magnetic trip unit to provide overload and short-circuit protection, with UL489 listing for use in panelboards. The breaker offers interrupt ratings of 14 kA at 600Y/347V and 65 kA at 480Y/277V, enabling safe interruption of fault currents across the applicable voltage ranges. Bolt-on mounting ensures secure attachment to compatible Siemens panels, and the 3-pole configuration protects all three phases of the circuit. Typical applications include protecting three-phase loads such as motors, pumps, conveyors, and compressors in systems that operate at 347/600 V, as commonly found in commercial and light-industrial installations.