Siemens P1-250A-208Y-120-NEMA1 Main Breaker Panelboard

Siemens P1-250A-208Y-120-NEMA1 Main Breaker Panelboard is a P1 panel interior rated for 250 A with a 208Y/120 V, 3-phase, 4-wire supply housed in a NEMA 1 enclosure for indoor service distribution. The panel's bus is copper or tin-plated aluminum and is specified for 250 A maximum, supporting a broad range of branch-circuit configurations from 18 up to 66 single-pole circuits, depending on the interior model. For example, the 30-space variant P1C30MC250AT is rated for 208Y/120 V and comes with a main breaker configuration and a 100 kA SCCR (as documented for that interior), while larger interiors such as the 54-space P1X54MC250AT are also offered to accommodate more circuits in the same 208Y/120 V, 3-phase system. Siemens notes NEC 2020 adoption (where accepted) and compliance with NEMA PB 1 standards for P1 panelboards, reinforcing their suitability for commercial/industrial indoor power distribution. The P1 family covers a range of interior counts and configurations, all designed to deliver reliable main-breaker protection in a compact footprint, with the 208Y/120 V 3Ø4W arrangement being the common configuration for these panelboards.