Siemens P1 250 Amp 208Y 120 Volt 3 Phase MLO Nema 1 Panelboard

Siemens P1 Panelboard, 250 Amp, 208Y/120V, 3-Phase, Main Lug Only (MLO) configuration, is built for indoor power distribution in commercial and light industrial settings, housed in a NEMA 1 enclosure for basic protection against dust and incidental contact. The panel supports copper or aluminum tin-plated bus and is offered in multiple space configurations, with 18, 30, 42, 54, and 66-circuit variants available in the 250 A family to fit different load needs. It is designed for 208Y/120V 3‑phase, 4‑wire systems and complies with NEC 2020 where accepted, along with NEMA PB1 and ANSI/NEMA PB1.1 requirements for standard panelboard installations. As a Main Lug Only (MLO) panel, it provides distribution without a main breaker, requiring upstream main protection or a separate disconnect. Siemens’ P1 line uses model codes such as P1C18ML250ATS, P1C30ML250ATST, P1C42ML250ATS, and P1C66ML250ATST to denote space count and ML configuration, reflecting the family’s standardized design language and labeling. This combination of 250 A capacity, 208Y/120 V operation, three-phase wiring, and MLO/NEMA 1 enclosure makes it suitable for applications like commercial electrical rooms, lighting and power distribution panels, and branch circuit organization in spaces with moderate electrical loads.