400A Switchboards — 3 Phase 4 Wire 240/120V

For a 400A panel, NEC typically requires 1000 kcmil copper or 1250 kcmil aluminum conductors per phase for a single-conductor installation at 75°C insulation rating. In practice, contractors often use parallel sets of smaller conductors for easier handling. Always consult your local AHJ and utility requirements, and verify conductor sizing with a licensed electrical engineer for your specific application.

Yes. All DEI Power switchboards are UL 891 certified and UL listed, ensuring they meet rigorous safety and performance standards. Each unit is built with genuine Siemens components as a Siemens Approved OEM manufacturer, providing full code compliance and dependable performance for commercial, industrial, and utility installations.

DEI Power's 400A switchboards are available in NEMA 1 enclosures for indoor installations and NEMA 3R enclosures for outdoor or weather-exposed environments. Both options provide heavy-duty construction for long service life and maintain the same UL 891 certification and Siemens component quality.

DEI Power's 400A switchboards support multiple voltage configurations including 120/240V, 240V, 208Y/120V, 240/120V, 480V, 480Y/277V, and 415/240V. This flexibility allows the same platform to serve a wide range of commercial, industrial, and utility applications with a single product line.

Yes. All switchboards and switchgear from DEI Power meet UBC, CBC, and IBC requirements for all seismic zones. Additionally, products carry EUSERC approval, making them suitable for utility-grade installations across seismically active regions throughout the United States.

Most standard orders ship within 1 business day from DEI Power's Ontario, California facility, with delivery in 3–5 business days. In rare cases, up to 5 business days may be required for fulfillment. Free shipping is included on all orders nationwide, and each unit comes with a 1-year warranty.