400 Amp Switchboards — 3 Phase Industrial

For a 400 amp service, the National Electrical Code (NEC) typically requires 1000 kcmil copper or 1250 kcmil aluminum conductors per phase, though actual wire sizing depends on the specific installation, conduit fill, ambient temperature, and local code requirements. Always consult a licensed electrician and your local authority having jurisdiction (AHJ) to confirm the correct wire gauge for your specific application.

DEI Power's 400 Amp switchboards are UL Listed and UL 891-certified for low-voltage switchgear, EUSERC-approved for utility service entrance applications, and manufactured as a Siemens-approved OEM. They also meet UBC, CBC, and IBC seismic zone requirements, making them suitable for installations across all seismic regions in the USA.

DEI Power offers 400 Amp switchboards in both NEMA 1 (indoor) and NEMA 3R (outdoor, weather-resistant) enclosures. NEMA 1 is suitable for protected indoor environments, while NEMA 3R provides additional protection against rain, sleet, and external ice formation, making it appropriate for outdoor or semi-exposed utility and industrial installations.

The 400 Amp switchboards support a wide range of voltage configurations including 120/240V, 240V, 208Y/120V, 240/120V, 480V, 480Y/277V, and 415/240V. This multi-voltage flexibility allows the same switchboard platform to serve single-phase and three-phase commercial, industrial, and utility applications across diverse project requirements.

Yes. Service entrance switchgear and switchboards must be built to approved utility specifications set by the serving utility. DEI Power's products are EUSERC-approved and built to meet these requirements. Because utility standards vary by region, customers are required to call and speak with a DEI Power specialist before placing an order to ensure the unit is configured to the correct utility specifications.

400 Amp 3-phase switchboards are commonly used in commercial buildings and campuses, industrial manufacturing and processing facilities, utility and infrastructure projects, data centers, and healthcare facilities. They provide the primary power distribution backbone for environments where continuous, reliable power delivery and load protection are critical operational requirements.