How many outputs does a 400A column head unit have

A 400A column head unit typically has 42 outputs (pole spaces) for branch circuits.A 400A column head unit, such as a main lug only (MLO) panelboard, is designed to distribute three-phase 208Y/120V AC power to multiple branch circuits. The number of outputs is determined by the number of pole spaces available for breakers, which in standard 400A units is 42 pole spaces . Each pole space can accommodate a single-pole or multi-pole breaker depending on the circuit requirements.Key DetailsMain Lug vs Main Breaker: A main lug only (MLO) panel does not include overcurrent protection at the main device, whereas a main breaker panel provides a primary disconnect and overcurrent protection . Both types can have the same number of branch outputs.Branch Circuit Compatibility: The 42 pole spaces allow for a combination of single-pole and double-pole breakers, enabling flexible distribution for various loads.Construction and Mounting: These units are typically NEMA-rated for indoor or outdoor use, with steel enclosures and hinged doors for safety and accessibility .Wire Capacity: Standard 400A MLO panels can accommodate large conductors, such as 600 kcmil copper or aluminum, with optional connectors supporting up to 750 kcmil . In summary, a 400A column head unit provides 42 outputs, making it suitable for medium to large electrical distribution applications, with flexibility for different breaker configurations and load requirements.