A three-phase service can still have many 120V single-phase branch circuits, so real demand is rarely divided perfectly across all three phases. SRNE specifies 150% single-phase unbalanced-load support for this HESP range, giving the 3 phase hybrid inverter more tolerance when one phase temporarily carries heavier lighting, receptacle or equipment demand. This does not eliminate the need to balance the panel where practical. It gives the system additional operating margin for the uneven load patterns that naturally occur in mixed-use buildings.
