400mm Submersible Sewage Pumps for Metropolis-Scale Stations

Seven variants, and unlike the 300mm and 350mm sizes above, every one of them runs at 980 rpm regardless of head or power. At 400mm the impeller diameter is already large enough that a single 6-pole motor class covers the whole practical range from 7.5m to 32m head without dropping to 8-pole at the low end, which is one less variable to weigh when comparing options at this size.

All seven run at 980 rpm. The 1500 m³/h/10m/75kW variant sits at the efficiency peak of the table at 86%, in the middle of the range rather than at either extreme; that’s a reasonable pattern, since the very-low-head and very-high-head variants both push the same basic impeller geometry away from its best-efficiency point, just in opposite directions. At the top end, the 250kW unit is a different scale of project altogether: direct-on-line starting isn’t realistic, a specialized installation crew and dedicated heavy-duty lifting gear are baseline requirements, and the 670×1730×2850mm footprint deserves checking against pit and crane clearance well before the pump arrives on site.