The Grundfos AP50 pumps designed to pass solids of up 50mm, if you need to deal with solids that are larger take a look of the rest of the AP range. Grundfos AP pumps are designed for more demanding wastewater tasks, like groundwater lowering and black water work. The AP range is renowned for its reliable performance and low maintenance level. They feature a stainless steel construction for waste-water and sewage applications.
Codes ending in "1" are single phase, "3" are three phase. Single phase "A1" units are automatic, three phase "A3" units are automatic and supplied with starter where as normal three phase units are not.