Submersible sludge pumps destined for pumping wastewater, faeces and non-treated sludge with total proportion of sludge dry residues max.14 percent by weight containing abrasion-proof fragmented and short-fibre materials. Pumps are advantageous to waste water treatment plants, pumping from overground and underground resources (rivers, ponds, pools, cellars, water wells, etc.). They were designed for versatile applications by reason of sufficient capacity, weight and manufacture qualities. This pump is provided with a float switch for an automatic operation – pump switching on / off with a change in a pumped liquid level, on request it is possible to supply them without a float.