This document covers pump units consisting of: one single or several rotodynamic water pump(s), including where integrated in other products, and driven by a motor system, consisting of an electrical motor and either a terminal box which only enables to operate the pump unit at constant motor stator frequency and thereby (nearly) constant rotational speed, or a CDM (Complete Drive Module) which enables to operate the pump unit at variable rotational speed depending on a varying demand of flow rate and/or discharge or differential pressure. NOTE 1 A motor system which consists of an electric motor and a CDM is also called PDS (Power Drive System). NOTE 2 A CDM is also often called VSD (Variable Speed Drive). Pump units as defined above are treated as extended products in respect to their energy efficiency.