Testing of the Pole Face Winding crimpings Measurements carried out on the 100 PS main units before start up of the PS machine in 2007

The crimpings of the Pole Face Windings (PFW), used to connect the rectangular copper conductor of the main windings with its supply cable, could have defects due to the manufacture process. They could lead to an extensive high electrical resistance. To locate these defects, the PFW are powered with 80 Ampere DC and the voltage drop over the electrical resistances of the crimping is measured. The measurements are done between the PFW current leads and the corresponding pick-up. By subtracting the resistance of the supply cable and the interconnection cable the crimping resistance is calculated. During the long shutdown 2005 and the annual shutdown 2006/2007 a total of 34 main units, and their PFWs, have been refurbished [1]. The refurbished main units are equipped with new PFW. On this PFW the crimping technique was improved and the defect of high crimping contact resistance should not appear. Nevertheless to have complete picture of the situation the 34 refurbished main units and the 66 none refurbished units were measured.