Manual for Induction Motors and Generators
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3BFP 000 050 R0101 REV E
7.5.4 Bearing insulation and bearing insulation resistance check .................... 75
7.5.4.1 Procedure .......................................................................... 75
7.5.4.2 Cleanliness of bearing insulation...................................... 77
7.6 Maintenance of stator and rotor windings ................................................................ 78
7.6.1 Particular safety instructions for winding maintenance........................... 78
7.6.2 The timing of the maintenance ................................................................ 79
7.6.3 The correct operating temperature........................................................... 79
7.6.4 Insulation resistance test.......................................................................... 79
7.6.4.1 Conversion of measured insulation resistance values....... 80
7.6.4.2 General considerations...................................................... 81
7.6.4.3 Minimum values for insulation resistance ........................ 81
7.6.4.4 Stator winding insulation resistance measurement ........... 82
7.6.4.5 Rotor winding insulation resistance measurement............ 83
7.6.5 Insulation resistance measurement for auxiliaries................................... 84
7.6.6 The polarization index............................................................................. 84
7.6.7 Other maintenance operations ................................................................. 85
7.7 Maintenance of slip rings and brush gear................................................................. 85
7.7.1 Care of slip rings...................................................................................... 85
7.7.1.1 Standstill period ................................................................ 85
7.7.1.2 Wear.................................................................................. 85
7.7.2 Care of brush gear.................................................................................... 85
7.7.2.1 Brush pressure................................................................... 86
7.8 Maintenance of cooling units.................................................................................... 86
7.8.1 Maintenance instructions for machines with open air cooling................ 86
7.8.1.1 Cleaning of filters.............................................................. 87
7.8.2 Maintenance instructions for air-to-water heat exchangers..................... 87
7.8.3 Maintenance instructions for air-to-air heat exchangers.......................... 87
7.8.3.1 Air circulation ................................................................... 87
7.8.3.2 Cleaning ............................................................................ 88
7.8.4 Maintenance of external blower motors .................................................. 88
7.9 Repairs, disassembly and assembly.......................................................................... 89
Chapter 8 - Trouble Shooting
8.1 Trouble shooting....................................................................................................... 90
8.1.1 Mechanical performance.......................................................................... 91
8.1.2 Lubrication system and bearings ............................................................. 92
8.1.2.1 Lubrication system and rolling bearings........................... 92
8.1.2.2 Lubrication system and sleeve bearings............................ 93
8.1.3 Thermal performance............................................................................... 95
8.1.3.1 Thermal performance, open air cooling system................ 95
8.1.3.2 Thermal performance, air-to-air cooling system............... 96
8.1.3.3 Thermal performance, air-to-water cooling system.......... 97
8.1.3.4 Thermal performance, rib cooled...................................... 98
8.2 Oil leakage of sleeve bearings.................................................................................. 99
8.2.1 Oil ............................................................................................................ 99
8.2.2 Sleeve bearings...................................................................................... 100
8.2.3 Bearing verification ............................................................................... 100
8.2.4 Oil container and piping ........................................................................ 101
8.2.5 Oil container and piping verification..................................................... 101
8.2.6 Use......................................................................................................... 102