5.4　Generator Rotor

5.4.1　Before installation the generator rotor shall comply with the following provisions:

1　Box of generator rotor shall be opened inside the building；the rotor taken out of box shall be placed on the dedicated support provided by manufacturer.

2　For lifting of rotor，the retaining ring，journal，fan and collector ring must not be applied with load.

3　Provisions against dust and collision shall be made at bearing journal，sealing pad journal，collector ring and ventilation holes，and the rotor shall be protected in enclosed state.

5.4.2　The rotor of a air-cooled generator shall be subject to the following inspection and comply with specification before installation:

1　Check in cooperation with electrical personnel，to confirm that the rotor parts and slot wedges are not loose，and the ventilation channels are clean and well through.

2　The balance weight shall be securely fixed and locked；the nuts on rotor shall be tightened with provision against loosening；the shrunk-on ring shall be free of crack or displacement in visual check.

3　The journal shall be smooth and free of oily dirt，paint，rust，pit or mechanical damage，and the ellipticity and non-cylindricity of journal shall be less than 0.03mm.

4　The couplings shall be checked as per 4.6.3 hereof and shall comply with specification，and the measurement shall be done in advance if the coupling flange ending run out cannot be measured after the rotor is set to place.

5　The impeller of centrifugal fan shall be firmly fitted on the shaft，and blades shall be free of looseness，cracked weld or other mechanical damage.

6　Axial flow fans shall be checked as per requirements in 5.5.3.

7　Inspection of center hole on generator rotor shall be performed according to 4.6.2.

5.4.3　Inspection of the rotor of a hydrogen-cooled generator shall also comply with the following provisions in addition to that in 5.4.2:

1　The journal at the ring shaft sealing part shall be smooth and free of oily dirt，rust，pitting or other mechanical damage.

2　Rotor ventilation hole plugs shall be all removed and verified by inspection personnel.

5.4.4　The rotor of a hydrogen-cooled generator shall be subject to the following inspection and comply with specification before leakage test:

1　The sealing surfaces of center hole blinds on both ends of rotor shall be flat and free of burr or radial groove；the blind shall be tightly installed and locked.

2　For the air duct for testing，a hole can be made on the temporary blind at the exciter end，and after completion of test，the original blind can be put back and sealed.

3　Oil-resistant rubber sheet should be used as packing for center hole sealing surface.

4　The rotor leakage test shall be performed separately，with the emphasis on checking the sealing condition of conducting screws under the slip rings and the center hole blind，the test pressure and permissible leak rate shall comply with manufacturer requirements，or in accordance with Appendix G if there is no requirement from the manufacturer.

5.4.5　Inspection of the rotor of a dual internal water cooled generator shall also comply with the following provisions in addition to that in 5.4.2:

1　The rotor inlet port blind shall be in good sealing，the water outlet plugs shall be complete and tightened，if any of them has fallen off or be removed temporarily，it shall be put on again after confirming there is no sundries inside the port.

2　A separate hydrostatic test shall be performed for rotor and the test shall comply with the provision in 5.1.6，the test pressure shall comply with manufacturer requirements and there shall be no leakage after it is maintained for 8h，and it shall also be confirmed that the water outflow from each coil is about the same and there is no blocking inside.

5.4.6　Inspection of the rotor of a water hydrogen-cooled generator shall be in accordance with relevant provisions in 5.4.3 for hydrogen-cooled rotor.

5.4.7　Generator rotor installation shall be performed after completion of all work for mechanical，electrical and I&C，following a joint final inspection of stator and rotor by relevant personnel and after confirmation and signature.

5.4.8　Rotor shall be installed using the method recommended by manufacturer and the special tools provided by manufacturer；before the work，a work plan shall be prepared and approved；for self-made tools，calculation and check shall be made.

5.4.9　Installation of rotor into the generator shall comply with the following provisions:

1　The shrunk-on ring，fan，sliding ring，journal，air baffle，oil baffle and lead-out on the rotor，the shaft sealing part on a hydrogen-cooled rotor and the coupling and water pipe connection shall collar at the excitation end of a dual internal water cooled rotor must not be applied with load during lifting and support，and must not be collided during installation.

2　The tying of wire ropes must not damage rotor surface，wire ropes shall be wrapped with soft materials，or flexible slings shall be used in lifting.

3　Slings shall be firmly tied on the rotor and be wrapped on rotor and locked；hard wooden strips or aluminum sheets shall be put on the rotor surface.

4　During lifting and when the rotor proper is used to support itself，the large teeth shall be in vertical direction，as shown in Fig.5.4.9；for a hydrogen-cooled rotor，the padding strips and sheets shall be distributed over small teeth between slot wedges，so that no force is exerted onto slot wedges.

5　For a rotor with axial flow fan blade top diameter greater than retaining ring diameter，before inserting it into the stator，the blades shall be removed to prevent damage；the blades shall be marked for replacing at original positions.

6　Before rotor installation，the front bearing cavity and water outlet support cavity shall be carefully checked for concentricity with stator，the inner diameter of all cavities through which the rotor coupling will pass through shall be greater than the coupling outer diameter，to ensure smooth passing of rotor coupling.

7　When the rear bearing pedestals is suspended on rotor for simultaneous locating，soft packing shall be put between journal and upper bush，so that there is some tightening force to prevent play of bearing pedestals.

8　When the rotor is installed with special tools such as sliding block or trolley，a whole piece of soft gasket shall be but beneath the arc steel sheet，to prevent damage of core when the arc steel sheet is drawn out；during the whole process of rotor insertion，rubber gasket shall be placed at coils on both ends of stator for protection.

9　The rotor shall be kept horizontal when lifted，and shall be inserted in a slow and steady manner，preventing its swinging；the rotor and wire rope must not scratch any part or insulation of the stator.

10　During rotor insertion，if the rotor is to be supported temporarily to shift slings，the load shall be carried by the short shaft or coupling，and the provisions in items 1 and 4 hereof shall be followed if the load should be carried by the rotor proper.

11　In rotor insertion for a generator of end cover bearing type，all work starting from lifting to fitting of end covers shall be done in a continuous manner without interruption.

5.4.10　The centering for generator rotor and connection of couplings shall be done according to relevant provisions in 4.6 hereof.

5.4.11　The rotor of a water-cooled generator shall be turned when the water inlet sleeve has not been fitted with packing.