5.3　Stator

5.3.1　Installation of generator stator shall comply with the following provisions:

1　Before installing the generator stator，a visual check shall be done in cooperation with electrical personnel for freedom of damage；the stator installation area shall be isolated to prevent access of irrelevant personnel.

2　People working inside the stator shall wear working clothes without button and pocket and soft working shoes without nail，all articles carried in shall be counted and checked after completion of work.

3　During storage，temporary enclosing provision shall be made to prevent dust and other sundries from entering.

5.3.2　The stator of an air-cooled generator shall be subject to the following inspection and comply with specification before installation:

1　The ventilation grooves and holes shall be checked to confirm it is clean inside.

2　The ring fire extinguishing water pipe inside the stator shall be tightly sealed，there shall be insulation between the clamp and ring water pipe，and the water spray hole on the water pipe shall be aligned to the generator end coil.

5.3.3　Before installing the stator of a hydrogen-cooled generator，the following shall be checked and conform to specification in addition to checks in 5.3.1:

1　All flange sealing surfaces on stator casing shall be flat，free of burr or radial through groove，the studs shall be tightened，and threaded holes shall not penetrate through the casing wall.

2　The end cover horizontal joint surfaces shall be in good contact，and free of gap when checked with a 0.05mm feeler gauge；the vertical joint surfaces between stator and end hood shall be flat，free of burr or radial through groove and in good contact；there shall be no gap when checked with a 0.05mm feeler gauge after 1/2 of the bolts on joint surfaces have been tightened.

3　The offset between the sealing pad horizontal split and end cover horizontal split shall be less than 0.03mm.

4　The inner wall of grooves with sealing packing on end cover shall be smooth，the dimensions of all sections shall be homogeneous and consistent，the packing holes shall be through and be aligned with groove.

5　The stator leakage test shall be performed separately，the test pressure and permissible leak rate shall comply with manufacturer requirements，or in accordance with Appendix G，at the test，the end cover blind shall have a sufficient strength，and air shall be filled and released slowly in the air pressure test.

5.3.4　For installing the stator of a dual internal water cooled generator，the following shall be checked and conform to specification in addition to checks specified in 5.3.1:

1　Stator cooling water header inlet and outlet shall be properly sealed，and in case of damage or falling off of blind，no sundries shall have entered the inside of water pipe.

2　The insulated water pipe，water pipe connector，collector pipe and sealing gasket shall be checked for correct connection according to manufacturer drawings，the insulated water pipe shall be in sound condition，and there shall be a spacing greater than 20mm between the insulated water pipe and end cover and between the insulated water pipes and they must not contact with each other.

3　The generator stator shall be subject to hydraulic test or air pressure test as per 5.1.6 and manufacturer requirements，and the water circuit connectors，insulated water pipes and internal windings shall be free of leakage.

4　Care shall be taken to prevent water and keep clean during works for the leakage testing devices inside the bottom covers at the ends of stator.

5.3.5　Before installation of the stator of a water and hydrogen-cooled generator，the relevant provisions in this section for dual internal water cooled and hydrogen-cooled stators shall be implemented；if the stator casing is in segments，the inspection of connection flanges shall be in accordance with the relevant provisions for installation of flanges at both ends of a hydrogen-cooled stator casing.

5.3.6　The shims between stator and soleplate shall comply with the following provisions in addition to those in item 1 of 5.2.2:

1　Openings shall be made on the shim at the connecting bolts，to facilitate mounting，removal and adjustment.

2　The thickness of steel adjusting shims between stator and soleplate and bearing pedestals and soleplate shall be identical；and detailed record shall be made after final adjustment.

5.3.7　The lifting and locating of generator stator shall comply with the following provisions:

1　Approved technical plan and safety provisions shall be available before lifting and locating of stator.

2　Isolation provision shall be made for stator lifting area to avoid access by irrelevant personnel.

3　Steel wire ropes shall be tied on dedicated lugs on stator casing.The fixing bolts of lugs shall be complete and tightened；without approval，it is not allowed to tie up the wire ropes at other parts of the stator casing for lifting.

4　The strength of architecture structures，lifting machinery and auxiliary lifting facilities related to lifting must be check calculated，and performance test shall be performed，to meet the lifting requirements.

5　After locating the stator soleplate，the permissible deviation of its longitudinal and transversal centerlines and elevation from design values is 1.0mm.

6　If the terminal box cannot be located after locating the generator stator，before locating the stator，the terminal box shall be lifted to the opening in advance，and its top shall be about 1m lower than the actual elevation and it shall be properly covered.

7　Before lifting the stator of an air cooled and dual internal water cooled generator，the concrete foundation air duct and metal air duct shall be cleaned as per 4.2.1；the metal air duct shall be lifted and put into the foundation frame before locating the stator.

8　During lifting，the lifting equipment and building structure shall be monitored for any anomaly，and the stator shall be kept horizontal at all times.

9　After installation and locating of stator soleplate，permanent shims on both sides of locating anchor plate shall be made，the gap on both sides shall comply with drawing requirements and a gap of 0.05mm should be provided if there is no requirement on drawing.

5.3.8　Installation of generator stator shall comply with the following provisions:

1　Adjusting shims over 3mm shall be provided between generator casing base and soleplate，and the soleplate shall be tightened with the base using linking bolts.

2　Before leveling and centering of generator，a temporary jack can be fitted at the stator lifting position for adjustment in conjunction with lifting bolts.Sufficient space shall be provided for the lifting bolt block and bottom of corresponding counter bores on soleplate，so that the soleplate can move up and down with the base in generator elevation adjustment.

3　After completion of initial alignment of generator and excitation device rotor and stator and the stator longitudinal and transversal centers and elevation comply with specification，secondary grouting shall be done between the soleplate and foundation with load supported on temporary jack and lifting bolts.

4　The mixing ratio and process of secondary grouting concrete shall be in strict accordance with manufacturer requirements，during casting，load bearing parts such as jack，lifting bolts and blocks must not be touched，a dial gauge shall be provided on the soleplate for monitoring，and the soleplate must not be moved.

5　After secondary grouting has reached the required strength，remove the linking bolts between base and soleplate，release the jack and lifting bolts，and the soleplate shall not settle when monitored with the dial gauge.

6　After the generator stator is placed on the soleplate，recheck the center of couplings of generator and turbine rotors for any change and make adjustment accordingly.

7　Lift the stator again with lifting bolts，and adjust the shims between the base on both sides and soleplate，the length of shims shall comply with the dimensional requirements of manufacturer，they shall be in a ladder arrangement longitudinal along the axial line，and the number of shims on left and right shall be symmetric and equal；after the lifting bolts are released，the axial and center positions of stator shall remain unchanged.

8　Make outer sleeves for anchor bolts（as shown in Fig.5.3.8），when the anchor bolts are tightened to the torque specified by manufacturer，a gap of 0.03mm-0.25mm shall be maintained between the nut washer and base，the stator base shall be in a free state，and the soleplate shall be linked with the foundation as a whole piece.