IEC 63132-2:2020 Guidance for installation procedures and tolerances of hydroelectric machines – Part 2: Vertical generators (IEC 63132-2:2020)

IEC 63132-2:2020 Guidance for installation procedures and tolerances of hydroelectric machines – Part 2: Vertical generators (IEC 63132-2:2020). 6 Steps 6.1 Step 1 : Turbine shaft free See the relevant turbine part of this document. 6.2 Step 2: Generator foundation check a) Objective of work in the step – Check the foundations for the upper and/or lower brackets (if applicable) and the stator. – Check the openings for cables/bars for phase terminals and neutral point. – Check the embedded water and oil piping. b) Explanation of work – Check the foundations for the lower bracket, upper bracket and the stator. – Check the dimension of the openings. – Check the position of piping (if secondary stage concreting is used, also check). – Install the foundation bolts. – Install the sole plates. c) Recommendations The tolerances should be provided by the generator supplier. – If a one-stage concreting method is used The location in plan, elevation and/or locations of the foundation plates should be checked. – If a two-stage concreting method is used The location in plan, elevation and/or locations of the foundation bolts, embedded parts and block-outs should be checked. d) Additional information There are two different methods for embedding the sole plates; one-stage concreting or two- stage concreting method. Care shall be taken when placing concrete to avoid moving the generator foundations. If the two-stage concreting method is used, the entire surface of the block-out for the lower bracket and stator bases should be prepared to ensure proper bonding between secondary and primary concrete. There are many different generator configurations. See IEC 60034-7 for a description of the possibilities. The various configurations may or may not have a lower or an upper bracket. 6.3 Step 3-1: Lower bracket assembly a) Objective of work in the step – Assemble the lower bracket. b) Explanation of work – Attach the arms to the hub, as per the design (i.e. welding, bolting). – This task is generally carried out outside of the pit. c) Recommendations The tolerances should be provided by the generator supplier, if required. If the lower bracket is assembled by welding, non-destructive tests (NDT) according to the inspection and test plan ( ) may be required. d) Additional information The generator supplier should take precautions to limit the distortion by welding in order to be able to connect to the embedded parts. The lower bracket, upper bracket, rotor and...