standards / manuals / guidelines for small hydro development - AHEC

• Check rotor level, verticality of shaft and centering of shaft, correction of inclinationof shaft to be done at this stage itself (Alignment of generator).• Couple Exciter shaft and assemble exciters, PMG, Oil header (Kaplan) etc. carry outcentering and setting.• Couple Turbine and Generator shaft properly as per procedure with help of torquespanners. Ensure elongation of shaft bolts as per procedure.• Checking unit alignment and taking corrective action by providing shims orscrapping.• Carry out load sharing of thrust pads.• After completing assembly of machine and rotating the machine at no load checkbalancing of rotor as per procedure. Balancing of the machine by adding calculatedweight on rotor spider and at proper angle, is done.• Check vibrations of machine at no load, part load and full load, rectify defects if any.4.5.2 Checking Concentricity of Labyrinth SealsThe upper and lower labyrinth rings must be concentric with the shaft to within 10%of the gap on one side of the labyrinth seals. This is checked with a special device mountedon the shaft (Fig. 1)Fig 1: Device of checking concentricity of labyrinth-seal rings:1)Testing device; 2) support with roller; 3) indicators [Goncharov]4.5.3 Balancing of RunnerFor balancing of runner a balancing device, ‘1’, a steel plate ‘2’, a sphere ‘3’ will berequired (Fig. 2). The centre of gravity of runner must always be below centre of gravity ofsphere so that during balancing runner remains in stable position. Following steps are takento balance the runner.AHEC/MNRE/SHP Standards/ E&M Works – Guidelines for Operation and Maintenance of Small Hydropower Station 56