standards / manuals / guidelines for small hydro development - AHEC

• Any possible inbalance of runner (due to inertia and friction between thesupporting parts of balancing device) is determined after runner has been broughtinto equilibrium. This is done by placing weights at six to eight points of the bandcircumference which cause the runner to assume equal inclinations. The magnitudeof the residual imbalance is equal to half of max and min weights needed for this.The weight for this imbalance should be placed where the maximum weight isplaced.• The balance weight should be reliably fixed on the runner in such a way that it isprotected from the action of flow. Best location for this is on the top of runnerbeneath protective casing. The weight must be recalculated since the radius oflocation has been changed.• Balancing must again be checked after weights have been fixed.• Balancing is checked if minimum weight placed successively at two diametricallyopposite points tilt the runner by equal angle.4.5.4 Checking Concentricity of Kaplan RunnerFig 3: Checking concentricity of peripheral edges of runner blades;1) Plumb line; 2) boom; 3) cable; 4) frame; 5) rollers [Goncharov]It is advisable to check the concentricity of the peripheral edges of the blades aftertheir assembly in service bay. This is done with a special device (Fig. 3) mounted at the topof the servomotor piston rod. The check is performed by measuring the clearance between aplumb line and the peripheral edges of the blades.AHEC/MNRE/SHP Standards/ E&M Works – Guidelines for Operation and Maintenance of Small Hydropower Station 58