standards / manuals / guidelines for small hydro development - AHEC

Sl. Rating Type GaugeNo.Shorter axis Longer axis1. Up to 5 MVA Flat, uni-directional As per manufacturer’s practice,however, not to exceed 1000 mm2. 6.3 MVA Flanged, bi-directional 1435 mm 1435 mm3. 10 MVA and Flanged, bi-directional 1676 mm 1676 mmabove(r) Inspection cover.(s) Cooling accessoriesONAN/ONAF cooling1. Radiators with shut-off valves and air release plugs.2. Fans.3. Filter valves.4. Drain and sampling device.5. Air release device.16.0 Dielectric Tests(a)220/132 kV windingi) Lighting impulse on all the line terminals (routine test)ii) Induced over-voltage with partial discharge indication (routine test)(b)33 kV windingi) Separate source AC on the all line terminal (routine test)ii) Lightning impulse on all the line terminals (routine test)17.0 AccessoriesNormal accessories are arcing horns, oil flow alarm, fans and pumps, dissolved gasmonitoring system, Temperature detectors, Lifting devices.Provision of Following Oil preservation system are preferred for generator step-uptransformer.(i)(ii)Inert gas pressure system. Positive nitrogen gas pressure is maintained in the spacebetween the top of the oil and the tank cover from a cylinder through a pressure-reducingvalve.Air-cell, constant-pressure, reservoir tank system. A system of one or more oil reservoirs,each containing an air cell arranged to prevent direct contact between the oil and the air.3-13