Rotor Test
NOTE:
Install NEW bearing at slip ring end whenever generator is reassembled. When disassembling generator, carefully note locations of insulated and uninsulated screws.
- Scribe end frames to facilitate reassembly. Remove through-bolts and separate end frames.
- Using ohmmeter, measure coil resistance between slip rings. See Fig 1. Coil resistance should be 1.7-2.1 ohms at 70°F (21°C). If coil resistance is not as specified, replace rotor.
- Using ohmmeter, check for grounds between either slip ring and rotor pole piece. See Fig 1. Ohmmeter should indicate infinite resistance. If reading is not infinity, replace rotor.
- Resistance readings will vary slightly with winding temperature changes. If generator does not supply rated output and rotor is okay, rectifier bridge, stator or regulator is faulty.
- To reassemble generator, reverse disassembly procedure. Retain brushes with brush retaining pin during reassembly. See Fig 2. Remove retaining pin after tightening through-bolts.