Greetings All: I have been in the industrial electrical business for a long time. I am very familiar with motors being rewound and machined. I have been in business for myself now for about 8 months. We supply, service, install, lease and rent Emergency Standby Generators. I am also a licensed electrician in Alabama and Georgia, USA. We recieved a portable generator the other day that would not hold a "one step" load drop. It is a GB5000-2 Devilbiss portable. It has one 20A 240vac duplex recpt and one 20A 120vac duplex recpt. We disconnected these and ran straight to the stator wires for the load test. We one step it and it DIED. after restarting it we got it to produce about 15% of load regulated, anything else would drop the frequency to as low as
50Hz. We proceeded to meg the stator. When we did this smoke came from the stator. The stator has 4 wires and 2 capacitor wires. We measured with a VOM across L1 and L2=infinity, L1 to Neutral = .4 ohms, L2 to Neutral=infinity, L1 to ground wire=.2ohms, L2 to ground wire=infinity. VOM on capacitor read 49.9 and cap is rated for 50.microfarads. I am assuming that there was a slight breakdown in the winding and the generator was ok at small load then as load increased leakage to ground increased. Then we it was megged at 1000VDC it shorted completely. My question is, Is this a good assumption and if it is can we rewind this stator. iT is simply a 2pole 3600rpm stator. Or do we have to take it to a motor shop. Any help is appreciated.robert mcmahon global energies