Starter - Exciter circuits for a 12kw BDC Generator 1

[Murphy99]

I have the honour to recomission this "old gentleman" a Petter Waushaka Single Phase 110/220Volt 60hz, 63 amps.
Inspected the brushes, commutator and sliprings - good shape. Blew the dust off. Hooked up 24volt battery (correct Polarity)and loadbank. Pressed the START. The Generator cranks the engine. It starts. Ramps to 1800. Select Load ON. Voltage goes to 243. Current 3 amps. Increase load to 10 amps. Freq drops to 58. Fiddle with governor linkage. 60 Hz. 240V. Increase load to 20 amps. Governor does not respond. Freq drops to 55.Fiddled the linkage again. Volts drop to 10.
shutdown. Restarted several times nothing more than 10V. Nameplate has Excitation volts 60 VDC. I guess this is a "wound rotor". Acts as a DC Motor to start. By magic ...some RPM stops cranking and reconfigures to alternator (Select ON OFF ON). Under the exciter coils ther is a DIODE Bridge (to get the 60VDC??)and 2 wire wound resisters.
Need a schematic to identify a voltae regulator to begin troubleshooting the DC. Still have 10VAC, little current independent of load.
Anybody know of a web accessible schematic to begin troubleshooting?
TIA

 

[jbartos]

Suggestion: Search for service firms that service generators, e.g.

http://www.generator.com/ServiceA.htm

http://www.electricleague.net/g listing.htm

etc. for more info

 

[Murphy99]

Thanks for the post. Got lucky. Rectifying Diodes and wire wound resistor was good. Hated to snip wire ties (without schematic)but unable to trace where I was loosing my excitation power source. Turned out to be a broken wire on an excitation coil. Should have known as it was all painted in area with new varnish. Kind of proud of my test stand. Can send you a pic (off forum) if you are interested. Better to be lucky than smart.