One of our 45 kW Ohnos fired right up today but isn’t outputting any power. Checked both the main 100amp breaker and the field breaker. Any suggestion? 2005 vintage MCGCA
F'ing OhNo's. If all AVR, there may be an exciter lead with a bad connection. Some OhNo AVRs will not excite the field if "it thinks" there is a fault. Slow to come to speed, or not at speed as an example. Relays? One may fail on the exciters. I remember one OhNo that had an exciter fuse. Some where, some place, for some reason, the exciter is not getting excited.. After my second wife, I under stand this... Oh, Field breaker. OhNo uses the cheapest vendor on the pop-out fault breaker. Short this in your trials. Usually 12Vdc to the exciter windings, can you get a volt meter on that lead. I am assuming you have a later model brush-less armature,,,if not you may just have a worn or stuck exciter brush. Are you deployed?
I haven’t had a chance to look at it today. I have the operator and parts manual but nothing beyond “check the field breaker” we re in miami so my gen guy is coming tomorrow. I m pretty sure we have a spare regulator on board but I ll let him handle it. He s super helpful and deserves to make a buck
It was indeed the voltage regulator. I had a spare so it was fixed quickly by my tech and I ve told him to get me another spare
And of course Ohno hides the regulator behind TWO panels each held with a dozen screws or bolts. And the regulator is the size of the hole it s hiding in making it a pita to extract and transfer all the connections.
But wait there is more…. That spare regulator I had while looking brand new may have been used and defective. It worked far a few hours and failed. I suspect it had been removed and kept but not marked had used/failed. I Replaced with a brand new one. And got another new one as spare.
We ve out about 100 hours on it in the last couple of weeks. I think it was an old defective VR which someone just left on board