Model # 5599 48kW 4.2L
SN = 5223743
Start up = 2/2009
Diagnostic Manual = 0H0983
We have a subject I wanted to bounce off the group for opinions or experience.
Customer called to say he lost power when he happened to be downstairs. Saw a flash and brief smoke in the transfer switch area and had no power. Found the generator was not running. He put it in Manual and it then started and provided power. Later he switched to Auto and continued to provide power to the home. Utility was restored and transferred back to utility and shut down appropriately. So we know the generator ran long enough to initially transfer then generator stalled.
We arrived to find fluctuating voltage between 240v -290v phase to phase. Frequency holding steady at 60hz. We adjusted the AVR to keep it between 200v-240v phase to phase. However we of course cannot leave it that way. The arc and smoke came from an electrical panel surge protector that was destroyed. Most probably because of the high voltage output from the generator.
We found PIB08-14-S (attached) on how to perform a start up on the AVR.
Steps we have taken:
Rotor tests good; Stator tests good; Brushes, wiring and all connections test good; Physically examine both brush assemblies; Clean and shine slip rings; Perform start up on AVR as per PIB
AVR notes: The PIB and the diagnostic manual both state that during VR adjustment if the red LED (voltage regulator on) is flashing then adjust the Gain pot. ccw until the flashing stops. In two different steps - loaded and unloaded it states that the three lights should be solid and if the red LED is flashing then adjust the Gain until it stops flashing. When running the unit and adjusting the VR at no time did the red LED flash - even if we tried to make it flash by adjusting the gain and/or the freq. to their limits, all lights stayed solid with the machine running loaded or unloaded.
On a test run Voltage and Frequency initially hold steady. Upon generator warming up voltage begins to fluctuate, and frequency holds steady. Two tests unloaded and loaded with same result.
We have not had one operate this way. Before we condemn an expensive AVR I just wanted to get some feedback.