It has continued to be rainy. Really rainy. Over 100 inches so far this year rainy. There’s been a decent amount of solar generation going on, even with the overcast and rain, so when HA asked if it was okay to use the clothes dryer yesterday, I said “sure.” There was enough power to run the dryer, and enough daytime left to replace the charge lost if trends continued. Alas, trends didn’t continue, and when I got home from yoga at 5pm the sky was dark and the house batteries only had 30% charge. Not enough to get through the night.
“No problem,” thought I, “an hour or two of generator power can top us up.” By then, however, it was raining pretty hard so I had to slog through the storm out to the generator house to fire it up. As always, it started right up without hesitation. Unlike always, about 20 seconds later it shut down.
We’ve been plagued with unexplained shutdowns a few minutes after starting ever since the generator was new. I’d always just thought it was an overly sensitive carbon monoxide sensor, though the indicator light never seemed to light up. In the past, the problem has always gone away if I just start it again or, rarely, start it a third time. This time, however, it was a hard fail. The generator would fire up immediately with the push of the starting button, but never ran for more than a minute. No error codes or lights.
I quickly tired of sitting in the mud, getting rained on, with failing daylight. I decided we’d just try to white-knuckle it through the night. We shut off the water heaters, the hot tub, extra ceiling fans, the dehumidifier, and I asked HA to stop cooking. I slept poorly, worried about our power, and at about 2:15am the inverter shut down due to low battery state-of-charge.
It was light enough at 6am to do some more troubleshooting. It had also mostly stopped raining. I dragged a propane cylinder down to the generator house and tried alternative fuel, which should rule out fuel pump and filter problems and most carburetor issues. The symptoms didn’t change. I checked the exhaust system. No problems. The oil level looked good, but I moved the generator to a more level surface, checked the oil again, and added some as there was room. Still no change. I checked the air filter: it looked like new. I re-read the manual (desperate times…). Clearly this wasn’t a trivial problem.
I needed hot coffee, so I unplugged the autotransformer and plugged the inverter into the old, noisy 13 kW generator. It was due for a test running anyway, and it fired right up. I didn’t reconfigure the inverter so it was only drawing 2 kW, which kept the old beast from being too noisy at 6:30 in the morning, and power was restored to the house.
I did a bunch more troubleshooting on the new generator, but it seems pretty apparent that either the oil level sensor or the CO sensor is defective. That would also explain the strange stopping problem I’d observed earlier. I started to just bypass the sensors, when I realized that the generator is actually still under warranty and cutting sensor wires would probably void that warranty. So instead, I decided to just feel grateful that I had a backup for the backup generator, we’re not likely to need generator power much in the coming months, and we can see how well Generac’s warranty repair system works.
—2p