Pelton problem

Just returned from the drugstore after picking up last weekend’s pictures. (Heh heh, remember those pre-digital days? I wonder what has happened to all those photo processing machines.) Shown above is the target of my Friday helicopter flight to the ranch, our gorgeous 63 thousand watt Pelton/General Electric hydroelectric power plant. Serving almost trouble-free since 1959, it gave us a fright when it wouldn’t properly regulate its speed. When a heavy load like the 9KW dishwasher heater or electric oven was turned on, the voltage dropped because the wheel wasn’t getting more water to compensate for the increased load.

When I arrived at the ranch, I entered the rock building and admired the machine’s smooth powerful sound, enhanced by the replacement of a worn bearing last season. Luke had torn into the main bearings on the turbine and was surprised to see that one of its roller bearings was evolving into a ball bearing! He had a replacement and put it in correctly (the original had one of its parts reversed). The old feeling of a slight vibration in the floor was now gone. Imagine what it took to shake a concrete foundation that’s three feet (0.9 meter) thick!

My admiration quickly vanished when I inserted the long steel rod into its socket which we use to start the wheel. Once it’s running, you can’t move that rod because you’re pushing against hydraulic pressure that regulates the speed of the wheel, a force that’s nearly half a ton. I pushed on the rod and the wheel slowly sped up! And it kept speeding up when I let go! Quickly I stomped my foot on the solenoid-operated valve that dumps the hydraulic pressure; it’s one of the safety shutoffs that prevent the machine from overspeeding and possibly disintegrating. After restarting it, I tried once more and got the same result. I shut it down. Time for diesel backup, and time to start dismantling the regulator.

Which I will cover in the next entry. Don’t touch that dial!