Emergency Generators

[DickR]

I went with a Kohler 14KW air-cooled generator, running off propane, with transfer switch installed as "service entrance," meaning that when in operation it supplies anything in the house. When I added up the power use of various "must have" things plus some "be nice to have for mostly normal living" things, I still was well below capacity. Of course one could overload it, with simulataneous use of high-draw things, like hair dryer (1.2 KW), oven (?, but high), microwave (1.5 KW), clothes dryer, and so on. But then I could always turn off the hot water heater breaker at the panel (4.5 KW) and gain a huge margin right there. Hot water recovery could wait until other activity is over.

One of the things that tipped the scales for me (Kohler vs Generac) was reading that the Kohler unit has hydraulic valve lifters, whereas the annual maintenance service description for a comparable Generac unit said the valve clearances had to be checked. A little thing, but I do my own annual servicing, which amounts to oil change, check the air filter, and perhaps check the spark plug gap. We don't have outages that often and usually are of short duration, so most hours on the meter are from the weekly 20-minute self-test.

There was a problem with the inlet propane valve as delivered, requiring replacement (under warranty), which was handled by Rowan, authorized by Kohler to install and service. I found him easy to work with and competent. I'm sure others are as well qualified. In the two years since startup, I haven't had any problem at all with the unit. After talking with Rowan, I did buy/install myself a carburetor heater, which prevents icing at low temperatures. The unit is fueled by a dedicated 500 gallon propane tank. That size was specified by the gas company. A tank half the size would not have enough surface area to absorb heat from the ambient air at 0 F temperature to vaporize propane at a rate needed to run a 14 KW generator at full capacity. There was no other propane service in the house, so the tank was required. To minimize cost, I dug myself the trenches for propane line to generator and electrical lines from generator to junction box at the house. The inside wiring was mostly installed at construction time, in anticipation of having a standby generator at some point. That took four years, but that was procrastination on my part.