Yanche wrote:First select an engine based on the kind of fuel you normally would have, diesel (home heating oil), natural gas (re-jetted propane), propane or gasoline. There nothing worst than having a power outage, having the generator but not having good or sufficient fuel. The point is to use a fuel you have another use for and don't let it go stale. Noise is a consideration. 1800 RPM generators are less noisy. Generators designed for motor homes are the quietest. I've got a 15 KW whole house 1800 RPM 4-cyl diesel that I run on home heating oil. Bought cheap when the Y2K century change crisis never materialized. Many businesses ordered generators but never installed them. When there wasn't a problem they were returned, causing a glut of new but used generators.
Mine came with an automatic transfer switch that I've not installed. It would cost more than I'm willing to pay in materials and permits to do so. I just back feed my generator into the distribution panel via a removable 100 amp circuit breaker when needed. You need to be cautious but it's a safe method. My diesel has an one kilowatt electric block heater, intended to warm the coolant for instant start. I power it only when severe weather is predicted. Otherwise I depend on the manual start glow plugs.
the only thing you'd need to worry about is your neutral and ground, during one outage i had voltage across these.
something was funky on the street side.
all i doo now is check these with a meter and disconnect them from the main if needed.
as too pre heating your gen a small propane heater is a great back up in the event you weren't able to have the block heater on before the outage.
i have a 30kw 2-71 detroit. it runs at 1200rpm
my 2-71 is pre glow plugs so when it's below 30 it needs to be heated prior to starting.
i use a small propane heater or even better the heat from running the back up gas gen will work and power the house.