We carefully calculated the electrical load and it showed if we used the three PMM’s (power management modules) a 20kw generator would provide adequate power. What is the danger of undersizing the generator? Probably the worst issue would be if the generator became overloaded and shut down. The next issue is when the electrical inspector from Enumclaw, WA comes they could require a different generator be installed or circuits be removed from the generator.
We needed to trench for the LP gas to the Generator location.
The 20k was located just around the back corner of the house bolted to a 200lb concrete base.