I'm a relatively new homeowner (starting my third year) and I've been researching getting a 8000watt portable generator and having a manual transfer switch installed to power important appliances https://19216801.onl/ (fridge, freezer, electric range, potable well pump) etc.

Caveat - I barely know what I'm doing, and will have an electrician install the switch https://routerlogin.uno/.

Anyways, from what I can tell, all these transfer switches / gens use a 30amp 240v NEMA L14-30 cable from the gen to the exterior plug. My maths say 240x30 = 7200 watt. Some of these larger generators are 8000+ watts. Does that mean that above a certain size generator, you're going to have unused capacity as the outlet on the gen can only supply 30 amp? Is that the point where you would be looking at a standby generator instead of a cheaper portable, or am I missing something https://192168ll.link/?