Our MH has two roof a/c units but is only set up for 30A service. Running the generator is necessary if it's hot enough to need them both.
Our generator is an Onan with 5.5 KVA output and doesn't seem to breathing hard with both a/cs and a coffee maker. Most times we don't need dual a/c, so it hasn't been exercised much.
BTW, the 5500 was in the rig when we bought it used.
Frank and Eileen
No longer RVers or FR owners