How often should you run an Onan 7.5KW we usually don't have a regular usage of ours we only have 44 hours in 13 years. we have 50 amp service here at the house and normally use the camp ground hookup...
You should run your generator once a month for an hour under load to keep moisture within the windings dried out. But lack of use can also cause the copper slip rings to oxidize therefore reducing or preventing any AC output.