Hello, maybe you already to get help but I still like to share the generator oil change time to you.
If your generator is a new genset, you should change oil when the unit runs 60 hours. After that, change the oil every 200 to 300 running hours.
In general, Perkins generator oil change is 500 hours.
If you want to know about Cummins generator, the following article will be helpful.
Cummins Oil Oil Change Intervals
If you want to inquire other brands of generator, you need to inquire your supplier or technical person.