Kitchen Aid superba convection elecectric oven model KE SC 30788T8?
Answers:
Go to the KitchenAid website below, and in the Troubleshooting section on the page, enter your model number (I tried the one you posted, it did not work, so it is probably not correct).
If that fails to work, call KitchenAid at the toll-free number posted on the site and see if the agent can help you acquire a manual.
Other answers: