Add an Asset Publisher to your page.
Click on Add New -> Contract.
Fill the Title, and browse a big (larger than 3000k) file.
When you click on Publish, an error message appears on the screen: "Please enter a file with a valid file size no larger than 3000k. ".
It is OK, but the dialog box changed from New Contract to New Document (title, fields).
It is the same, when you go to Control Panel -> Recent Content.