Use custom image size in admin panel

I have add some image size like:

add_image_size( 'custom-small', 600, 600 );
add_image_size( 'custom-medium', 1280, 1280 );
add_image_size( 'custom-large', 2560, 2560 );

and I have removed all the default sizes. Now the Media Library in the Admin panel is loading full image instead of medium. Is it possible to specify a custom size to use?