Why do i have duplicated menu on wordpress?

Here i am creating 2 menu sites "Main" and "Central"

 if ( function_exists( 'register_nav_menus' ) ) {
     register_nav_menus(
          array(
              'main' => 'Main',
              'central' => 'Central' 
         )
     );
  }

when i am creating menus on wordpress aperience, menus and i am puting them on their sites PRS menu on Main and central on Central

When i have incerted my menus on web

       <?php wp_nav_menu( array('menu' => 'Main','menu_class' => 'menu' )); ?>
       <?php wp_nav_menu( array('menu' => 'Central','menu_class' => 'menu' )); ?>

But on my web i am seyng "central" menu 2 times and PRS dont apear. What is the problem and what solution cn i find?