Hager Flexible Circuit Breaker Dual RCD Boards and Devices\r\nThe Hager MTN Miniature Circuit Breakers MCBs detect overcurrents due to both overload and fault currents. The MTN range is Type B breakers, which means they will trip between 3 and 5 times full load current which is suitable for most domestic installations. The MCB will operate and interrupt the supply to prevent damage to the installation.