A neutral section or phase break consists of two insulated breaks back-to-back with a short section of line that belongs to neither grid. Some systems increase the level of safety by the midpoint of the neutral section being earthed. The presence of the earthed section in the middle is to ensure that should the transducer controlled apparatus fail, and the driver also fail to shut off power, the energy in the arc struck by the pantograph as it passes to the neutral section is conducted to earth, operating substation circuit breakers, rather than the arc either bridging the insulators into a section made dead for maintenance, a section fed from a different phase, or setting up a Backdoor connection between different parts of the country's national grid.