FuseBox 20A Single Pole 1 Module B Curve 6kA 30mA Type A RCBOFuseBox RCBO 20amp Type A B Curve RTA062030B Overview The RTA062030B RCBO is designed for use in FuseBox consumer units. These single pole Type A RCBOs respond to both AC and pulsating DC residual currents and protect against both overcurrent's due to overload and fault and residual current earth leakage. In either event, the RCBO interrupts the electrical supply to the circuit thus preventing damage to the installation and devices and electric shock