Our transportable RCDs (Residual-Current Devices) are modular protection units designed for mobile use. They can be flexibly integrated into existing power distribution systems and provide reliable protection for people and equipment—wherever electrical energy is used on the move. Contact us for sales and pricing information. Why SENTRON residual current protective devices? SENTRON RCDs combine residual current detection and. Modular residual current devices (MRCD) are used to protect against residual currents, if residual current circuit-breakers cannot be used due to the high load currents or mains voltages. Suitable for residential, commercial, and industrial installations, RCDs continuously monitor. ABB's Control Room offering includes a comprehensive range of solutions designed to optimize the operator workspace for critical 24/7 processes across various industries.